content: package com.ramaguru.amrita.cys.jpl.net;
  
  import java.io.*;
  import java.net.*;
  
  /**
   * The TCPServer class represents the server side of the TCP client-server application.
   * It listens for client connections and processes client requests.
   */
  public class TCPServer {
  
      /**
       * The main method is the entry point of the server application.
       *
       * @param args command line arguments
       */
      public static void main(String[] args) {
          try {
              // Create a server socket on port 4424
              ServerSocket serverSocket = new ServerSocket(4424);
              System.out.println("Server started. Waiting for clients...");
  
              while (true) {
                  // Accept client connection
                  Socket clientSocket = serverSocket.accept();
                  System.out.println("Client connected: " + clientSocket.getInetAddress().getHostAddress());
  
                  // Create input and output streams for client communication
                  BufferedReader inFromClient = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                  DataOutputStream outToClient = new DataOutputStream(clientSocket.getOutputStream());
  
                  // Read client request
                  String clientRequest = inFromClient.readLine();
                  System.out.println("Received from client: " + clientRequest);
  
                  // Process client request
                  String response = processRequest(clientRequest);
  
                  // Send response to client
                  outToClient.writeBytes(response + '\n');
                  System.out.println("Sent to client: " + response);
  
                  // Close client connection
                  clientSocket.close();
              }
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
  
      /**
       * Processes the client request and generates a response.
       * Modify this method to implement your specific server logic.
       *
       * @param request the client request
       * @return the response to the client
       */
      private static String processRequest(String request) {
          // Placeholder implementation
          return "Server response: " + request.toUpperCase();
      }
  }
  