Java 中 Socket 通信

1、在服务器端与客户端通信之前必须先保证服务器连接成功

a、创建一个服务器端程序 ：

package com.sunplus.app;

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class TcpServer {
    private ServerSocket serverSocket = null;
    private final int port = 10004; 

    private static TcpServer instance = null;
    static {
        instance = new TcpServer();
    }

    private TcpServer() {
    }

    public static TcpServer getInstance() {
        return instance;
    }

    public static void main(String[] args) throws Exception {

        getInstance().createSocket();

    }

    private void createSocket() {
        try {
            serverSocket = new ServerSocket(port); // 设置服务器端口号
            getInfo();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 接收客户端数据
     */
    private void getInfo() {
        try {
            Socket socket = serverSocket.accept();
            InputStream in = socket.getInputStream();
            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = in.read(buffer)) != -1) {
                System.out.println(new String(buffer, 0, len));
            }
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

b、创建一个客户端程序：

package com.sunplus.app;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class TcpClient {
    public static void main(String[] args) {
        writeData();
    }

    private static void writeData() {
        Socket socket = null;
        try {
            socket = new Socket("172.20.224.12", 10004);
            OutputStream os = socket.getOutputStream();
            os.write("Hello".getBytes()); // 向服务器发送数据
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (socket != null)
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
        }

    }
}