client码，如以下：

import java.io.*;

import java.net.*;

public class DailyAdviceClient {

	public void go(){

		try {

			Socket s=new Socket("127.0.0.1",4242);//建立对server的Socket连接

			//client从server读取数据

			//建立连接到socket上低层输入串流的InputStreamReader

			//InputStreamReader是低层和高层串流间的桥梁

			//s.getInputStream()从Socket取得输入串流

			InputStreamReader streamReader=new InputStreamReader(s.getInputStream());

			//建立BufferedReader来读取

			BufferedReader reader=new BufferedReader(streamReader);

			String adviceString=reader.readLine();

			System.out.println("Today you should: "+adviceString);

			//client向server发送数据

			//创建不带自己主动行刷新的PrintWriter对象。

			//假设加入第二个參数true,则为自己主动刷新，不须要写writer.flush()这行代码

			PrintWriter writer=new PrintWriter(s.getOutputStream());

			writer.println("Hello,I am Client2!");

			writer.flush();//刷新发送数据

			System.out.println("此套接字连接的远程地址："+s.getInetAddress().getHostAddress());

			System.out.println("此套接字绑定的本地地址："+s.getLocalAddress().getHostAddress());

			System.out.println("此套接字绑定的本地端口:"+s.getLocalPort());

			System.out.println("此套接字连接到的远程端口:"+s.getPort());

			s.close();//关闭socket

		} catch (IOException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

	public static void main(String[]args){

		DailyAdviceClient client=new DailyAdviceClient();

		client.go();

	}

}

server端代码例如以下：

import java.io.*;

import java.net.*;

public class DailyAdviceServer {

	String[] adviceList={"Take smaller bites","One word: inappropriate",""

			+ "Just for today,be honest","Tell your boss"};

	public void go(){

		try {

			//服务器应用程序对特定port创建出ServerSocket对象

			//这会让服务器应用程序监听来自4242port的client请求

			ServerSocket serverSocket=new ServerSocket(4242);

			//服务器进入无穷循环等待client的请求

			while(true){

				System.out.println("等待client连接...");

				//接收到用户连接请求后。此方法会返回一个socket。以便于client通信

				//此socket的port号和serverSocket的port号不同

				Socket sock=serverSocket.accept();//此方法会堵塞直到有连接请求到达

				System.out.println("此套接字连接的地址："+sock.getInetAddress().getHostAddress());

				System.out.println("此套接字绑定的本地地址："+sock.getLocalAddress().getHostAddress());

				System.out.println("此套接字绑定的本地port:"+sock.getLocalAddress());

				System.out.println("此套接字连接到的远程port:"+sock.getPort());

				//服务器向client发送数据

				PrintWriter writer=new PrintWriter(sock.getOutputStream());

				String adviceString=getAdvice();

				writer.println(adviceString);

				writer.flush();

				System.out.println(adviceString);

				//服务器接收client发送的数据

				InputStreamReader streamReader=new InputStreamReader(sock.getInputStream());

				BufferedReader reader=new BufferedReader(streamReader);

				String adviceStringREC=reader.readLine();

				System.out.println("REC: "+adviceStringREC);			

			}

		} catch (IOException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

	public String getAdvice(){

		int random=(int)(Math.random()*adviceList.length);

		return adviceList[random];

	}

	public static void main(String []args){

		DailyAdviceServer server=new DailyAdviceServer();

		server.go();

	}

}