一个服务端 对应 一个客户端，双方可以通信。

1、服务端代码

public class EchoServerDemo {

public static void main(String[] args) {

// 端口号从 1024-65535

try {

ServerSocket ss = new ServerSocket(9007);

System.out.println("Server start...");

Socket socket = ss.accept();

//来自客户端信息

InputStream input = socket.getInputStream();

BufferedReader br = new BufferedReader(new InputStreamReader(input));

String info = br.readLine();

System.out.println(info);

//发送给客户端信息

OutputStream output = socket.getOutputStream();

PrintStream ps = new PrintStream(output);

ps.println("Server:hello1");

output.close();

input.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

2、客户端代码

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.PrintStream;

import java.net.Socket;

public class EchoClientDemo {

public static void main(String[] args) {

// 连接服务器

try {

Socket socket = new Socket("localhost",9007);

System.out.println("Client connect Server succ");

OutputStream out = socket.getOutputStream();

InputStream in = socket.getInputStream();

PrintStream ps = new PrintStream(out);

ps.println("Client:hello");

BufferedReader br = new BufferedReader(new InputStreamReader(in)); 

String info = br.readLine();

System.out.println(info);

out.close();

in.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}