java socket聊天

Java Socket 聊天是一种基于网络 Socket 编程的聊天应用程序。它可以让两个或多个用户通过网络实时通信、聊天。下面是一个简单的 Java Socket 聊天程序的示例：

服务端代码：

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

public class ChatServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(10007);
        } catch (IOException e) {
            System.err.println("Could not listen on port: 10007.");
            System.exit(1);
        }

        Socket clientSocket = null;
        try {
            System.out.println("Waiting for connection...");
            clientSocket = serverSocket.accept();
            System.out.println("Connection established with: " + clientSocket);
        } catch (IOException e) {
            System.err.println("Accept failed.");
            System.exit(1);
        }

        PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(
                new InputStreamReader(
                        clientSocket.getInputStream()));
        String inputLine;

        while ((inputLine = in.readLine()) != null) {
            System.out.println("Client: " + inputLine);
            out.println(inputLine);
            if (inputLine.equals("Bye."))
                break;
        }
        out.close();
        in.close();
        clientSocket.close();
        serverSocket.close();
    }
}

客户端代码：

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

public class ChatClient {
    public static void main(String[] args) throws IOException {

        Socket socket = null;
        PrintWriter out = null;
        BufferedReader in = null;

        try {
            socket = new Socket("localhost", 10007);
            out = new PrintWriter(socket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(
                    socket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: localhost.");
            System.exit(1);
        }

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

        while ((userInput = stdIn.readLine()) != null) {
            out.println(userInput);
            System.out.println("Server: " + in.readLine());
            if (userInput.equals("Bye."))
                break;
        }
        out.close();
        in.close();
        stdIn.close();
        socket.close();
    }
}

这个示例中，服务端监听本地的 10007 端口，客户端连接到服务端的该端口。当客户端连接成功后，客户端和服务端之间可以互相发送消息。

你可以在控制台中输入消息并发送到服务端，服务端会将接收到的消息打印到控制台中，然后将消息发送回客户端，客户端将接收到的消息打印到控制台中。

以上是一个简单的 Java Socket 聊天程序示例，你可以根据自己的需求进行修改和扩展。