如何实现Java Socket的双向通信

要实现Java Socket的双向通信，你需要创建一个服务器端和客户端，它们可以通过套接字（Socket）进行数据的发送和接收。以下是一个简单的示例，展示了如何实现双向通信。

首先，我们创建一个服务器端：

import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) throws IOException {
        int port = 12345;
        ServerSocket serverSocket = new ServerSocket(port);

        System.out.println("Server is running on port: " + port);

        Socket socket = serverSocket.accept();
        System.out.println("Client connected");

        InputStream input = socket.getInputStream();
        OutputStream output = socket.getOutputStream();

        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        PrintWriter writer = new PrintWriter(output, true);

        String line;
        while (true) {
            line = reader.readLine();
            if (line != null) {
                System.out.println("Received from client: " + line);
                writer.println("Server received: " + line);
            }
        }
    }
}

接下来，我们创建一个客户端：

import java.io.*;
import java.net.*;

public class Client {
    public static void main(String[] args) throws IOException {
        String host = "localhost";
        int port = 12345;

        Socket socket = new Socket(host, port);
        System.out.println("Connected to server");

        InputStream input = socket.getInputStream();
        OutputStream output = socket.getOutputStream();

        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        PrintWriter writer = new PrintWriter(output, true);

        BufferedReader userInput = new BufferedReader(new InputStreamReader(System.in));

        String line;
        while (true) {
            System.out.print("Enter message: ");
            line = userInput.readLine();
            writer.println(line);

            line = reader.readLine();
            if (line != null) {
                System.out.println("Server response: " + line);
            }
        }
    }
}

在这个示例中，服务器端和客户端都使用了Socket对象来创建连接。服务器端使用ServerSocket对象监听指定端口，等待客户端连接。当客户端连接后，服务器端和客户端可以通过InputStream和OutputStream进行数据的读取和写入，从而实现双向通信。

要运行此示例，请先运行服务器端，然后运行客户端。你将看到它们之间的双向通信。