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<?xml version="1.0" encoding="utf-8"?>
<search>
<entry>
<title>使用TypeScript提升JavaScript代码质量</title>
<link href="/2025/03/23/article10/"/>
<url>/2025/03/23/article10/</url>
<content type="html"><![CDATA[<h1 id="使用TypeScript提升JavaScript代码质量"><a href="#使用TypeScript提升JavaScript代码质量" class="headerlink" title="使用TypeScript提升JavaScript代码质量"></a>使用TypeScript提升JavaScript代码质量</h1><h2 id="什么是TypeScript？"><a href="#什么是TypeScript？" class="headerlink" title="什么是TypeScript？"></a>什么是TypeScript？</h2><p>TypeScript是JavaScript的超集，增加了静态类型和其他特性，使得代码更健壮和可维护。</p><h2 id="安装TypeScript"><a href="#安装TypeScript" class="headerlink" title="安装TypeScript"></a>安装TypeScript</h2><p>使用npm安装TypeScript：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">npm install -g typescript</span><br></pre></td></tr></table></figure><h2 id="基本语法"><a href="#基本语法" class="headerlink" title="基本语法"></a>基本语法</h2><p>以下是一个简单的TypeScript示例：</p><figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">function</span> <span class="title function_">greeter</span>(<span class="params"><span class="attr">person</span>: <span class="built_in">string</span></span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="string">"Hello, "</span> + person;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">let</span> user = <span class="string">"Jane User"</span>;</span><br><span class="line"><span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="title function_">greeter</span>(user));</span><br></pre></td></tr></table></figure><h2 id="类型注解"><a href="#类型注解" class="headerlink" title="类型注解"></a>类型注解</h2><p>TypeScript允许你为变量和函数添加类型注解：</p><figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">let</span> <span class="attr">isDone</span>: <span class="built_in">boolean</span> = <span class="literal">false</span>;</span><br><span class="line"><span class="keyword">let</span> <span class="attr">decimal</span>: <span class="built_in">number</span> = <span class="number">6</span>;</span><br><span class="line"><span class="keyword">let</span> <span class="attr">color</span>: <span class="built_in">string</span> = <span class="string">"blue"</span>;</span><br><span class="line"><span class="keyword">let</span> <span class="attr">list</span>: <span class="built_in">number</span>[] = [<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>];</span><br></pre></td></tr></table></figure><h2 id="接口"><a href="#接口" class="headerlink" title="接口"></a>接口</h2><p>接口用于定义对象的结构：</p><figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">interface</span> <span class="title class_">Person</span> {</span><br><span class="line"> <span class="attr">firstName</span>: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">lastName</span>: <span class="built_in">string</span>;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">greeter</span>(<span class="params"><span class="attr">person</span>: <span class="title class_">Person</span></span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="string">"Hello, "</span> + person.<span class="property">firstName</span> + <span class="string">" "</span> + person.<span class="property">lastName</span>;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">let</span> user = { <span class="attr">firstName</span>: <span class="string">"Jane"</span>, <span class="attr">lastName</span>: <span class="string">"User"</span> };</span><br><span class="line"><span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="title function_">greeter</span>(user));</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>TypeScript通过引入静态类型检查和其他特性，显著提升了JavaScript代码的质量和可维护性。如果你正在编写大型JavaScript应用，强烈推荐使用TypeScript。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用TypeScript提升JavaScript代码质量] --> B[什么是TypeScript]</span><br><span class="line"> A --> C[安装TypeScript]</span><br><span class="line"> A --> D[基本语法]</span><br><span class="line"> A --> E[类型注解]</span><br><span class="line"> A --> F[接口]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>理解数据库事务</title>
<link href="/2025/03/23/article11/"/>
<url>/2025/03/23/article11/</url>
<content type="html"><![CDATA[<h1 id="理解数据库事务"><a href="#理解数据库事务" class="headerlink" title="理解数据库事务"></a>理解数据库事务</h1><h2 id="什么是数据库事务？"><a href="#什么是数据库事务？" class="headerlink" title="什么是数据库事务？"></a>什么是数据库事务？</h2><p>数据库事务是一组操作的集合，这些操作要么全部执行成功，要么全部回滚，以确保数据的一致性。</p><h2 id="ACID特性"><a href="#ACID特性" class="headerlink" title="ACID特性"></a>ACID特性</h2><p>事务具有四个重要特性，通常称为ACID：</p><ol><li><strong>原子性 (Atomicity)</strong>：事务中的所有操作要么全部完成，要么全部回滚。</li><li><strong>一致性 (Consistency)</strong>：事务执行前后，数据库保持一致状态。</li><li><strong>隔离性 (Isolation)</strong>：事务的执行不受其他事务的影响。</li><li><strong>持久性 (Durability)</strong>：一旦事务提交，结果永久保存。</li></ol><h2 id="使用事务"><a href="#使用事务" class="headerlink" title="使用事务"></a>使用事务</h2><p>以下是一个使用事务的示例：</p><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">BEGIN</span>;</span><br><span class="line"></span><br><span class="line"><span class="comment">-- 执行操作</span></span><br><span class="line"><span class="keyword">INSERT INTO</span> accounts (user_id, balance) <span class="keyword">VALUES</span> (<span class="number">1</span>, <span class="number">100</span>);</span><br><span class="line"><span class="keyword">UPDATE</span> accounts <span class="keyword">SET</span> balance <span class="operator">=</span> balance <span class="operator">-</span> <span class="number">50</span> <span class="keyword">WHERE</span> user_id <span class="operator">=</span> <span class="number">1</span>;</span><br><span class="line"></span><br><span class="line"><span class="comment">-- 提交事务</span></span><br><span class="line"><span class="keyword">COMMIT</span>;</span><br></pre></td></tr></table></figure><p>如果在事务过程中发生错误，可以回滚事务：</p><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">ROLLBACK</span>;</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>事务是保证数据库数据一致性和完整性的重要机制，理解并正确使用事务可以提高数据库操作的可靠性和安全性。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[理解数据库事务] --> B[什么是数据库事务]</span><br><span class="line"> A --> C[ACID特性]</span><br><span class="line"> A --> D[使用事务]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>理解微服务架构</title>
<link href="/2025/03/23/article13/"/>
<url>/2025/03/23/article13/</url>
<content type="html"><![CDATA[<h1 id="理解微服务架构"><a href="#理解微服务架构" class="headerlink" title="理解微服务架构"></a>理解微服务架构</h1><h2 id="什么是微服务架构？"><a href="#什么是微服务架构？" class="headerlink" title="什么是微服务架构？"></a>什么是微服务架构？</h2><p>微服务架构是一种软件架构风格，将应用程序拆分为一组小的、独立部署的服务，每个服务负责特定的业务功能。</p><h2 id="优点"><a href="#优点" class="headerlink" title="优点"></a>优点</h2><ol><li><strong>独立部署</strong>：每个服务可以独立开发、测试和部署，减少了开发周期。</li><li><strong>技术多样性</strong>：不同的服务可以使用不同的技术栈，选择最适合的技术。</li><li><strong>弹性和可扩展性</strong>：可以根据需求独立扩展服务，提高系统的弹性和可扩展性。</li></ol><h2 id="挑战"><a href="#挑战" class="headerlink" title="挑战"></a>挑战</h2><ol><li><strong>复杂性</strong>：管理和协调多个服务增加了系统的复杂性。</li><li><strong>通信开销</strong>：服务之间通过网络通信，增加了通信开销和延迟。</li><li><strong>数据一致性</strong>：保证跨服务的数据一致性是一个挑战。</li></ol><h2 id="实现微服务"><a href="#实现微服务" class="headerlink" title="实现微服务"></a>实现微服务</h2><p>使用Docker和Kubernetes实现微服务架构：</p><ol><li><strong>Docker</strong>：将每个服务打包成Docker镜像，并使用Docker Compose进行编排。</li><li><strong>Kubernetes</strong>：使用Kubernetes进行容器编排和管理，提高系统的可扩展性和可靠性。</li></ol><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>微服务架构是一种灵活且强大的架构风格，适用于构建复杂和大规模的分布式系统。理解其优点和挑战，合理设计和实现微服务架构，可以大幅提升系统的开发效率和运行稳定性。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[理解微服务架构] --> B[什么是微服务架构]</span><br><span class="line"> A --> C[优点]</span><br><span class="line"> A --> D[挑战]</span><br><span class="line"> A --> E[实现微服务]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>深入理解JavaScript闭包</title>
<link href="/2025/03/23/article1/"/>
<url>/2025/03/23/article1/</url>
<content type="html"><![CDATA[<h1 id="深入理解JavaScript闭包"><a href="#深入理解JavaScript闭包" class="headerlink" title="深入理解JavaScript闭包"></a>深入理解JavaScript闭包</h1><h2 id="什么是闭包？"><a href="#什么是闭包？" class="headerlink" title="什么是闭包？"></a>什么是闭包？</h2><p>闭包是指那些能够访问自由变量的函数。换句话说，闭包可以让你在一个函数内部访问其外部的变量。</p><h2 id="闭包的原理"><a href="#闭包的原理" class="headerlink" title="闭包的原理"></a>闭包的原理</h2><p>闭包的实现依赖于JavaScript的函数作用域链。当一个函数定义在另一个函数内部时，内部函数会形成一个包含外部函数变量的闭包。</p><h2 id="闭包的应用"><a href="#闭包的应用" class="headerlink" title="闭包的应用"></a>闭包的应用</h2><p>闭包常用于创建私有变量、实现函数柯里化和在事件处理器中保持状态。</p><h2 id="示例代码"><a href="#示例代码" class="headerlink" title="示例代码"></a>示例代码</h2><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">function</span> <span class="title function_">createCounter</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="keyword">let</span> count = <span class="number">0</span>;</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">function</span>(<span class="params"></span>) {</span><br><span class="line"> count++;</span><br><span class="line"> <span class="keyword">return</span> count;</span><br><span class="line"> };</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">const</span> counter = <span class="title function_">createCounter</span>();</span><br><span class="line"><span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="title function_">counter</span>()); <span class="comment">// 1</span></span><br><span class="line"><span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="title function_">counter</span>()); <span class="comment">// 2</span></span><br><span class="line"><span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="title function_">counter</span>()); <span class="comment">// 3</span></span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>闭包是JavaScript中一个强大的特性，理解并善用闭包可以让你写出更灵活、更强大的代码。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[JavaScript闭包] --> B[什么是闭包]</span><br><span class="line"> A --> C[闭包的原理]</span><br><span class="line"> A --> D[闭包的应用]</span><br><span class="line"> D --> E[私有变量]</span><br><span class="line"> D --> F[函数柯里化]</span><br><span class="line"> D --> G[事件处理器]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Python进行数据分析</title>
<link href="/2025/03/23/article12/"/>
<url>/2025/03/23/article12/</url>
<content type="html"><![CDATA[<h1 id="使用Python进行数据分析"><a href="#使用Python进行数据分析" class="headerlink" title="使用Python进行数据分析"></a>使用Python进行数据分析</h1><h2 id="安装必要的库"><a href="#安装必要的库" class="headerlink" title="安装必要的库"></a>安装必要的库</h2><p>使用pip安装Pandas和Matplotlib：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">pip install pandas matplotlib</span><br></pre></td></tr></table></figure><h2 id="读取数据"><a href="#读取数据" class="headerlink" title="读取数据"></a>读取数据</h2><p>使用Pandas读取CSV文件：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> pandas <span class="keyword">as</span> pd</span><br><span class="line"></span><br><span class="line">data = pd.read_csv(<span class="string">'data.csv'</span>)</span><br><span class="line"><span class="built_in">print</span>(data.head())</span><br></pre></td></tr></table></figure><h2 id="数据清洗"><a href="#数据清洗" class="headerlink" title="数据清洗"></a>数据清洗</h2><p>进行数据清洗和预处理：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 删除缺失值</span></span><br><span class="line">data.dropna(inplace=<span class="literal">True</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 转换数据类型</span></span><br><span class="line">data[<span class="string">'column'</span>] = data[<span class="string">'column'</span>].astype(<span class="string">'int'</span>)</span><br></pre></td></tr></table></figure><h2 id="数据分析"><a href="#数据分析" class="headerlink" title="数据分析"></a>数据分析</h2><p>进行基本的数据分析和统计：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 计算平均值</span></span><br><span class="line">mean_value = data[<span class="string">'column'</span>].mean()</span><br><span class="line"><span class="built_in">print</span>(<span class="string">f"Mean: <span class="subst">{mean_value}</span>"</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 分组统计</span></span><br><span class="line">grouped_data = data.groupby(<span class="string">'category'</span>).mean()</span><br><span class="line"><span class="built_in">print</span>(grouped_data)</span><br></pre></td></tr></table></figure><h2 id="数据可视化"><a href="#数据可视化" class="headerlink" title="数据可视化"></a>数据可视化</h2><p>使用Matplotlib进行数据可视化：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> matplotlib.pyplot <span class="keyword">as</span> plt</span><br><span class="line"></span><br><span class="line"><span class="comment"># 绘制柱状图</span></span><br><span class="line">data[<span class="string">'column'</span>].plot(kind=<span class="string">'bar'</span>)</span><br><span class="line">plt.show()</span><br><span class="line"></span><br><span class="line"><span class="comment"># 绘制折线图</span></span><br><span class="line">data[<span class="string">'column'</span>].plot(kind=<span class="string">'line'</span>)</span><br><span class="line">plt.show()</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Python提供了强大的数据分析工具，通过使用Pandas和Matplotlib，你可以轻松地进行数据读取、清洗、分析和可视化。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Python进行数据分析] --> B[安装必要的库]</span><br><span class="line"> A --> C[读取数据]</span><br><span class="line"> A --> D[数据清洗]</span><br><span class="line"> A --> E[数据分析]</span><br><span class="line"> A --> F[数据可视化]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用TensorFlow进行深度学习</title>
<link href="/2025/03/23/article14/"/>
<url>/2025/03/23/article14/</url>
<content type="html"><![CDATA[<h1 id="使用TensorFlow进行深度学习"><a href="#使用TensorFlow进行深度学习" class="headerlink" title="使用TensorFlow进行深度学习"></a>使用TensorFlow进行深度学习</h1><h2 id="安装TensorFlow"><a href="#安装TensorFlow" class="headerlink" title="安装TensorFlow"></a>安装TensorFlow</h2><p>使用pip安装TensorFlow：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">pip install tensorflow</span><br></pre></td></tr></table></figure><h2 id="创建简单的神经网络"><a href="#创建简单的神经网络" class="headerlink" title="创建简单的神经网络"></a>创建简单的神经网络</h2><p>以下是一个使用TensorFlow创建简单神经网络的示例：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> tensorflow <span class="keyword">as</span> tf</span><br><span class="line"><span class="keyword">from</span> tensorflow.keras.models <span class="keyword">import</span> Sequential</span><br><span class="line"><span class="keyword">from</span> tensorflow.keras.layers <span class="keyword">import</span> Dense</span><br><span class="line"></span><br><span class="line"><span class="comment"># 创建模型</span></span><br><span class="line">model = Sequential([</span><br><span class="line"> Dense(<span class="number">128</span>, activation=<span class="string">'relu'</span>, input_shape=(<span class="number">784</span>,)),</span><br><span class="line"> Dense(<span class="number">64</span>, activation=<span class="string">'relu'</span>),</span><br><span class="line"> Dense(<span class="number">10</span>, activation=<span class="string">'softmax'</span>)</span><br><span class="line">])</span><br><span class="line"></span><br><span class="line"><span class="comment"># 编译模型</span></span><br><span class="line">model.<span class="built_in">compile</span>(optimizer=<span class="string">'adam'</span>,</span><br><span class="line"> loss=<span class="string">'sparse_categorical_crossentropy'</span>,</span><br><span class="line"> metrics=[<span class="string">'accuracy'</span>])</span><br><span class="line"></span><br><span class="line"><span class="comment"># 训练模型</span></span><br><span class="line">model.fit(x_train, y_train, epochs=<span class="number">5</span>)</span><br></pre></td></tr></table></figure><h2 id="评估模型"><a href="#评估模型" class="headerlink" title="评估模型"></a>评估模型</h2><p>评估模型的性能：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">loss, accuracy = model.evaluate(x_test, y_test)</span><br><span class="line"><span class="built_in">print</span>(<span class="string">f"Test accuracy: <span class="subst">{accuracy}</span>"</span>)</span><br></pre></td></tr></table></figure><h2 id="预测"><a href="#预测" class="headerlink" title="预测"></a>预测</h2><p>使用训练好的模型进行预测：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">predictions = model.predict(x_test)</span><br><span class="line"><span class="built_in">print</span>(predictions[<span class="number">0</span>])</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>TensorFlow是一个强大的深度学习框架，通过其高层API，开发者可以快速构建和训练神经网络模型。本文介绍了如何使用TensorFlow进行基本的深度学习任务，帮助你快速入门。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用TensorFlow进行深度学习] --> B[安装TensorFlow]</span><br><span class="line"> A --> C[创建简单的神经网络]</span><br><span class="line"> A --> D[评估模型]</span><br><span class="line"> A --> E[预测]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用GraphQL构建灵活的API</title>
<link href="/2025/03/23/article18/"/>
<url>/2025/03/23/article18/</url>
<content type="html"><![CDATA[<h1 id="使用GraphQL构建灵活的API"><a href="#使用GraphQL构建灵活的API" class="headerlink" title="使用GraphQL构建灵活的API"></a>使用GraphQL构建灵活的API</h1><h2 id="什么是GraphQL？"><a href="#什么是GraphQL？" class="headerlink" title="什么是GraphQL？"></a>什么是GraphQL？</h2><p>GraphQL是由Facebook开发的一个用于API的查询语言，它提供了比传统REST API更灵活和高效的数据获取方式。</p><h2 id="GraphQL的基本概念"><a href="#GraphQL的基本概念" class="headerlink" title="GraphQL的基本概念"></a>GraphQL的基本概念</h2><ol><li><strong>Schema</strong>：定义API的类型和结构。</li><li><strong>Query</strong>：用于获取数据的请求。</li><li><strong>Mutation</strong>：用于修改数据的请求。</li><li><strong>Resolver</strong>：处理查询和变更请求的函数。</li></ol><h2 id="示例"><a href="#示例" class="headerlink" title="示例"></a>示例</h2><p>以下是一个简单的GraphQL服务器示例（使用Node.js和Express）：</p><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> express = <span class="built_in">require</span>(<span class="string">'express'</span>);</span><br><span class="line"><span class="keyword">const</span> { graphqlHTTP } = <span class="built_in">require</span>(<span class="string">'express-graphql'</span>);</span><br><span class="line"><span class="keyword">const</span> { buildSchema } = <span class="built_in">require</span>(<span class="string">'graphql'</span>);</span><br><span class="line"></span><br><span class="line"><span class="comment">// 定义Schema</span></span><br><span class="line"><span class="keyword">const</span> schema = <span class="title function_">buildSchema</span>(<span class="string">`</span></span><br><span class="line"><span class="string"> type Query {</span></span><br><span class="line"><span class="string"> hello: String</span></span><br><span class="line"><span class="string"> }</span></span><br><span class="line"><span class="string">`</span>);</span><br><span class="line"></span><br><span class="line"><span class="comment">// 定义Resolver</span></span><br><span class="line"><span class="keyword">const</span> root = {</span><br><span class="line"> <span class="attr">hello</span>: <span class="function">() =></span> <span class="string">'Hello, world!'</span></span><br><span class="line">};</span><br><span class="line"></span><br><span class="line"><span class="comment">// 创建Express应用</span></span><br><span class="line"><span class="keyword">const</span> app = <span class="title function_">express</span>();</span><br><span class="line">app.<span class="title function_">use</span>(<span class="string">'/graphql'</span>, <span class="title function_">graphqlHTTP</span>({</span><br><span class="line"> <span class="attr">schema</span>: schema,</span><br><span class="line"> <span class="attr">rootValue</span>: root,</span><br><span class="line"> <span class="attr">graphiql</span>: <span class="literal">true</span>,</span><br><span class="line">}));</span><br><span class="line"></span><br><span class="line"><span class="comment">// 启动服务器</span></span><br><span class="line">app.<span class="title function_">listen</span>(<span class="number">4000</span>, <span class="function">() =></span> {</span><br><span class="line"> <span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="string">'Running a GraphQL API server at http://localhost:4000/graphql'</span>);</span><br><span class="line">});</span><br></pre></td></tr></table></figure><h2 id="使用GraphiQL进行查询"><a href="#使用GraphiQL进行查询" class="headerlink" title="使用GraphiQL进行查询"></a>使用GraphiQL进行查询</h2><p>启动服务器后，可以在浏览器中打开<a href="http://localhost:4000/graphql%EF%BC%8C%E4%BD%BF%E7%94%A8GraphiQL%E8%BF%9B%E8%A1%8C%E6%9F%A5%E8%AF%A2%EF%BC%9A">http://localhost:4000/graphql，使用GraphiQL进行查询：</a></p><figure class="highlight graphql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">{</span></span><br><span class="line"> hello</span><br><span class="line"><span class="punctuation">}</span></span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>GraphQL通过其灵活的查询语言和强大的类型系统，提供了比传统REST API更高效的数据获取方式。通过本文的介绍，你可以快速上手并开始使用GraphQL构建API。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用GraphQL构建灵活的API] --> B[什么是GraphQL]</span><br><span class="line"> A --> C[GraphQL的基本概念]</span><br><span class="line"> A --> D[示例]</span><br><span class="line"> A --> E[使用GraphiQL进行查询]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Nginx进行负载均衡</title>
<link href="/2025/03/23/article15/"/>
<url>/2025/03/23/article15/</url>
<content type="html"><![CDATA[<h1 id="使用Nginx进行负载均衡"><a href="#使用Nginx进行负载均衡" class="headerlink" title="使用Nginx进行负载均衡"></a>使用Nginx进行负载均衡</h1><h2 id="什么是负载均衡？"><a href="#什么是负载均衡？" class="headerlink" title="什么是负载均衡？"></a>什么是负载均衡？</h2><p>负载均衡是一种将网络流量分配到多个服务器的技术，以提高系统的可用性和性能。</p><h2 id="安装Nginx"><a href="#安装Nginx" class="headerlink" title="安装Nginx"></a>安装Nginx</h2><p>使用以下命令在Ubuntu上安装Nginx：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> apt-get update</span><br><span class="line"><span class="built_in">sudo</span> apt-get install -y nginx</span><br></pre></td></tr></table></figure><h2 id="配置负载均衡"><a href="#配置负载均衡" class="headerlink" title="配置负载均衡"></a>配置负载均衡</h2><p>编辑Nginx配置文件，添加负载均衡配置：</p><figure class="highlight nginx"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="section">http</span> {</span><br><span class="line"> <span class="section">upstream</span> myapp {</span><br><span class="line"> <span class="attribute">server</span> backend1.example.com;</span><br><span class="line"> <span class="attribute">server</span> backend2.example.com;</span><br><span class="line"> <span class="attribute">server</span> backend3.example.com;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="section">server</span> {</span><br><span class="line"> <span class="attribute">listen</span> <span class="number">80</span>;</span><br><span class="line"></span><br><span class="line"> <span class="section">location</span> / {</span><br><span class="line"> <span class="attribute">proxy_pass</span> http://myapp;</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="启动Nginx"><a href="#启动Nginx" class="headerlink" title="启动Nginx"></a>启动Nginx</h2><p>启动Nginx服务：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> systemctl start nginx</span><br><span class="line"><span class="built_in">sudo</span> systemctl <span class="built_in">enable</span> nginx</span><br></pre></td></tr></table></figure><h2 id="验证负载均衡"><a href="#验证负载均衡" class="headerlink" title="验证负载均衡"></a>验证负载均衡</h2><p>访问Nginx服务器的IP地址，验证负载均衡是否正常工作。</p><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>通过Nginx进行负载均衡，可以有效提高Web应用的可用性和性能。本文介绍了基本的负载均衡配置，帮助你快速上手。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Nginx进行负载均衡] --> B[什么是负载均衡]</span><br><span class="line"> A --> C[安装Nginx]</span><br><span class="line"> A --> D[配置负载均衡]</span><br><span class="line"> A --> E[启动Nginx]</span><br><span class="line"> A --> F[验证负载均衡]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Redis进行缓存</title>
<link href="/2025/03/23/article16/"/>
<url>/2025/03/23/article16/</url>
<content type="html"><![CDATA[<h1 id="使用Redis进行缓存"><a href="#使用Redis进行缓存" class="headerlink" title="使用Redis进行缓存"></a>使用Redis进行缓存</h1><h2 id="什么是Redis？"><a href="#什么是Redis？" class="headerlink" title="什么是Redis？"></a>什么是Redis？</h2><p>Redis是一个开源的内存数据库，支持多种数据结构，常用于缓存、会话存储和消息队列等场景。</p><h2 id="安装Redis"><a href="#安装Redis" class="headerlink" title="安装Redis"></a>安装Redis</h2><p>使用以下命令在Ubuntu上安装Redis：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> apt-get update</span><br><span class="line"><span class="built_in">sudo</span> apt-get install -y redis-server</span><br></pre></td></tr></table></figure><p>启动Redis服务：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> systemctl start redis</span><br><span class="line"><span class="built_in">sudo</span> systemctl <span class="built_in">enable</span> redis</span><br></pre></td></tr></table></figure><h2 id="基本操作"><a href="#基本操作" class="headerlink" title="基本操作"></a>基本操作</h2><p>连接Redis服务器：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">redis-cli</span><br></pre></td></tr></table></figure><p>设置键值对：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">SET key <span class="string">"value"</span></span><br></pre></td></tr></table></figure><p>获取键值：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">GET key</span><br></pre></td></tr></table></figure><h2 id="使用Redis进行缓存-1"><a href="#使用Redis进行缓存-1" class="headerlink" title="使用Redis进行缓存"></a>使用Redis进行缓存</h2><p>以下是一个使用Redis进行缓存的示例（Python）：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> redis</span><br><span class="line"></span><br><span class="line"><span class="comment"># 连接Redis</span></span><br><span class="line">r = redis.Redis(host=<span class="string">'localhost'</span>, port=<span class="number">6379</span>, db=<span class="number">0</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 设置缓存</span></span><br><span class="line">r.<span class="built_in">set</span>(<span class="string">'my_key'</span>, <span class="string">'my_value'</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 获取缓存</span></span><br><span class="line">value = r.get(<span class="string">'my_key'</span>)</span><br><span class="line"><span class="built_in">print</span>(value)</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Redis是一个高性能的内存数据库，通过使用Redis进行缓存，可以显著提高应用程序的性能。本文介绍了Redis的基本概念和操作，帮助你快速上手。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Redis进行缓存] --> B[什么是Redis]</span><br><span class="line"> A --> C[安装Redis]</span><br><span class="line"> A --> D[基本操作]</span><br><span class="line"> A --> E[使用Redis进行缓存]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Ansible进行自动化运维</title>
<link href="/2025/03/23/article19/"/>
<url>/2025/03/23/article19/</url>
<content type="html"><![CDATA[<h1 id="使用Ansible进行自动化运维"><a href="#使用Ansible进行自动化运维" class="headerlink" title="使用Ansible进行自动化运维"></a>使用Ansible进行自动化运维</h1><h2 id="什么是Ansible？"><a href="#什么是Ansible？" class="headerlink" title="什么是Ansible？"></a>什么是Ansible？</h2><p>Ansible是一个开源的自动化工具，用于配置管理、应用部署和任务自动化。它通过SSH进行通信，无需在目标主机上安装代理软件。</p><h2 id="安装Ansible"><a href="#安装Ansible" class="headerlink" title="安装Ansible"></a>安装Ansible</h2><p>使用以下命令在Ubuntu上安装Ansible：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> apt-get update</span><br><span class="line"><span class="built_in">sudo</span> apt-get install -y ansible</span><br></pre></td></tr></table></figure><h2 id="基本概念"><a href="#基本概念" class="headerlink" title="基本概念"></a>基本概念</h2><ol><li><strong>Playbook</strong>：定义自动化任务的YAML文件。</li><li><strong>Inventory</strong>：定义主机和组的清单文件。</li><li><strong>Module</strong>：Ansible中执行具体任务的单元。</li></ol><h2 id="示例"><a href="#示例" class="headerlink" title="示例"></a>示例</h2><p>以下是一个简单的Ansible Playbook示例，用于安装Nginx：</p><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">---</span></span><br><span class="line"><span class="bullet">-</span> <span class="attr">hosts:</span> <span class="string">webservers</span></span><br><span class="line"> <span class="attr">become:</span> <span class="literal">yes</span></span><br><span class="line"> <span class="attr">tasks:</span></span><br><span class="line"> <span class="bullet">-</span> <span class="attr">name:</span> <span class="string">安装Nginx</span></span><br><span class="line"> <span class="attr">apt:</span></span><br><span class="line"> <span class="attr">name:</span> <span class="string">nginx</span></span><br><span class="line"> <span class="attr">state:</span> <span class="string">present</span></span><br></pre></td></tr></table></figure><p>定义Inventory文件（hosts）：</p><figure class="highlight ini"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="section">[webservers]</span></span><br><span class="line">192.168.1.10</span><br><span class="line">192.168.1.11</span><br></pre></td></tr></table></figure><p>运行Playbook：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">ansible-playbook -i hosts playbook.yml</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Ansible通过其简单且强大的自动化功能，可以显著提高运维效率。本文介绍了Ansible的基本概念和使用方法，帮助你快速上手。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Ansible进行自动化运维] --> B[什么是Ansible]</span><br><span class="line"> A --> C[安装Ansible]</span><br><span class="line"> A --> D[基本概念]</span><br><span class="line"> A --> E[示例]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Flutter构建跨平台移动应用</title>
<link href="/2025/03/23/article20/"/>
<url>/2025/03/23/article20/</url>
<content type="html"><![CDATA[<h1 id="使用Flutter构建跨平台移动应用"><a href="#使用Flutter构建跨平台移动应用" class="headerlink" title="使用Flutter构建跨平台移动应用"></a>使用Flutter构建跨平台移动应用</h1><h2 id="什么是Flutter？"><a href="#什么是Flutter？" class="headerlink" title="什么是Flutter？"></a>什么是Flutter？</h2><p>Flutter是Google开发的一个开源框架，用于构建高性能、跨平台的移动应用。它使用Dart语言，并提供丰富的组件和工具。</p><h2 id="安装Flutter"><a href="#安装Flutter" class="headerlink" title="安装Flutter"></a>安装Flutter</h2><p>按照以下步骤安装Flutter：</p><ol><li>从<a href="https://flutter.dev/">Flutter官网</a>下载Flutter SDK。</li><li>解压缩下载的文件并将其路径添加到环境变量中。</li><li>验证安装：</li></ol><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">flutter doctor</span><br></pre></td></tr></table></figure><h2 id="创建Flutter应用"><a href="#创建Flutter应用" class="headerlink" title="创建Flutter应用"></a>创建Flutter应用</h2><p>使用以下命令创建一个新的Flutter应用：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">flutter create my_app</span><br><span class="line"><span class="built_in">cd</span> my_app</span><br></pre></td></tr></table></figure><h2 id="编写代码"><a href="#编写代码" class="headerlink" title="编写代码"></a>编写代码</h2><p>以下是一个简单的Flutter应用示例：</p><figure class="highlight dart"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> <span class="string">'package:flutter/material.dart'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">void</span> main() {</span><br><span class="line"> runApp(MyApp());</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="class"><span class="keyword">class</span> <span class="title">MyApp</span> <span class="keyword">extends</span> <span class="title">StatelessWidget</span> </span>{</span><br><span class="line"> <span class="meta">@override</span></span><br><span class="line"> Widget build(BuildContext context) {</span><br><span class="line"> <span class="keyword">return</span> MaterialApp(</span><br><span class="line"> home: Scaffold(</span><br><span class="line"> appBar: AppBar(</span><br><span class="line"> title: Text(<span class="string">'Flutter Demo'</span>),</span><br><span class="line"> ),</span><br><span class="line"> body: Center(</span><br><span class="line"> child: Text(<span class="string">'Hello, Flutter!'</span>),</span><br><span class="line"> ),</span><br><span class="line"> ),</span><br><span class="line"> );</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="运行应用"><a href="#运行应用" class="headerlink" title="运行应用"></a>运行应用</h2><p>使用以下命令运行Flutter应用：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">flutter run</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Flutter通过其高性能和跨平台特性，使得移动应用开发变得更加高效和便捷。本文介绍了Flutter的基本概念和使用方法，帮助你快速上手并开始构建跨平台移动应用。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Flutter构建跨平台移动应用] --> B[什么是Flutter]</span><br><span class="line"> A --> C[安装Flutter]</span><br><span class="line"> A --> D[创建Flutter应用]</span><br><span class="line"> A --> E[编写代码]</span><br><span class="line"> A --> F[运行应用]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Docker进行容器化部署</title>
<link href="/2025/03/23/article2/"/>
<url>/2025/03/23/article2/</url>
<content type="html"><![CDATA[<h1 id="使用Docker进行容器化部署"><a href="#使用Docker进行容器化部署" class="headerlink" title="使用Docker进行容器化部署"></a>使用Docker进行容器化部署</h1><h2 id="什么是Docker？"><a href="#什么是Docker？" class="headerlink" title="什么是Docker？"></a>什么是Docker？</h2><p>Docker是一个开源的容器化平台，它使得开发者能够打包应用及其依赖项到一个轻量级的、可移植的容器中。</p><h2 id="安装Docker"><a href="#安装Docker" class="headerlink" title="安装Docker"></a>安装Docker</h2><p>在不同的操作系统上安装Docker的步骤略有不同，以下是一些常见操作系统的安装步骤：</p><h3 id="在Ubuntu上安装Docker"><a href="#在Ubuntu上安装Docker" class="headerlink" title="在Ubuntu上安装Docker"></a>在Ubuntu上安装Docker</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">sudo</span> apt-get update</span><br><span class="line"><span class="built_in">sudo</span> apt-get install -y docker.io</span><br><span class="line"><span class="built_in">sudo</span> systemctl start docker</span><br><span class="line"><span class="built_in">sudo</span> systemctl <span class="built_in">enable</span> docker</span><br></pre></td></tr></table></figure><h3 id="在Windows上安装Docker"><a href="#在Windows上安装Docker" class="headerlink" title="在Windows上安装Docker"></a>在Windows上安装Docker</h3><ol><li>下载Docker Desktop安装包</li><li>双击安装包并按照提示完成安装</li><li>启动Docker Desktop</li></ol><h2 id="使用Docker进行容器化部署-1"><a href="#使用Docker进行容器化部署-1" class="headerlink" title="使用Docker进行容器化部署"></a>使用Docker进行容器化部署</h2><h3 id="创建Dockerfile"><a href="#创建Dockerfile" class="headerlink" title="创建Dockerfile"></a>创建Dockerfile</h3><p>Dockerfile是一个文本文件，其中包含了构建Docker镜像的指令。以下是一个简单的示例：</p><figure class="highlight dockerfile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 选择基础镜像</span></span><br><span class="line"><span class="keyword">FROM</span> node:<span class="number">14</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 创建应用目录</span></span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /app</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 复制项目文件</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> . /app</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 安装依赖</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> npm install</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 启动应用</span></span><br><span class="line"><span class="keyword">CMD</span><span class="language-bash"> [<span class="string">"npm"</span>, <span class="string">"start"</span>]</span></span><br></pre></td></tr></table></figure><h3 id="构建Docker镜像"><a href="#构建Docker镜像" class="headerlink" title="构建Docker镜像"></a>构建Docker镜像</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">docker build -t my-app .</span><br></pre></td></tr></table></figure><h3 id="运行Docker容器"><a href="#运行Docker容器" class="headerlink" title="运行Docker容器"></a>运行Docker容器</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">docker run -d -p 3000:3000 my-app</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>通过Docker，开发者可以轻松地进行应用的容器化部署，提高开发和运维的效率。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Docker进行容器化部署] --> B[什么是Docker]</span><br><span class="line"> A --> C[安装Docker]</span><br><span class="line"> A --> D[使用Docker进行容器化部署]</span><br><span class="line"> D --> E[创建Dockerfile]</span><br><span class="line"> D --> F[构建Docker镜像]</span><br><span class="line"> D --> G[运行Docker容器]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>理解RESTful API设计</title>
<link href="/2025/03/23/article4/"/>
<url>/2025/03/23/article4/</url>
<content type="html"><![CDATA[<h1 id="理解RESTful-API设计"><a href="#理解RESTful-API设计" class="headerlink" title="理解RESTful API设计"></a>理解RESTful API设计</h1><h2 id="什么是RESTful-API？"><a href="#什么是RESTful-API？" class="headerlink" title="什么是RESTful API？"></a>什么是RESTful API？</h2><p>REST（Representational State Transfer）是一种设计风格，用于构建可扩展的Web服务。RESTful API遵循这一设计风格，使用HTTP协议进行通信。</p><h2 id="设计原则"><a href="#设计原则" class="headerlink" title="设计原则"></a>设计原则</h2><ol><li><strong>资源的表示</strong>：每个资源使用URI进行唯一标识，并通过HTTP方法进行操作（GET, POST, PUT, DELETE）。</li><li><strong>无状态性</strong>：每个请求都是独立的，包含所有必要的信息。</li><li><strong>统一接口</strong>：使用标准的HTTP方法和状态码。</li><li><strong>客户端-服务器架构</strong>：客户端和服务器职责分离，提高系统的可扩展性。</li></ol><h2 id="最佳实践"><a href="#最佳实践" class="headerlink" title="最佳实践"></a>最佳实践</h2><ol><li><strong>使用名词表示资源</strong>：例如，/users表示用户资源。</li><li><strong>使用HTTP状态码</strong>：例如，200表示成功，404表示资源未找到。</li><li><strong>版本控制</strong>：在URL中包含版本号，例如/v1/users。</li><li><strong>分页和过滤</strong>：对于大量数据，提供分页和过滤功能。</li></ol><h2 id="示例"><a href="#示例" class="headerlink" title="示例"></a>示例</h2><p>以下是一个简单的RESTful API示例：</p><figure class="highlight http"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">GET /api/v1/users</span><br><span class="line"><span class="attribute">Host</span><span class="punctuation">: </span>example.com</span><br><span class="line"><span class="attribute">Accept</span><span class="punctuation">: </span>application/json</span><br></pre></td></tr></table></figure><p>响应：</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">[</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"id"</span><span class="punctuation">:</span> <span class="number">1</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"John Doe"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"id"</span><span class="punctuation">:</span> <span class="number">2</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"Jane Doe"</span></span><br><span class="line"> <span class="punctuation">}</span></span><br><span class="line"><span class="punctuation">]</span></span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>RESTful API设计是一种构建Web服务的流行方法，遵循其原则和最佳实践可以提高API的可维护性和可扩展性。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[理解RESTful API设计] --> B[什么是RESTful API]</span><br><span class="line"> A --> C[设计原则]</span><br><span class="line"> A --> D[最佳实践]</span><br><span class="line"> A --> E[示例]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>Git的基本操作指南</title>
<link href="/2025/03/23/article3/"/>
<url>/2025/03/23/article3/</url>
<content type="html"><![CDATA[<h1 id="Git的基本操作指南"><a href="#Git的基本操作指南" class="headerlink" title="Git的基本操作指南"></a>Git的基本操作指南</h1><h2 id="初始化Git仓库"><a href="#初始化Git仓库" class="headerlink" title="初始化Git仓库"></a>初始化Git仓库</h2><p>在一个新的项目目录中初始化Git仓库：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">git init</span><br></pre></td></tr></table></figure><h2 id="提交更改"><a href="#提交更改" class="headerlink" title="提交更改"></a>提交更改</h2><p>添加文件到暂存区并提交：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">git add .</span><br><span class="line">git commit -m <span class="string">"Initial commit"</span></span><br></pre></td></tr></table></figure><h2 id="分支管理"><a href="#分支管理" class="headerlink" title="分支管理"></a>分支管理</h2><p>创建新分支并切换到该分支：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">git branch new-feature</span><br><span class="line">git checkout new-feature</span><br></pre></td></tr></table></figure><p>合并分支：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">git checkout main</span><br><span class="line">git merge new-feature</span><br></pre></td></tr></table></figure><h2 id="查看历史记录"><a href="#查看历史记录" class="headerlink" title="查看历史记录"></a>查看历史记录</h2><p>查看提交历史：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">git <span class="built_in">log</span></span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Git是一个功能强大的版本控制系统，掌握其基本操作将有助于更高效地管理代码。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[Git的基本操作指南] --> B[初始化Git仓库]</span><br><span class="line"> A --> C[提交更改]</span><br><span class="line"> A --> D[分支管理]</span><br><span class="line"> A --> E[查看历史记录]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用React Hooks进行状态管理</title>
<link href="/2025/03/23/article5/"/>
<url>/2025/03/23/article5/</url>
<content type="html"><![CDATA[<h1 id="使用React-Hooks进行状态管理"><a href="#使用React-Hooks进行状态管理" class="headerlink" title="使用React Hooks进行状态管理"></a>使用React Hooks进行状态管理</h1><h2 id="什么是React-Hooks？"><a href="#什么是React-Hooks？" class="headerlink" title="什么是React Hooks？"></a>什么是React Hooks？</h2><p>React Hooks是React 16.8引入的新特性，它允许你在不编写class组件的情况下使用状态和其他React特性。</p><h2 id="useState"><a href="#useState" class="headerlink" title="useState"></a>useState</h2><p>useState是一个用于在函数组件中添加状态的Hook。以下是一个简单的示例：</p><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> <span class="title class_">React</span>, { useState } <span class="keyword">from</span> <span class="string">'react'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">Counter</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="keyword">const</span> [count, setCount] = <span class="title function_">useState</span>(<span class="number">0</span>);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> (</span><br><span class="line"> <span class="language-xml"><span class="tag"><<span class="name">div</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"><<span class="name">p</span>></span>You clicked {count} times<span class="tag"></<span class="name">p</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"><<span class="name">button</span> <span class="attr">onClick</span>=<span class="string">{()</span> =></span> setCount(count + 1)}></span></span><br><span class="line"><span class="language-xml"> Click me</span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">button</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">div</span>></span></span></span><br><span class="line"> );</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="useEffect"><a href="#useEffect" class="headerlink" title="useEffect"></a>useEffect</h2><p>useEffect是一个用于在函数组件中执行副作用的Hook。以下是一个示例：</p><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> <span class="title class_">React</span>, { useState, useEffect } <span class="keyword">from</span> <span class="string">'react'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">Example</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="keyword">const</span> [count, setCount] = <span class="title function_">useState</span>(<span class="number">0</span>);</span><br><span class="line"></span><br><span class="line"> <span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="variable language_">document</span>.<span class="property">title</span> = <span class="string">`You clicked <span class="subst">${count}</span> times`</span>;</span><br><span class="line"> }, [count]);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> (</span><br><span class="line"> <span class="language-xml"><span class="tag"><<span class="name">div</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"><<span class="name">p</span>></span>You clicked {count} times<span class="tag"></<span class="name">p</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"><<span class="name">button</span> <span class="attr">onClick</span>=<span class="string">{()</span> =></span> setCount(count + 1)}></span></span><br><span class="line"><span class="language-xml"> Click me</span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">button</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">div</span>></span></span></span><br><span class="line"> );</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>React Hooks使得在函数组件中管理状态和副作用变得更加简单和直观，鼓励你在项目中尝试使用它们。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用React Hooks进行状态管理] --> B[什么是React Hooks]</span><br><span class="line"> A --> C[useState]</span><br><span class="line"> A --> D[useEffect]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>Python中的面向对象编程</title>
<link href="/2025/03/23/article6/"/>
<url>/2025/03/23/article6/</url>
<content type="html"><![CDATA[<h1 id="Python中的面向对象编程"><a href="#Python中的面向对象编程" class="headerlink" title="Python中的面向对象编程"></a>Python中的面向对象编程</h1><h2 id="什么是面向对象编程？"><a href="#什么是面向对象编程？" class="headerlink" title="什么是面向对象编程？"></a>什么是面向对象编程？</h2><p>面向对象编程（OOP）是一种编程范式，它将程序组织为对象的集合，每个对象都包含数据和行为。</p><h2 id="定义类和对象"><a href="#定义类和对象" class="headerlink" title="定义类和对象"></a>定义类和对象</h2><p>在Python中，类使用class关键字定义，对象是类的实例。以下是一个简单的示例：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">Dog</span>:</span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">__init__</span>(<span class="params">self, name, age</span>):</span><br><span class="line"> <span class="variable language_">self</span>.name = name</span><br><span class="line"> <span class="variable language_">self</span>.age = age</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">bark</span>(<span class="params">self</span>):</span><br><span class="line"> <span class="built_in">print</span>(<span class="string">f"<span class="subst">{self.name}</span> is barking"</span>)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 创建对象</span></span><br><span class="line">dog1 = Dog(<span class="string">"Buddy"</span>, <span class="number">3</span>)</span><br><span class="line">dog1.bark()</span><br></pre></td></tr></table></figure><h2 id="继承"><a href="#继承" class="headerlink" title="继承"></a>继承</h2><p>继承允许一个类继承另一个类的属性和方法。以下是一个示例：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">Animal</span>:</span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">__init__</span>(<span class="params">self, name</span>):</span><br><span class="line"> <span class="variable language_">self</span>.name = name</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">speak</span>(<span class="params">self</span>):</span><br><span class="line"> <span class="keyword">raise</span> NotImplementedError(<span class="string">"Subclass must implement abstract method"</span>)</span><br><span class="line"></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">Dog</span>(<span class="title class_ inherited__">Animal</span>):</span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">speak</span>(<span class="params">self</span>):</span><br><span class="line"> <span class="keyword">return</span> <span class="string">f"<span class="subst">{self.name}</span> says woof"</span></span><br><span class="line"></span><br><span class="line">dog = Dog(<span class="string">"Buddy"</span>)</span><br><span class="line"><span class="built_in">print</span>(dog.speak())</span><br></pre></td></tr></table></figure><h2 id="多态"><a href="#多态" class="headerlink" title="多态"></a>多态</h2><p>多态允许你在不考虑对象具体类型的情况下使用对象。以下是一个示例：</p><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">make_animal_speak</span>(<span class="params">animal</span>):</span><br><span class="line"> <span class="built_in">print</span>(animal.speak())</span><br><span class="line"></span><br><span class="line">dog = Dog(<span class="string">"Buddy"</span>)</span><br><span class="line">make_animal_speak(dog)</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>面向对象编程是Python中的一个重要概念，理解并掌握OOP可以帮助你编写更具组织性和可维护性的代码。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[Python中的面向对象编程] --> B[什么是面向对象编程]</span><br><span class="line"> A --> C[定义类和对象]</span><br><span class="line"> A --> D[继承]</span><br><span class="line"> A --> E[多态]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>使用Node.js构建RESTful API</title>
<link href="/2025/03/23/article7/"/>
<url>/2025/03/23/article7/</url>
<content type="html"><![CDATA[<h1 id="使用Node-js构建RESTful-API"><a href="#使用Node-js构建RESTful-API" class="headerlink" title="使用Node.js构建RESTful API"></a>使用Node.js构建RESTful API</h1><h2 id="安装Node-js和Express"><a href="#安装Node-js和Express" class="headerlink" title="安装Node.js和Express"></a>安装Node.js和Express</h2><p>首先，确保你已经安装了Node.js。然后使用npm安装Express框架：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">npm install express</span><br></pre></td></tr></table></figure><h2 id="创建Express应用"><a href="#创建Express应用" class="headerlink" title="创建Express应用"></a>创建Express应用</h2><p>创建一个基本的Express应用：</p><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">const</span> express = <span class="built_in">require</span>(<span class="string">'express'</span>);</span><br><span class="line"><span class="keyword">const</span> app = <span class="title function_">express</span>();</span><br><span class="line"><span class="keyword">const</span> port = <span class="number">3000</span>;</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">use</span>(express.<span class="title function_">json</span>());</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">get</span>(<span class="string">'/'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> res.<span class="title function_">send</span>(<span class="string">'Hello World!'</span>);</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">listen</span>(port, <span class="function">() =></span> {</span><br><span class="line"> <span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="string">`Server is running on port <span class="subst">${port}</span>`</span>);</span><br><span class="line">});</span><br></pre></td></tr></table></figure><h2 id="定义RESTful-API路由"><a href="#定义RESTful-API路由" class="headerlink" title="定义RESTful API路由"></a>定义RESTful API路由</h2><p>以下是一个简单的CRUD示例：</p><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">let</span> items = [];</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">post</span>(<span class="string">'/items'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> <span class="keyword">const</span> item = req.<span class="property">body</span>;</span><br><span class="line"> items.<span class="title function_">push</span>(item);</span><br><span class="line"> res.<span class="title function_">status</span>(<span class="number">201</span>).<span class="title function_">send</span>(item);</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">get</span>(<span class="string">'/items'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> res.<span class="title function_">send</span>(items);</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">get</span>(<span class="string">'/items/:id'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> <span class="keyword">const</span> item = items.<span class="title function_">find</span>(<span class="function"><span class="params">i</span> =></span> i.<span class="property">id</span> === <span class="built_in">parseInt</span>(req.<span class="property">params</span>.<span class="property">id</span>));</span><br><span class="line"> <span class="keyword">if</span> (!item) <span class="keyword">return</span> res.<span class="title function_">status</span>(<span class="number">404</span>).<span class="title function_">send</span>(<span class="string">'Item not found'</span>);</span><br><span class="line"> res.<span class="title function_">send</span>(item);</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">put</span>(<span class="string">'/items/:id'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> <span class="keyword">const</span> item = items.<span class="title function_">find</span>(<span class="function"><span class="params">i</span> =></span> i.<span class="property">id</span> === <span class="built_in">parseInt</span>(req.<span class="property">params</span>.<span class="property">id</span>));</span><br><span class="line"> <span class="keyword">if</span> (!item) <span class="keyword">return</span> res.<span class="title function_">status</span>(<span class="number">404</span>).<span class="title function_">send</span>(<span class="string">'Item not found'</span>);</span><br><span class="line"></span><br><span class="line"> item.<span class="property">name</span> = req.<span class="property">body</span>.<span class="property">name</span>;</span><br><span class="line"> res.<span class="title function_">send</span>(item);</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line">app.<span class="title function_">delete</span>(<span class="string">'/items/:id'</span>, <span class="function">(<span class="params">req, res</span>) =></span> {</span><br><span class="line"> <span class="keyword">const</span> itemIndex = items.<span class="title function_">findIndex</span>(<span class="function"><span class="params">i</span> =></span> i.<span class="property">id</span> === <span class="built_in">parseInt</span>(req.<span class="property">params</span>.<span class="property">id</span>));</span><br><span class="line"> <span class="keyword">if</span> (itemIndex === -<span class="number">1</span>) <span class="keyword">return</span> res.<span class="title function_">status</span>(<span class="number">404</span>).<span class="title function_">send</span>(<span class="string">'Item not found'</span>);</span><br><span class="line"></span><br><span class="line"> items.<span class="title function_">splice</span>(itemIndex, <span class="number">1</span>);</span><br><span class="line"> res.<span class="title function_">status</span>(<span class="number">204</span>).<span class="title function_">send</span>();</span><br><span class="line">});</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>使用Node.js和Express构建RESTful API非常简单且高效，这使得它成为构建后端服务的流行选择。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[使用Node.js构建RESTful API] --> B[安装Node.js和Express]</span><br><span class="line"> A --> C[创建Express应用]</span><br><span class="line"> A --> D[定义RESTful API路由]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>学习Go语言的基础知识</title>
<link href="/2025/03/23/article8/"/>
<url>/2025/03/23/article8/</url>
<content type="html"><![CDATA[<h1 id="学习Go语言的基础知识"><a href="#学习Go语言的基础知识" class="headerlink" title="学习Go语言的基础知识"></a>学习Go语言的基础知识</h1><h2 id="Go语言简介"><a href="#Go语言简介" class="headerlink" title="Go语言简介"></a>Go语言简介</h2><p>Go语言是由Google开发的一种静态类型、编译型编程语言，具有简单、高效和并发编程的特点。</p><h2 id="基本语法"><a href="#基本语法" class="headerlink" title="基本语法"></a>基本语法</h2><p>以下是一个简单的Go程序：</p><figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> main</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> <span class="string">"fmt"</span></span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">func</span> <span class="title">main</span><span class="params">()</span></span> {</span><br><span class="line"> fmt.Println(<span class="string">"Hello, World!"</span>)</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="数据类型"><a href="#数据类型" class="headerlink" title="数据类型"></a>数据类型</h2><p>Go语言支持多种数据类型，包括基本类型、复合类型和引用类型。</p><figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">var</span> a <span class="type">int</span> = <span class="number">10</span></span><br><span class="line"><span class="keyword">var</span> b <span class="type">float64</span> = <span class="number">3.14</span></span><br><span class="line"><span class="keyword">var</span> c <span class="type">string</span> = <span class="string">"Hello"</span></span><br><span class="line"><span class="keyword">var</span> d <span class="type">bool</span> = <span class="literal">true</span></span><br></pre></td></tr></table></figure><h2 id="控制结构"><a href="#控制结构" class="headerlink" title="控制结构"></a>控制结构</h2><p>Go语言提供了丰富的控制结构，包括条件语句、循环语句和选择语句。</p><figure class="highlight go"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">if</span> a > b {</span><br><span class="line"> fmt.Println(<span class="string">"a is greater than b"</span>)</span><br><span class="line">} <span class="keyword">else</span> {</span><br><span class="line"> fmt.Println(<span class="string">"a is not greater than b"</span>)</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">for</span> i := <span class="number">0</span>; i < <span class="number">10</span>; i++ {</span><br><span class="line"> fmt.Println(i)</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Go语言是一种功能强大的编程语言，适合用于构建高效和可扩展的应用程序。通过学习其基础知识，你可以快速上手并开始编写Go程序。</p><h2 id="思维导"><a href="#思维导" class="headerlink" title="思维导"></a>思维导</h2>]]></content>
</entry>
<entry>
<title>理解Kubernetes中的Pod</title>
<link href="/2025/03/23/article9/"/>
<url>/2025/03/23/article9/</url>
<content type="html"><![CDATA[<h1 id="理解Kubernetes中的Pod"><a href="#理解Kubernetes中的Pod" class="headerlink" title="理解Kubernetes中的Pod"></a>理解Kubernetes中的Pod</h1><h2 id="什么是Pod？"><a href="#什么是Pod？" class="headerlink" title="什么是Pod？"></a>什么是Pod？</h2><p>Pod是Kubernetes中最小的可部署单元，通常包含一个或多个容器，这些容器共享存储和网络资源。</p><h2 id="Pod的结构"><a href="#Pod的结构" class="headerlink" title="Pod的结构"></a>Pod的结构</h2><p>一个Pod由以下部分组成：</p><ol><li><strong>容器</strong>：Pod中的应用程序运行在容器中。</li><li><strong>存储卷</strong>：Pod中的容器可以共享存储卷，用于持久化数据。</li><li><strong>网络</strong>：Pod中的容器共享一个IP地址和端口空间。</li></ol><h2 id="创建Pod"><a href="#创建Pod" class="headerlink" title="创建Pod"></a>创建Pod</h2><p>使用YAML文件创建Pod的示例：</p><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="attr">apiVersion:</span> <span class="string">v1</span></span><br><span class="line"><span class="attr">kind:</span> <span class="string">Pod</span></span><br><span class="line"><span class="attr">metadata:</span></span><br><span class="line"> <span class="attr">name:</span> <span class="string">my-pod</span></span><br><span class="line"><span class="attr">spec:</span></span><br><span class="line"> <span class="attr">containers:</span></span><br><span class="line"> <span class="bullet">-</span> <span class="attr">name:</span> <span class="string">my-container</span></span><br><span class="line"> <span class="attr">image:</span> <span class="string">nginx</span></span><br><span class="line"> <span class="attr">ports:</span></span><br><span class="line"> <span class="bullet">-</span> <span class="attr">containerPort:</span> <span class="number">80</span></span><br></pre></td></tr></table></figure><p>应用Pod配置：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">kubectl apply -f my-pod.yaml</span><br></pre></td></tr></table></figure><h2 id="查看Pod状态"><a href="#查看Pod状态" class="headerlink" title="查看Pod状态"></a>查看Pod状态</h2><p>查看Pod的状态：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">kubectl get pods</span><br></pre></td></tr></table></figure><p>查看Pod的详细信息：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">kubectl describe pod my-pod</span><br></pre></td></tr></table></figure><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>Pod是Kubernetes中的核心概念，理解Pod的结构和使用方法是掌握Kubernetes的重要一步。通过Pod，开发者可以灵活地管理和编排容器化应用。</p><h2 id="思维导图"><a href="#思维导图" class="headerlink" title="思维导图"></a>思维导图</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">graph TD;</span><br><span class="line"> A[理解Kubernetes中的Pod] --> B[什么是Pod]</span><br><span class="line"> A --> C[Pod的结构]</span><br><span class="line"> A --> D[创建Pod]</span><br><span class="line"> A --> E[查看Pod状态]</span><br></pre></td></tr></table></figure>]]></content>
</entry>
<entry>
<title>免费的LinuxONE服务器</title>
<link href="/2025/03/10/%E6%80%8E%E6%A0%B7%E7%99%BD%E5%AB%96LinuxOne%E5%85%8D%E8%B4%B9%E6%9C%8D%E5%8A%A1%E5%99%A8/"/>
<url>/2025/03/10/%E6%80%8E%E6%A0%B7%E7%99%BD%E5%AB%96LinuxOne%E5%85%8D%E8%B4%B9%E6%9C%8D%E5%8A%A1%E5%99%A8/</url>
<content type="html"><![CDATA[<p>今天来教大家白嫖一个免费的服务器,<strong>他不用海外的信用卡,只需要用电子邮箱即可</strong>!</p><p><strong>声明：这是一台S390X架构的服务器,很多软件都无法兼容.</strong></p><p>只教怎么创建服务器,不教ssh和链接方法,自行搜索!</p><p>服务器详细信息:</p><p><strong>OS: Ubuntu 22.04.1 LTS s390x</strong></p><p><strong>CPU: 8561 (2) @ 5.200GHz</strong></p><p><strong>Memory: 4GB</strong></p><p><strong>诚意也是非常到位</strong></p><p>准备:一个电子邮箱</p><p>访问<a href="https://linuxone.cloud.marist.edu/">linuxone官网</a>.点击Register,然后按照图片内容填写.接着到邮件去激活.</p><p>点击Vistual Servers.点击Create,并按你的需要填写.然后享受这台服务器吧!</p>]]></content>
</entry>
<entry>
<title>Blogger国内访问方法</title>
<link href="/2025/03/10/Blogger%E5%9B%BD%E5%86%85%E8%AE%BF%E9%97%AE%E6%96%B9%E6%B3%95/"/>
<url>/2025/03/10/Blogger%E5%9B%BD%E5%86%85%E8%AE%BF%E9%97%AE%E6%96%B9%E6%B3%95/</url>
<content type="html"><![CDATA[<p>Blogger是一个非常有实力的免费博客平台,一贯保持无广告,不作恶的原则.它既<strong>免去了Hexo,Hugo麻烦的DEPLOY操作,也没有CSDN那样的广告</strong>.但是它在国内被墙了(来自东方长城的力量),因此我们可以绑定自定义域名来绕过防火墙.</p><p><del>(当然你可以选择是否开启广告)</del></p><p>你可以不用它提供的*.blogspot.com域名,绑定自定义域名.</p><p>下面,我将一步步教你怎么拥有自己的博客,而且在国内正常访问.</p><p>首先,访问<a href="//blogger.com">Blogger官网</a>,然后点击”新建博客”,使用Google账号登陆.</p><p>然后点击左上角,再点击新建博客.</p><p>输入你的网站显示的标题,点击”下一步”.</p><p>然后输入一个域名(Blogspot),再点击保存.</p><p>现在点击”查看博客”,就可以看到你的博客了,点击右上角新建博文写文章.</p><p>但是Blogger在国内被墙了,所以我们要绑定自定义域名.(以us.kg为例)</p><p>访问<a href="https://register.us.kg/">注册us.kg官网</a>,注册后,按照提示,进行KYC验证.</p><p>KYC验证通过后,访问<a href="https://register.us.kg/panel/register">获取域名</a><br>输入一个域名,点击check.</p><p>当看到这个页面时,不要关闭,也不要输入任何内容.</p><p>在<a href="https://dash.cloudflare.com/">Cloudflare</a>注册帐号,然后点击”添加域”,输入你的域名,点击”继续”.</p><p>选择”Free”计划,继续.</p><p>当看到这个页面时,不要关闭,也不要输入任何内容.</p><p>回到Blogger点击”设置”,找到”发布”,再点击”自定义域名”.</p><p>输入网址后,点击”保存”,不要关闭.(<strong>注意：要在网站前加”www.</strong>“)</p><p>回到Cloudflare,点击”添加记录”,类型选择”CNAME”,名称填写”www”,目标填写”ghs.google.com”.</p><p><strong>注意：一定要把代理关掉,否则无法验证！！！</strong></p><p>再添加一个(验证CNAME),名称填第二个CNAME所显示的名称,目标网域填第二个.</p><p>然后点击继续.</p><p>滑到下面”更新名称服务器”,复制两个<em>Cloudflare名称服务器.</em></p><p>回到DomainRegistration这个页面,把这两个Cloudflare名称服务器粘贴进去,然后点击Register.</p><p>显示success后关闭.</p><p>回到Blogger再点击一次保存,即可保存.</p><p>把这张图里的3个开关全部打开,然后等待15分钟后就可以了.</p><p>现在,你的博客就可以在国内访问了.</p><p>感谢观看！</p>]]></content>
</entry>
<entry>
<title>Minecraft更新公告</title>
<link href="/2025/03/09/%E6%9B%B4%E6%96%B0%E5%85%AC%E5%91%8A/"/>
<url>/2025/03/09/%E6%9B%B4%E6%96%B0%E5%85%AC%E5%91%8A/</url>
<content type="html"><![CDATA[<p><strong>Minecraft已完成全面汉化!</strong><br>新增了<strong>演示模式(Demo Mode)</strong>,以丰富游戏体验.<br>内置PBR光影也已经升级.</p>]]></content>
</entry>
<entry>
<title>生产环境Docker部署的7个优化技巧</title>
<link href="/2024/03/22/%E7%94%9F%E4%BA%A7%E7%8E%AF%E5%A2%83Docker%E9%83%A8%E7%BD%B2%E7%9A%847%E4%B8%AA%E4%BC%98%E5%8C%96%E6%8A%80%E5%B7%A7/"/>
<url>/2024/03/22/%E7%94%9F%E4%BA%A7%E7%8E%AF%E5%A2%83Docker%E9%83%A8%E7%BD%B2%E7%9A%847%E4%B8%AA%E4%BC%98%E5%8C%96%E6%8A%80%E5%B7%A7/</url>
<content type="html"><![CDATA[<hr><h2 id="1-镜像瘦身三剑客"><a href="#1-镜像瘦身三剑客" class="headerlink" title="1. 镜像瘦身三剑客"></a>1. 镜像瘦身三剑客</h2><h3 id="多阶段构建实战"><a href="#多阶段构建实战" class="headerlink" title="多阶段构建实战"></a>多阶段构建实战</h3><figure class="highlight dockerfile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 构建阶段</span></span><br><span class="line"><span class="keyword">FROM</span> golang:<span class="number">1.20</span> AS builder</span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /app</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> . .</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> CGO_ENABLED=0 go build -o myapp .</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 运行阶段</span></span><br><span class="line"><span class="keyword">FROM</span> alpine:<span class="number">3.18</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> apk --no-cache add ca-certificates</span></span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /root/</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> --from=builder /app/myapp .</span></span><br><span class="line"><span class="keyword">CMD</span><span class="language-bash"> [<span class="string">"./myapp"</span>]</span></span><br></pre></td></tr></table></figure><h3 id="基础镜像对比"><a href="#基础镜像对比" class="headerlink" title="基础镜像对比"></a>基础镜像对比</h3><table><thead><tr><th>镜像类型</th><th>大小</th><th>特点</th></tr></thead><tbody><tr><td>ubuntu:22.04</td><td>72.8MB</td><td>完整系统工具</td></tr><tr><td>debian:12</td><td>54.3MB</td><td>精简版基础系统</td></tr><tr><td>alpine:3.18</td><td>5.7MB</td><td>最小化musl libc环境</td></tr><tr><td>scratch</td><td>0MB</td><td>空镜像（需静态编译）</td></tr></tbody></table><hr><h2 id="2-安全加固四要素"><a href="#2-安全加固四要素" class="headerlink" title="2. 安全加固四要素"></a>2. 安全加固四要素</h2><h3 id="安全配置示例"><a href="#安全配置示例" class="headerlink" title="安全配置示例"></a>安全配置示例</h3><figure class="highlight dockerfile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">FROM</span> alpine:<span class="number">3.18</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 创建非root用户</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> addgroup -S appgroup && adduser -S appuser -G appgroup</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 设置只读文件系统</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> <span class="built_in">mkdir</span> -p /app/data && <span class="built_in">chown</span> appuser:appgroup /app/data</span></span><br><span class="line"><span class="keyword">VOLUME</span><span class="language-bash"> /app/data</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">USER</span> appuser</span><br><span class="line"></span><br><span class="line"><span class="comment"># 移除默认能力</span></span><br><span class="line">docker <span class="keyword">run</span><span class="language-bash"> --cap-drop=ALL --cap-add=NET_BIND_SERVICE ...</span></span><br></pre></td></tr></table></figure><h3 id="安全扫描工具"><a href="#安全扫描工具" class="headerlink" title="安全扫描工具"></a>安全扫描工具</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 使用Trivy扫描镜像漏洞</span></span><br><span class="line">trivy image myapp:1.0</span><br><span class="line"></span><br><span class="line"><span class="comment"># 输出示例</span></span><br><span class="line">myapp:1.0 (alpine 3.18.3)</span><br><span class="line">=========================</span><br><span class="line">Total: 2 (HIGH: 2)</span><br><span class="line"></span><br><span class="line">+---------+------------------+----------+-------------------+---------------+---------------------------------------+</span><br><span class="line">| LIBRARY | VULNERABILITY ID | SEVERITY | INSTALLED VERSION | FIXED VERSION | TITLE |</span><br><span class="line">+---------+------------------+----------+-------------------+---------------+---------------------------------------+</span><br><span class="line">| openssl | CVE-2023-3817 | HIGH | 3.1.1-r1 | 3.1.2-r0 | Excessive <span class="keyword">time</span> spent checking invalid |</span><br><span class="line">| | | | | | RSA public keys <span class="keyword">in</span> X.509 certificates</span><br></pre></td></tr></table></figure><hr><h2 id="3-资源限制黄金法则"><a href="#3-资源限制黄金法则" class="headerlink" title="3. 资源限制黄金法则"></a>3. 资源限制黄金法则</h2><h3 id="容器资源配额"><a href="#容器资源配额" class="headerlink" title="容器资源配额"></a>容器资源配额</h3><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># docker-compose.yml示例</span></span><br><span class="line"><span class="attr">services:</span></span><br><span class="line"> <span class="attr">web:</span></span><br><span class="line"> <span class="attr">image:</span> <span class="string">nginx:alpine</span></span><br><span class="line"> <span class="attr">deploy:</span></span><br><span class="line"> <span class="attr">resources:</span></span><br><span class="line"> <span class="attr">limits:</span></span><br><span class="line"> <span class="attr">cpus:</span> <span class="string">'0.5'</span></span><br><span class="line"> <span class="attr">memory:</span> <span class="string">512M</span></span><br><span class="line"> <span class="attr">reservations:</span></span><br><span class="line"> <span class="attr">memory:</span> <span class="string">256M</span></span><br><span class="line"> <span class="attr">ports:</span></span><br><span class="line"> <span class="bullet">-</span> <span class="string">"80:80"</span></span><br></pre></td></tr></table></figure><h3 id="内存限制策略"><a href="#内存限制策略" class="headerlink" title="内存限制策略"></a>内存限制策略</h3><table><thead><tr><th>参数</th><th>作用</th><th>生产建议值</th></tr></thead><tbody><tr><td>–memory</td><td>硬性内存限制</td><td>物理内存的80%</td></tr><tr><td>–memory-swap</td><td>内存+交换分区总限制</td><td>建议设置为0</td></tr><tr><td>–memory-reservation</td><td>内存软限制（触发告警）</td><td>物理内存的70%</td></tr><tr><td>–oom-kill-disable</td><td>禁止OOM Killer</td><td>生产环境禁用</td></tr></tbody></table><hr><h2 id="4-构建缓存优化"><a href="#4-构建缓存优化" class="headerlink" title="4. 构建缓存优化"></a>4. 构建缓存优化</h2><h3 id="Dockerfile优化前后对比"><a href="#Dockerfile优化前后对比" class="headerlink" title="Dockerfile优化前后对比"></a>Dockerfile优化前后对比</h3><figure class="highlight dockerfile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 优化前</span></span><br><span class="line"><span class="keyword">FROM</span> node:<span class="number">18</span></span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /app</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> . .</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> npm install</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> npm run build</span></span><br><span class="line"><span class="keyword">CMD</span><span class="language-bash"> [<span class="string">"node"</span>, <span class="string">"dist/main.js"</span>]</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 优化后</span></span><br><span class="line"><span class="keyword">FROM</span> node:<span class="number">18</span> AS builder</span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /app</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> package*.json ./</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> npm ci --production</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> src ./src</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> tsconfig.json ./</span></span><br><span class="line"><span class="keyword">RUN</span><span class="language-bash"> npm run build</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">FROM</span> node:<span class="number">18</span>-alpine</span><br><span class="line"><span class="keyword">WORKDIR</span><span class="language-bash"> /app</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> --from=builder /app/package*.json ./</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> --from=builder /app/node_modules ./node_modules</span></span><br><span class="line"><span class="keyword">COPY</span><span class="language-bash"> --from=builder /app/dist ./dist</span></span><br><span class="line"><span class="keyword">CMD</span><span class="language-bash"> [<span class="string">"node"</span>, <span class="string">"dist/main.js"</span>]</span></span><br></pre></td></tr></table></figure><h3 id="构建时间对比"><a href="#构建时间对比" class="headerlink" title="构建时间对比"></a>构建时间对比</h3><table><thead><tr><th>阶段</th><th>优化前</th><th>优化后</th><th>提升幅度</th></tr></thead><tbody><tr><td>依赖安装</td><td>45s</td><td>18s</td><td>60%</td></tr><tr><td>构建过程</td><td>32s</td><td>28s</td><td>12.5%</td></tr><tr><td>总镜像大小</td><td>1.2GB</td><td>256MB</td><td>78%</td></tr></tbody></table><hr><h2 id="5-高效日志管理"><a href="#5-高效日志管理" class="headerlink" title="5. 高效日志管理"></a>5. 高效日志管理</h2><h3 id="日志驱动配置"><a href="#日志驱动配置" class="headerlink" title="日志驱动配置"></a>日志驱动配置</h3><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"log-driver"</span><span class="punctuation">:</span> <span class="string">"json-file"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"log-opts"</span><span class="punctuation">:</span> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"max-size"</span><span class="punctuation">:</span> <span class="string">"10m"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"max-file"</span><span class="punctuation">:</span> <span class="string">"5"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"compress"</span><span class="punctuation">:</span> <span class="string">"true"</span></span><br><span class="line"> <span class="punctuation">}</span></span><br><span class="line"><span class="punctuation">}</span></span><br></pre></td></tr></table></figure><h3 id="日志收集架构"><a href="#日志收集架构" class="headerlink" title="日志收集架构"></a>日志收集架构</h3><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">[容器] --> [Fluentd] --> [Elasticsearch]</span><br><span class="line"> │</span><br><span class="line"> └─>[AWS CloudWatch]</span><br></pre></td></tr></table></figure><hr><h2 id="6-健康检查策略"><a href="#6-健康检查策略" class="headerlink" title="6. 健康检查策略"></a>6. 健康检查策略</h2><h3 id="探针配置示例"><a href="#探针配置示例" class="headerlink" title="探针配置示例"></a>探针配置示例</h3><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="attr">healthcheck:</span></span><br><span class="line"> <span class="attr">test:</span> [<span class="string">"CMD-SHELL"</span>, <span class="string">"curl -f http://localhost:8080/health || exit 1"</span>]</span><br><span class="line"> <span class="attr">interval:</span> <span class="string">30s</span></span><br><span class="line"> <span class="attr">timeout:</span> <span class="string">5s</span></span><br><span class="line"> <span class="attr">retries:</span> <span class="number">3</span></span><br><span class="line"> <span class="attr">start_period:</span> <span class="string">10s</span></span><br></pre></td></tr></table></figure><h3 id="探针类型对比"><a href="#探针类型对比" class="headerlink" title="探针类型对比"></a>探针类型对比</h3><table><thead><tr><th>类型</th><th>检查目标</th><th>应用场景</th></tr></thead><tbody><tr><td>HTTP探针</td><td>指定端口的HTTP状态码</td><td>Web服务</td></tr><tr><td>TCP探针</td><td>端口是否开放</td><td>数据库/中间件</td></tr><tr><td>命令探针</td><td>执行命令的返回值</td><td>复杂状态检查</td></tr></tbody></table><hr><h2 id="7-镜像仓库优化"><a href="#7-镜像仓库优化" class="headerlink" title="7. 镜像仓库优化"></a>7. 镜像仓库优化</h2><h3 id="镜像标签策略"><a href="#镜像标签策略" class="headerlink" title="镜像标签策略"></a>镜像标签策略</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 推送多架构镜像</span></span><br><span class="line">docker buildx build --platform linux/amd64,linux/arm64 -t myrepo/myapp:1.0 .</span><br><span class="line"></span><br><span class="line"><span class="comment"># 标记为最新版</span></span><br><span class="line">docker tag myrepo/myapp:1.0 myrepo/myapp:latest</span><br></pre></td></tr></table></figure><h3 id="镜像清理脚本"><a href="#镜像清理脚本" class="headerlink" title="镜像清理脚本"></a>镜像清理脚本</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#!/bin/bash</span></span><br><span class="line"><span class="comment"># 保留最近3个标签</span></span><br><span class="line">docker images | grep myapp | awk <span class="string">'{print $3}'</span> | <span class="built_in">tail</span> -n +4 | xargs docker rmi -f</span><br></pre></td></tr></table></figure><hr><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>通过实施这7个维度的优化策略，可使生产环境Docker容器在安全性、性能和可维护性方面达到企业级标准。建议结合CI/CD流水线实现自动化优化，并定期进行镜像漏洞扫描。</p><blockquote><p><strong>延伸阅读</strong>： </p><ul><li>Docker官方最佳实践文档 </li><li>《Kubernetes生产化实践指南》 </li><li>CIS Docker安全基准</li></ul></blockquote>]]></content>
</entry>
<entry>
<title>React Hooks进阶：10个高效开发技巧</title>
<link href="/2024/03/21/ReactHooks%E8%BF%9B%E9%98%B610%E4%B8%AA%E9%AB%98%E6%95%88%E5%BC%80%E5%8F%91%E6%8A%80%E5%B7%A7/"/>
<url>/2024/03/21/ReactHooks%E8%BF%9B%E9%98%B610%E4%B8%AA%E9%AB%98%E6%95%88%E5%BC%80%E5%8F%91%E6%8A%80%E5%B7%A7/</url>
<content type="html"><![CDATA[<h2 id="1-精准控制useEffect依赖"><a href="#1-精准控制useEffect依赖" class="headerlink" title="1. 精准控制useEffect依赖"></a>1. 精准控制useEffect依赖</h2><h3 id="黄金法则"><a href="#黄金法则" class="headerlink" title="黄金法则"></a>黄金法则</h3><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 错误示例：缺少依赖</span></span><br><span class="line"><span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="title function_">fetchData</span>(params.<span class="property">id</span>);</span><br><span class="line">}, []);</span><br><span class="line"></span><br><span class="line"><span class="comment">// 正确示例：完整声明依赖</span></span><br><span class="line"><span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="keyword">const</span> controller = <span class="keyword">new</span> <span class="title class_">AbortController</span>();</span><br><span class="line"> <span class="title function_">fetchData</span>(params.<span class="property">id</span>, { <span class="attr">signal</span>: controller.<span class="property">signal</span> });</span><br><span class="line"> <span class="keyword">return</span> <span class="function">() =></span> controller.<span class="title function_">abort</span>();</span><br><span class="line">}, [params.<span class="property">id</span>]); <span class="comment">// ✅ 明确声明所有依赖项</span></span><br></pre></td></tr></table></figure><h3 id="依赖管理策略"><a href="#依赖管理策略" class="headerlink" title="依赖管理策略"></a>依赖管理策略</h3><table><thead><tr><th>场景</th><th>解决方案</th><th>工具支持</th></tr></thead><tbody><tr><td>频繁变化的依赖</td><td>使用useReducer</td><td>useReducer+dispatch</td></tr><tr><td>对象/数组依赖</td><td>深度比较或拆解基本类型</td><td>lodash.isEqual</td></tr><tr><td>函数依赖</td><td>useCallback包裹</td><td>eslint-plugin-react-hooks</td></tr></tbody></table><hr><h2 id="2-自定义Hook工程化实践"><a href="#2-自定义Hook工程化实践" class="headerlink" title="2. 自定义Hook工程化实践"></a>2. 自定义Hook工程化实践</h2><h3 id="数据请求Hook示例"><a href="#数据请求Hook示例" class="headerlink" title="数据请求Hook示例"></a>数据请求Hook示例</h3><figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">function</span> useFetch<T>(<span class="attr">url</span>: <span class="built_in">string</span>, <span class="attr">options</span>?: <span class="title class_">RequestInit</span>) {</span><br><span class="line"> <span class="keyword">const</span> [data, setData] = useState<T | <span class="literal">null</span>>(<span class="literal">null</span>);</span><br><span class="line"> <span class="keyword">const</span> [error, setError] = useState<<span class="title class_">Error</span> | <span class="literal">null</span>>(<span class="literal">null</span>);</span><br><span class="line"> <span class="keyword">const</span> [loading, setLoading] = <span class="title function_">useState</span>(<span class="literal">true</span>);</span><br><span class="line"></span><br><span class="line"> <span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="keyword">const</span> abortController = <span class="keyword">new</span> <span class="title class_">AbortController</span>();</span><br><span class="line"> </span><br><span class="line"> <span class="keyword">const</span> <span class="title function_">fetchData</span> = <span class="keyword">async</span> (<span class="params"></span>) => {</span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> <span class="keyword">const</span> response = <span class="keyword">await</span> <span class="title function_">fetch</span>(url, {</span><br><span class="line"> ...options,</span><br><span class="line"> <span class="attr">signal</span>: abortController.<span class="property">signal</span></span><br><span class="line"> });</span><br><span class="line"> <span class="keyword">const</span> json = <span class="keyword">await</span> response.<span class="title function_">json</span>();</span><br><span class="line"> <span class="title function_">setData</span>(json);</span><br><span class="line"> } <span class="keyword">catch</span> (err) {</span><br><span class="line"> <span class="keyword">if</span> (!abortController.<span class="property">signal</span>.<span class="property">aborted</span>) {</span><br><span class="line"> <span class="title function_">setError</span>(err <span class="keyword">as</span> <span class="title class_">Error</span>);</span><br><span class="line"> }</span><br><span class="line"> } <span class="keyword">finally</span> {</span><br><span class="line"> <span class="title function_">setLoading</span>(<span class="literal">false</span>);</span><br><span class="line"> }</span><br><span class="line"> };</span><br><span class="line"></span><br><span class="line"> <span class="title function_">fetchData</span>();</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> <span class="function">() =></span> abortController.<span class="title function_">abort</span>();</span><br><span class="line"> }, [url, options]);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> { data, error, loading };</span><br><span class="line">}</span><br></pre></td></tr></table></figure><hr><h2 id="3-性能优化三重奏"><a href="#3-性能优化三重奏" class="headerlink" title="3. 性能优化三重奏"></a>3. 性能优化三重奏</h2><h3 id="优化策略对比"><a href="#优化策略对比" class="headerlink" title="优化策略对比"></a>优化策略对比</h3><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 未优化组件：每次渲染都重新计算</span></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">List</span>(<span class="params">{ items }</span>) {</span><br><span class="line"> <span class="keyword">const</span> filtered = items.<span class="title function_">filter</span>(...); <span class="comment">// 🚫 重复计算</span></span><br><span class="line"> </span><br><span class="line"> <span class="keyword">return</span> <span class="language-xml"><span class="tag"><<span class="name">div</span>></span>{filtered.map(...)}<span class="tag"></<span class="name">div</span>></span></span>;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="comment">// 优化后组件：使用useMemo缓存</span></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">OptimizedList</span>(<span class="params">{ items }</span>) {</span><br><span class="line"> <span class="keyword">const</span> filtered = <span class="title function_">useMemo</span>(</span><br><span class="line"> <span class="function">() =></span> items.<span class="title function_">filter</span>(...), </span><br><span class="line"> [items] <span class="comment">// ✅ 依赖项变更时才重新计算</span></span><br><span class="line"> );</span><br><span class="line"> </span><br><span class="line"> <span class="keyword">return</span> <span class="language-xml"><span class="tag"><<span class="name">div</span>></span>{filtered.map(...)}<span class="tag"></<span class="name">div</span>></span></span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure><h3 id="渲染性能检测"><a href="#渲染性能检测" class="headerlink" title="渲染性能检测"></a>渲染性能检测</h3><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 使用React DevTools的Profiler组件</span></span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">Profiler</span> } <span class="keyword">from</span> <span class="string">'react'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">const</span> <span class="title function_">onRender</span> = (<span class="params">id, phase, actualDuration</span>) => {</span><br><span class="line"> <span class="variable language_">console</span>.<span class="title function_">log</span>(<span class="string">`<span class="subst">${id}</span> <span class="subst">${phase}</span>耗时: <span class="subst">${actualDuration}</span>ms`</span>);</span><br><span class="line">};</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">App</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="keyword">return</span> (</span><br><span class="line"> <span class="language-xml"><span class="tag"><<span class="name">Profiler</span> <span class="attr">id</span>=<span class="string">"Navigation"</span> <span class="attr">onRender</span>=<span class="string">{onRender}</span>></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"><<span class="name">Navigation</span> /></span></span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">Profiler</span>></span></span></span><br><span class="line"> );</span><br><span class="line">}</span><br></pre></td></tr></table></figure><hr><h2 id="4-状态提升与上下文共享"><a href="#4-状态提升与上下文共享" class="headerlink" title="4. 状态提升与上下文共享"></a>4. 状态提升与上下文共享</h2><h3 id="Context优化模式"><a href="#Context优化模式" class="headerlink" title="Context优化模式"></a>Context优化模式</h3><figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 创建优化的Context</span></span><br><span class="line"><span class="keyword">const</span> <span class="title class_">UserContext</span> = <span class="title class_">React</span>.<span class="property">createContext</span><{</span><br><span class="line"> <span class="attr">user</span>: <span class="title class_">User</span>;</span><br><span class="line"> <span class="attr">update</span>: <span class="function">(<span class="params"><span class="attr">user</span>: <span class="title class_">User</span></span>) =></span> <span class="built_in">void</span>;</span><br><span class="line">}>(<span class="literal">null</span>!);</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">UserProvider</span>(<span class="params">{ children }</span>) {</span><br><span class="line"> <span class="keyword">const</span> [user, setUser] = <span class="title function_">useState</span>(initialUser);</span><br><span class="line"> </span><br><span class="line"> <span class="comment">// 使用useCallback避免Provider值不必要变化</span></span><br><span class="line"> <span class="keyword">const</span> updateUser = <span class="title function_">useCallback</span>(<span class="function">(<span class="params"><span class="attr">newUser</span>: <span class="title class_">User</span></span>) =></span> {</span><br><span class="line"> <span class="title function_">setUser</span>(<span class="function"><span class="params">prev</span> =></span> ({ ...prev, ...newUser }));</span><br><span class="line"> }, []);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">const</span> value = <span class="title function_">useMemo</span>(</span><br><span class="line"> <span class="function">() =></span> ({ user, <span class="attr">update</span>: updateUser }),</span><br><span class="line"> [user, updateUser]</span><br><span class="line"> );</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> (</span><br><span class="line"> <span class="language-xml"><span class="tag"><<span class="name">UserContext.Provider</span> <span class="attr">value</span>=<span class="string">{value}</span>></span></span></span><br><span class="line"><span class="language-xml"> {children}</span></span><br><span class="line"><span class="language-xml"> <span class="tag"></<span class="name">UserContext.Provider</span>></span></span></span><br><span class="line"> );</span><br><span class="line">}</span><br></pre></td></tr></table></figure><hr><h2 id="5-复杂状态管理方案"><a href="#5-复杂状态管理方案" class="headerlink" title="5. 复杂状态管理方案"></a>5. 复杂状态管理方案</h2><h3 id="状态机实现示例"><a href="#状态机实现示例" class="headerlink" title="状态机实现示例"></a>状态机实现示例</h3><figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> { useReducer } <span class="keyword">from</span> <span class="string">'react'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">const</span> initialState = {</span><br><span class="line"> <span class="attr">status</span>: <span class="string">'idle'</span>,</span><br><span class="line"> <span class="attr">data</span>: <span class="literal">null</span>,</span><br><span class="line"> <span class="attr">error</span>: <span class="literal">null</span></span><br><span class="line">};</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">fetchReducer</span>(<span class="params">state, action</span>) {</span><br><span class="line"> <span class="keyword">switch</span> (action.<span class="property">type</span>) {</span><br><span class="line"> <span class="keyword">case</span> <span class="string">'FETCH_START'</span>:</span><br><span class="line"> <span class="keyword">return</span> { ...state, <span class="attr">status</span>: <span class="string">'pending'</span> };</span><br><span class="line"> <span class="keyword">case</span> <span class="string">'FETCH_SUCCESS'</span>:</span><br><span class="line"> <span class="keyword">return</span> { <span class="attr">status</span>: <span class="string">'resolved'</span>, <span class="attr">data</span>: action.<span class="property">payload</span>, <span class="attr">error</span>: <span class="literal">null</span> };</span><br><span class="line"> <span class="keyword">case</span> <span class="string">'FETCH_FAILURE'</span>:</span><br><span class="line"> <span class="keyword">return</span> { <span class="attr">status</span>: <span class="string">'rejected'</span>, <span class="attr">data</span>: <span class="literal">null</span>, <span class="attr">error</span>: action.<span class="property">error</span> };</span><br><span class="line"> <span class="attr">default</span>:</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> <span class="title class_">Error</span>();</span><br><span class="line"> }</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">function</span> <span class="title function_">useFetchMachine</span>(<span class="params">url</span>) {</span><br><span class="line"> <span class="keyword">const</span> [state, dispatch] = <span class="title function_">useReducer</span>(fetchReducer, initialState);</span><br><span class="line"></span><br><span class="line"> <span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="title function_">dispatch</span>({ <span class="attr">type</span>: <span class="string">'FETCH_START'</span> });</span><br><span class="line"> </span><br><span class="line"> <span class="title function_">fetch</span>(url)</span><br><span class="line"> .<span class="title function_">then</span>(<span class="function"><span class="params">res</span> =></span> res.<span class="title function_">json</span>())</span><br><span class="line"> .<span class="title function_">then</span>(<span class="function"><span class="params">data</span> =></span> <span class="title function_">dispatch</span>({ <span class="attr">type</span>: <span class="string">'FETCH_SUCCESS'</span>, <span class="attr">payload</span>: data }))</span><br><span class="line"> .<span class="title function_">catch</span>(<span class="function"><span class="params">error</span> =></span> <span class="title function_">dispatch</span>({ <span class="attr">type</span>: <span class="string">'FETCH_FAILURE'</span>, error }));</span><br><span class="line"> }, [url]);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> state;</span><br><span class="line">}</span><br></pre></td></tr></table></figure><hr><h2 id="进阶技巧汇总"><a href="#进阶技巧汇总" class="headerlink" title="进阶技巧汇总"></a>进阶技巧汇总</h2><ol><li><strong>依赖数组自动化</strong>：使用<a href="https://www.npmjs.com/package/eslint-plugin-react-hooks">eslint-plugin-react-hooks</a>自动检测依赖缺失</li><li><strong>Hook组合模式</strong>：将多个基础Hook组合成复合Hook<figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">function</span> <span class="title function_">useWindowSize</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="keyword">const</span> [size, setSize] = <span class="title function_">useState</span>({ <span class="attr">width</span>: <span class="number">0</span>, <span class="attr">height</span>: <span class="number">0</span> });</span><br><span class="line"> </span><br><span class="line"> <span class="title function_">useEffect</span>(<span class="function">() =></span> {</span><br><span class="line"> <span class="keyword">const</span> <span class="title function_">handler</span> = (<span class="params"></span>) => <span class="title function_">setSize</span>({</span><br><span class="line"> <span class="attr">width</span>: <span class="variable language_">window</span>.<span class="property">innerWidth</span>,</span><br><span class="line"> <span class="attr">height</span>: <span class="variable language_">window</span>.<span class="property">innerHeight</span></span><br><span class="line"> });</span><br><span class="line"> </span><br><span class="line"> <span class="variable language_">window</span>.<span class="title function_">addEventListener</span>(<span class="string">'resize'</span>, handler);</span><br><span class="line"> <span class="keyword">return</span> <span class="function">() =></span> <span class="variable language_">window</span>.<span class="title function_">removeEventListener</span>(<span class="string">'resize'</span>, handler);</span><br><span class="line"> }, []);</span><br><span class="line"> </span><br><span class="line"> <span class="keyword">return</span> size;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></li><li><strong>调试技巧</strong>：使用<a href="https://github.com/welldone-software/why-did-you-render">useWhyDidYouUpdate</a>检测不必要的渲染</li></ol><hr><h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><p>通过合理运用这些进阶技巧，开发者可以显著提升React应用的性能和可维护性。建议结合TypeScript类型系统，并持续关注React 19中即将推出的<a href="https://github.com/reactjs/rfcs/pull/220">use优化</a>等新特性。</p><blockquote><p><strong>扩展阅读</strong>： </p><ul><li>React官方Hooks API参考 </li><li>《Hooks in Depth》视频课程 </li><li>React Query状态管理库</li></ul></blockquote>]]></content>
</entry>
<entry>
<title>微服务架构中的六种核心设计模式</title>
<link href="/2024/03/20/%E5%BE%AE%E6%9C%8D%E5%8A%A1%E6%9E%B6%E6%9E%84%E4%B8%AD%E7%9A%84%E5%85%AD%E7%A7%8D%E6%A0%B8%E5%BF%83%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F/"/>
<url>/2024/03/20/%E5%BE%AE%E6%9C%8D%E5%8A%A1%E6%9E%B6%E6%9E%84%E4%B8%AD%E7%9A%84%E5%85%AD%E7%A7%8D%E6%A0%B8%E5%BF%83%E8%AE%BE%E8%AE%A1%E6%A8%A1%E5%BC%8F/</url>
<content type="html"><![CDATA[<h2 id="前言"><a href="#前言" class="headerlink" title="前言"></a>前言</h2><p>在数字化转型浪潮中，微服务架构已成为构建复杂系统的首选方案。本文将深入解析六大核心设计模式，通过实际代码示例和架构图，展示如何构建高可用、可扩展的分布式系统。</p><hr><h2 id="服务发现模式"><a href="#服务发现模式" class="headerlink" title="服务发现模式"></a>服务发现模式</h2><p>服务发现模式是微服务架构中通信层的核心设计模式之一。它通过动态实例管理和健康检查机制，确保服务能够被可靠地发现和调用。</p><h3 id="动态实例管理"><a href="#动态实例管理" class="headerlink" title="动态实例管理"></a>动态实例管理</h3><p>在微服务架构中，服务实例可能会动态增加或减少。服务发现模式通过注册中心（如 Eureka、Consul 或 Zookeeper）记录所有可用的服务实例，并实时更新其状态。</p><h3 id="健康检查机制"><a href="#健康检查机制" class="headerlink" title="健康检查机制"></a>健康检查机制</h3><p>健康检查机制确保只有健康的服务实例能够被调用。注册中心会定期检查服务实例的健康状况，并将不可用的实例从注册表中移除。</p><h3 id="客户端-服务端发现"><a href="#客户端-服务端发现" class="headerlink" title="客户端/服务端发现"></a>客户端/服务端发现</h3><ul><li><strong>客户端发现</strong>：客户端直接查询注册中心获取服务实例列表，并通过负载均衡策略选择目标实例。</li><li><strong>服务端发现</strong>：客户端请求被代理到服务端，服务端通过注册中心找到目标实例并转发请求。</li></ul><hr><h2 id="API网关模式"><a href="#API网关模式" class="headerlink" title="API网关模式"></a>API网关模式</h2><p>API 网关模式为微服务架构提供了一个统一的入口，简化了客户端与服务之间的交互。</p><h3 id="统一入口"><a href="#统一入口" class="headerlink" title="统一入口"></a>统一入口</h3><p>API 网关充当所有客户端请求的入口，屏蔽了后端服务的复杂性。它可以路由请求到不同的服务，并聚合多个服务的响应。</p><h3 id="安全防护"><a href="#安全防护" class="headerlink" title="安全防护"></a>安全防护</h3><p>API 网关可以实现身份验证、授权和数据加密等安全功能，保护后端服务免受恶意攻击。</p><h3 id="流量控制"><a href="#流量控制" class="headerlink" title="流量控制"></a>流量控制</h3><p>通过限流、熔断和负载均衡等机制，API 网关可以有效管理流量，防止服务过载。</p><hr><h2 id="断路器模式"><a href="#断路器模式" class="headerlink" title="断路器模式"></a>断路器模式</h2><p>断路器模式是容错层的重要设计模式，用于隔离故障并提高系统的稳定性。</p><h3 id="故障隔离"><a href="#故障隔离" class="headerlink" title="故障隔离"></a>故障隔离</h3><p>当某个服务出现故障时，断路器会阻止请求继续发送到该服务，从而避免故障扩散。</p><h3 id="自动恢复"><a href="#自动恢复" class="headerlink" title="自动恢复"></a>自动恢复</h3><p>断路器会定期尝试恢复连接，当目标服务恢复正常时，断路器会重新允许请求通过。</p><h3 id="降级策略"><a href="#降级策略" class="headerlink" title="降级策略"></a>降级策略</h3><p>在服务不可用时，断路器可以返回默认值或执行备用逻辑，确保系统的基本功能可用。</p><hr><h2 id="Saga事务模式"><a href="#Saga事务模式" class="headerlink" title="Saga事务模式"></a>Saga事务模式</h2><p>Saga 事务模式通过分布式事务管理，确保微服务之间的数据一致性。</p><h3 id="补偿事务"><a href="#补偿事务" class="headerlink" title="补偿事务"></a>补偿事务</h3><p>Saga 模式将事务拆分为一系列小的本地事务，每个事务都有对应的补偿操作，用于回滚失败的操作。</p><h3 id="编排式-协同式"><a href="#编排式-协同式" class="headerlink" title="编排式/协同式"></a>编排式/协同式</h3><ul><li><strong>编排式</strong>：由中央控制器负责管理事务的执行顺序。</li><li><strong>协同式</strong>：每个服务通过事件驱动的方式协同完成事务。</li></ul><h3 id="最终一致性"><a href="#最终一致性" class="headerlink" title="最终一致性"></a>最终一致性</h3><p>Saga 模式通过异步操作和补偿机制，确保系统最终达到一致性，而非强一致性。</p><hr><h2 id="事件溯源模式"><a href="#事件溯源模式" class="headerlink" title="事件溯源模式"></a>事件溯源模式</h2><p>事件溯源模式通过记录系统中的所有事件，提供了数据层的强大支持。</p><h3 id="事件存储"><a href="#事件存储" class="headerlink" title="事件存储"></a>事件存储</h3><p>所有的状态变化都以事件的形式存储在事件日志中，确保数据的完整性和可追溯性。</p><h3 id="状态重建"><a href="#状态重建" class="headerlink" title="状态重建"></a>状态重建</h3><p>通过回放事件日志，可以在任何时间点重建系统的状态，方便调试和审计。</p><h3 id="CQRS架构"><a href="#CQRS架构" class="headerlink" title="CQRS架构"></a>CQRS架构</h3><p>事件溯源模式通常与 CQRS（命令查询职责分离）架构结合使用，将写操作和读操作分离，提高系统性能。</p><hr><h2 id="边车模式"><a href="#边车模式" class="headerlink" title="边车模式"></a>边车模式</h2><p>边车模式是基础设施层的重要设计模式，通过附加的边车进程为主服务提供增强功能。</p><h3 id="服务网格"><a href="#服务网格" class="headerlink" title="服务网格"></a>服务网格</h3><p>边车模式是服务网格的核心组件，用于实现服务间的通信、负载均衡和安全策略。</p><h3 id="日志收集"><a href="#日志收集" class="headerlink" title="日志收集"></a>日志收集</h3><p>边车可以收集服务的日志并发送到集中式日志管理系统，便于监控和分析。</p><h3 id="监控代理"><a href="#监控代理" class="headerlink" title="监控代理"></a>监控代理</h3><p>边车还可以作为监控代理，收集服务的性能指标并发送到监控系统，帮助运维人员快速定位问题。</p><hr><p>通过以上六种核心设计模式，微服务架构能够实现高可用性、可扩展性和灵活性。在实际项目中，可以根据业务需求选择合适的模式，并结合工具和框架（如 Spring Cloud、Istio 等）进行实现。</p>]]></content>
</entry>
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