iluwatar#2898 Added more unit tests and refactored code

Author: Ehspresso

Diff for: publisher-subscriber/README.md renamed to publish-subscribe/README.md

@@ -1,5 +1,5 @@
 ---
-title: Publish-Subscribe pattern
+title: Publish-Subscribe
 category: Behavioral
 language: en
 tag:
@@ -135,7 +135,7 @@ public class TLender {
             LOGGER.error("An error has occurred!", e);
         }
 
-        TLender tLender = new TLender(topicCFName, topicName);
+        TLender lender = new TLender(topicCFName, topicName);
 
         System.out.println ("TLender Application Started");
         System.out.println ("Press enter to quit application");
@@ -151,11 +151,11 @@ public class TLender {
                 //Exit if user pressed enter or line is blank
                 if (line == null || line.trim().length() == 0) {
                     System.out.println("Exiting...");
-                    tLender.exit();
+                    lender.exit();
                 }
                 else { //publish the entered rate
                     double newRate = Double.parseDouble(line);
-                    tLender.publishRate(newRate);
+                    lender.publishRate(newRate);
                 }
             }
         } catch(IOException e) {
@@ -186,15 +186,6 @@ Initial rate is 6.0
 Waiting for new rates...
 Press enter to quit application
 
-Running the class:
-
-The class must be run after the TLender class is running since TLender spins up the activeMQ broker.
-
-In order to see the messages being sent to multiple subscribers multiple instance of the TBorrower class need to be run. Either run multiple instances in an IDE or execute the following command in a command line from the root folder after generating the target folder:
-
-
-mvn exec:java -Dexec.mainClass=com.iluwatar.publishersubscriber.TBorrower -Dexec.args="TopicCF RateTopic 6"
-
 ```java
 public class TBorrower implements MessageListener {
 
@@ -282,7 +273,7 @@ public class TBorrower implements MessageListener {
             System.exit(0);
         }
 
-        TBorrower tBorrower = new TBorrower(topicCF, topicName, rate);
+        TBorrower borrower = new TBorrower(topicCF, topicName, rate);
 
         try {
             // Run until enter is pressed
@@ -291,7 +282,7 @@ public class TBorrower implements MessageListener {
             System.out.println ("TBorrower application started");
             System.out.println ("Press enter to quit application");
             reader.readLine();
-            tBorrower.exit();
+            borrower.exit();
         } catch (IOException ioe) {
             ioe.printStackTrace();
         }
@@ -316,6 +307,7 @@ public class TBorrower implements MessageListener {
 ```
 
 ## Class diagram
+![alt text](./etc/publishsubscribe.urm.png "Publish Subscribe class diagram")
 
 ## Applicability
 

Diff for: publish-subscribe/USAGE.md

@@ -0,0 +1,8 @@
+Running the Borrower class:
+
+The class must be run after the TLender class is running since TLender spins up the activeMQ broker.
+
+In order to see the messages being sent to multiple subscribers multiple instance of the TBorrower class need to be run. Either run multiple instances in an IDE or execute the following command in a command line from the root folder after generating the target folder:
+
+
+mvn exec:java -Dexec.mainClass=com.iluwatar.publishsubscribe.Borrower -Dexec.args="TopicCF RateTopic 6"

Diff for: publisher-subscriber/pom.xml renamed to publish-subscribe/pom.xml

@@ -35,7 +35,7 @@
         <artifactId>java-design-patterns</artifactId>
         <version>1.26.0-SNAPSHOT</version>
     </parent>
-    <artifactId>publishersubscriber</artifactId>
+    <artifactId>publishsubscribe</artifactId>
 
     <dependencies>
         <dependency>
@@ -58,11 +58,6 @@
             <artifactId>xbean-spring</artifactId>
             <version>4.24</version>
         </dependency>
-        <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>1.2.17</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.activemq.tooling</groupId>
             <artifactId>activemq-junit</artifactId>

Diff for: publisher-subscriber/src/main/java/com/iluwatar/publishersubscriber/TBorrower.java renamed to publish-subscribe/src/main/java/com/iluwatar/publishsubscribe/Borrower.java

@@ -1,4 +1,4 @@
-package com.iluwatar.publishersubscriber;
+package com.iluwatar.publishsubscribe;
 
 import lombok.extern.slf4j.Slf4j;
 import javax.jms.BytesMessage;
@@ -19,14 +19,16 @@
 import java.io.InputStreamReader;
 
 @Slf4j
-public class TBorrower implements MessageListener {
+public class Borrower implements MessageListener {
 
   private TopicConnection tConnection;
   private TopicSession tSession;
   private Topic topic;
   private double currentRate;
+  private static final String ERROR = "An error has occured!";
+  private double newRate;
 
-  public TBorrower(String topicCFName, String topicName, double initialRate) {
+  public Borrower(String topicCFName, String topicName, double initialRate) {
 
     currentRate = initialRate;
 
@@ -50,44 +52,37 @@ public TBorrower(String topicCFName, String topicName, double initialRate) {
       tConnection.start();
       System.out.println("Initial rate is " + currentRate + " \nWaiting for new rates...");
     } catch(NamingException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     }
   }
 
   //This method is called asynchronously by the activeMQ broker
   public void onMessage(Message message) {
-
     try {
       BytesMessage bMessage = (BytesMessage) message;
-      double newRate = ((BytesMessage) bMessage).readDouble();
+      double newRate = bMessage.readDouble();
+      setNewRate(newRate);
 
       if (currentRate - newRate >= 1)
         System.out.println("New Rate is " + newRate + " - Consider refinancing");
       else
         System.out.println("New Rate is " + newRate + " - Consider keeping current rate");
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     }
     System.out.println("Waiting for new rates...");
   }
 
-  private void exit() {
+  public boolean close() {
     try {
       tConnection.close();
+      return true;
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
+      return false;
     }
-    System.exit(0);
   }
 
   public static void main(String[] args) {
@@ -105,7 +100,7 @@ public static void main(String[] args) {
       System.exit(0);
     }
 
-    TBorrower tBorrower = new TBorrower(topicCF, topicName, rate);
+    Borrower borrower = new Borrower(topicCF, topicName, rate);
 
     try {
       // Run until enter is pressed
@@ -114,9 +109,10 @@ public static void main(String[] args) {
       System.out.println ("TBorrower application started");
       System.out.println ("Press enter to quit application");
       reader.readLine();
-      tBorrower.exit();
-    } catch (IOException ioe) {
-      ioe.printStackTrace();
+      borrower.close();
+      System.exit(0);
+    } catch (IOException e) {
+      LOGGER.error(ERROR, e);
     }
   }
 
@@ -135,4 +131,8 @@ public Topic getTopic() {
   public double getCurrentRate() {
     return currentRate;
   }
+
+  public double getNewRate() { return newRate; }
+
+  private void setNewRate(double newRate) { this.newRate = newRate; }
 }

Diff for: publisher-subscriber/src/main/java/com/iluwatar/publishersubscriber/TLender.java renamed to publish-subscribe/src/main/java/com/iluwatar/publishsubscribe/Lender.java

@@ -1,4 +1,4 @@
-package com.iluwatar.publishersubscriber;
+package com.iluwatar.publishsubscribe;
 
 import lombok.extern.slf4j.Slf4j;
 import org.apache.activemq.broker.BrokerService;
@@ -14,18 +14,23 @@
 import javax.naming.InitialContext;
 import javax.naming.NamingException;
 import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.util.Properties;
 
 @Slf4j
-public class TLender {
+public class Lender {
 
   private TopicConnection tConnection;
   private TopicSession tSession;
   private Topic topic;
   private TopicPublisher publisher;
+  private static final String ERROR = "An error has occured!";
 
-  public TLender(String topicCFName, String topicName) {
+  public Lender(String topicCFName, String topicName) {
 
     try {
       //create context and retrieve objects from directory
@@ -44,17 +49,13 @@ public TLender(String topicCFName, String topicName) {
 
       tConnection.start();
     } catch(NamingException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     }
   }
 
-  private void publishRate(double newRate) {
+  public void publishRate(double newRate) {
 
     try {
       //create JMS message
@@ -64,21 +65,18 @@ private void publishRate(double newRate) {
       //publish message
       publisher.publish(message);
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
     }
   }
 
-  private void exit() {
+  public boolean close() {
     try {
       tConnection.close();
+      return true;
     } catch(JMSException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
-      System.exit(1);
+      LOGGER.error(ERROR, e);
+      return false;
     }
-    System.exit(0);
   }
 
   public static void main(String[] args) {
@@ -90,26 +88,35 @@ public static void main(String[] args) {
       topicCFName = args[0];
       topicName = args[1];
     } else {
-      System.out.println("Invalid arguments. Should be: ");
-      System.out.println("java TLender [factory] [topic]");
+      LOGGER.info("Invalid arguments. Should be: ");
+      LOGGER.info("java TLender [factory] [topic]");
       System.exit(1);
     }
 
     try {
+      //Get configuration properties
+      Properties props = new Properties();
+      InputStream in = new FileInputStream("publish-subscribe/src/main/resources/config.properties");
+      props.load(in);
+      in.close();
+
       // Create and start activeMQ broker. Broker decouples publishers and subscribers.
-      //Additionally brokers manage threads and asynchronous sending and receiving of messages.
+      // Additionally brokers manage threads and asynchronous sending and receiving of messages.
       BrokerService broker = new BrokerService();
-      broker.addConnector("tcp://localhost:61616");
+      broker.addConnector(props.getProperty("ADDRESS"));
       broker.start();
 
+    } catch(FileNotFoundException e) {
+      LOGGER.error(ERROR, e);
+    } catch(IOException e) {
+      LOGGER.error(ERROR, e);
     } catch(Exception e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
+      LOGGER.error(ERROR, e);
     }
 
-    TLender tLender = new TLender(topicCFName, topicName);
+    Lender lender = new Lender(topicCFName, topicName);
 
-    System.out.println ("TLender Application Started");
+    LOGGER.info("TLender Application Started");
     System.out.println ("Press enter to quit application");
     System.out.println ("Enter: Rate");
     System.out.println("\ne.g. 6.8");
@@ -123,16 +130,16 @@ public static void main(String[] args) {
         //Exit if user pressed enter or line is blank
         if (line == null || line.trim().length() == 0) {
           System.out.println("Exiting...");
-          tLender.exit();
+          lender.close();
+          System.exit(0);
         }
         else { //publish the entered rate
           double newRate = Double.parseDouble(line);
-          tLender.publishRate(newRate);
+          lender.publishRate(newRate);
         }
       }
     } catch(IOException e) {
-      e.printStackTrace();
-      LOGGER.error("An error has occurred!", e);
+      LOGGER.error(ERROR, e);
     }
   }
 

Diff for: publish-subscribe/src/main/resources/config.properties

@@ -0,0 +1 @@
+ADDRESS=tcp://localhost:61616