SimpleHTTPServer.java

import com.sun.net.httpserver.HttpServer;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpExchange;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.nio.file.Files;
import java.util.HashMap;
import java.util.Map;

public class SimpleHTTPServer {
    private static final int PORT = 8000;
    private static final String ROOT_DIR = ".";
    private static final Map<String, String> MIME_TYPES = new HashMap<>();
    
    static {
        MIME_TYPES.put(".html", "text/html");
        MIME_TYPES.put(".css", "text/css");
        MIME_TYPES.put(".js", "application/javascript");
        MIME_TYPES.put(".webp", "image/webp");
    }

    public static void main(String[] args) throws IOException {
        HttpServer server = HttpServer.create(new InetSocketAddress(PORT), 0);
        server.createContext("/", new FileHandler());
        server.setExecutor(null);
        server.start();
        System.out.println("Server started on port " + PORT);
        System.out.println("Open http://localhost:" + PORT + " in your browser");
    }

    static class FileHandler implements HttpHandler {
        @Override
        public void handle(HttpExchange exchange) throws IOException {
            String path = exchange.getRequestURI().getPath();
            if (path.equals("/")) {
                path = "/index.html";
            }

            File file = new File(ROOT_DIR + path);
            if (!file.exists() || file.isDirectory()) {
                String response = "404 Not Found";
                exchange.sendResponseHeaders(404, response.length());
                try (OutputStream os = exchange.getResponseBody()) {
                    os.write(response.getBytes());
                }
                return;
            }

            String contentType = getContentType(file.getName());
            exchange.getResponseHeaders().set("Content-Type", contentType);
            exchange.sendResponseHeaders(200, file.length());
            
            try (OutputStream os = exchange.getResponseBody()) {
                Files.copy(file.toPath(), os);
            }
        }

        private String getContentType(String fileName) {
            int dot = fileName.lastIndexOf('.');
            if (dot > 0) {
                String extension = fileName.substring(dot).toLowerCase();
                String mimeType = MIME_TYPES.get(extension);
                if (mimeType != null) {
                    return mimeType;
                }
            }
            return "application/octet-stream";
        }
    }
}