javatcp实现一对一聊天

要实现Java TCP的一对一聊天，可以按照以下步骤进行：

1. 创建一个ServerSocket来监听客户端的连接请求：

ServerSocket serverSocket = new ServerSocket(port);
Socket clientSocket = serverSocket.accept();

2. 在客户端中创建一个Socket来连接服务器：

Socket socket = new Socket(serverHost, serverPort);

3. 在服务器和客户端中都创建一个输入输出流，用于发送和接收消息：

// 服务器端
InputStream inputStream = clientSocket.getInputStream();
OutputStream outputStream = clientSocket.getOutputStream();

// 客户端
InputStream inputStream = socket.getInputStream();
OutputStream outputStream = socket.getOutputStream();

4. 使用输入输出流进行消息的发送和接收：

// 服务器端
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
PrintWriter writer = new PrintWriter(outputStream, true);

String message = reader.readLine(); // 读取客户端发送的消息
writer.println("Server received your message: " + message); // 发送回复消息给客户端

// 客户端
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
PrintWriter writer = new PrintWriter(outputStream, true);

writer.println("Hello, server!"); // 发送消息给服务器
String response = reader.readLine(); // 读取服务器回复的消息

5. 在服务器和客户端中都需要使用多线程来处理多个连接请求，否则会阻塞主线程。

完整的示例代码如下：

服务器端：

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

public class Server {

    public static void main(String[] args) throws IOException {
        int port = 8888;
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("Server started on port " + port);

        while (true) {
            Socket clientSocket = serverSocket.accept();
            System.out.println("Client connected: " + clientSocket.getInetAddress().getHostAddress());

            new Thread(() -> {
                try {
                    InputStream inputStream = clientSocket.getInputStream();
                    OutputStream outputStream = clientSocket.getOutputStream();

                    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
                    PrintWriter writer = new PrintWriter(outputStream, true);

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

                    clientSocket.close();
                    System.out.println("Client disconnected: " + clientSocket.getInetAddress().getHostAddress());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }).start();
        }
    }

}

客户端：

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

public class Client {

    public static void main(String[] args) throws IOException {
        String serverHost = "localhost";
        int serverPort = 8888;

        Socket socket = new Socket(serverHost, serverPort);
        System.out.println("Connected to server: " + socket.getInetAddress().getHostAddress());

        InputStream inputStream = socket.getInputStream();
        OutputStream outputStream = socket.getOutputStream();

        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        PrintWriter writer = new PrintWriter(outputStream, true);

        writer.println("Hello, server!");

        String response = reader.readLine();
        System.out.println("Received response from server: " + response);

        socket.close();
        System.out.println("Disconnected from server.");
    }

}

以上代码可以实现在本地进行一对一的聊天。如果要在不同的机器上进行聊天，需要将服务器端的IP地址替换为服务器的公网IP地址，并且需要在服务器端的防火墙中开放对应的端口。