1、服务器端程序

package com.test3;

import java.io.*;

import java.net.*;

import java.awt.*;

import java.awt.event.*;

import java.util.*;

import javax.swing.*;

public class MyServer3 extends JFrame implements ActionListener{

	/**

	 * @param args

	 */

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		new MyServer3();

	}

	JTextArea jta = null;

	JTextField jtf = null;

	JButton sendBtn = null;

	JPanel jp = null;

	JScrollPane jsp = null;

	//把信息发给客户端的对象

	PrintWriter pw = null;

	public MyServer3()

	{

		//

		jta = new JTextArea();

		jtf = new JTextField(20);

		sendBtn = new JButton("send");

		sendBtn.addActionListener(this);

		sendBtn.setActionCommand("send");

		jsp = new JScrollPane(jta);

		jp = new JPanel();

		jp.add(jtf);

		jp.add(sendBtn);

		this.add(jsp,BorderLayout.CENTER);

		this.add(jp,BorderLayout.SOUTH);

		this.setSize(400, 300);

		this.setTitle("QQ简易聊天-服务器端");

		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		this.setVisible(true);

		this.setResizable(false);

		try {

			//服务器监听

			ServerSocket ss = new ServerSocket(9988);

			//等待客户端连接

			Socket s = ss.accept();

			BufferedReader br = new BufferedReader

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

			pw = new PrintWriter(s.getOutputStream(),true);

			//读取从客户端发来的信息

			while(true) {

				String info = br.readLine();

				jta.append("client  "+getTime()+"\r\n"+info+"\r\n");

			}

		} catch (Exception e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

	@Override

	public void actionPerformed(ActionEvent e) {

		// TODO Auto-generated method stub

		if(e.getActionCommand().equals("send")) {

			//把服务器在jtf写的内容发送给客户端

			String info = jtf.getText();

			jta.append("server  "+getTime()+"\r\n"+info+"\r\n");

			pw.println(info);

			//清空发送框内容

			jtf.setText("");

		}

	}

	//获取系统时间

	public String getTime()

	{

		Calendar c = Calendar.getInstance();//可以对每个时间域单独修改

		int hour = c.get(Calendar.HOUR_OF_DAY);

		int minute = c.get(Calendar.MINUTE);

		int second = c.get(Calendar.SECOND);

		return hour+":"+ minute+":"+second;

	}

}

2、客户端程序

package com.test3;

import java.io.*;

import java.net.*;

import java.awt.*;

import java.awt.event.*;

import java.util.*;

import javax.swing.*;

public class MyClient3 extends JFrame implements ActionListener{

	/**

	 * @param args

	 */

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		new MyClient3();

	}

	JTextArea jta = null;

	JTextField jtf = null;

	JButton sendBtn = null;

	JPanel jp = null;

	JScrollPane jsp = null;

	PrintWriter pw = null;

	public MyClient3()

	{

		//

		jta = new JTextArea();

		jtf = new JTextField(20);

		sendBtn = new JButton("send");

		sendBtn.addActionListener(this);

		sendBtn.setActionCommand("send");

		jsp = new JScrollPane(jta);

		jp = new JPanel();

		jp.add(jtf);

		jp.add(sendBtn);

		this.add(jsp,BorderLayout.CENTER);

		this.add(jp,BorderLayout.SOUTH);

		this.setSize(400, 300);

		this.setTitle("QQ简易聊天-客户端");

		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		this.setVisible(true);

		this.setResizable(false);

		try {

			Socket s = new Socket("127.0.0.1",9988);

			BufferedReader br = new BufferedReader

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

			pw = new PrintWriter(s.getOutputStream(),true);

			while(true) {

				//不停的读取服务器端发来的信息

				String info = br.readLine();

				jta.append("server  "+getTime()+"\r\n"+info+"\r\n");

			}

		} catch (Exception e) {

			// TODO: handle exception

		}

	}

	@Override

	public void actionPerformed(ActionEvent e) {

		// TODO Auto-generated method stub

		if(e.getActionCommand().equals("send")) {

			String info = jtf.getText();

			//把客户端发送的信息显示到jta

			jta.append("client  "+getTime()+"\r\n"+info+"\r\n");

			pw.println(info);

			jtf.setText("");

		}

	}

	//获取系统时间

	public String getTime()

	{

		Calendar c = Calendar.getInstance();//可以对每个时间域单独修改

		int hour = c.get(Calendar.HOUR_OF_DAY);

		int minute = c.get(Calendar.MINUTE);

		int second = c.get(Calendar.SECOND);

		return hour+":"+ minute+":"+second;

	}

}

3、演示