服务器端代码：

package chat;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.net.ServerSocket;

import java.net.Socket;

import java.util.HashSet;

import java.util.Iterator;

public class sever {

/**

* 服务器端

* @param args

*/

public HashSet clients = new HashSet();

public sever() {

try {

ServerSocket ss = new ServerSocket(8888);

Socket socketaccept = new Socket();

while(true){

socketaccept = ss.accept();

clients.add(socketaccept);

new ServerThread(socketaccept,clients).start();

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

class ServerThread extends Thread{

private Socket socketaccept;

private HashSet clients;

public ServerThread(Socket socketaccept, HashSet clients) {

this.socketaccept = socketaccept;

this.clients = clients;

}

@Override

public void run() {

try {

DataInputStream din = new DataInputStream(socketaccept.getInputStream());

while(true){

SendMess(din.readUTF());

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

public void SendMess(String readUTF) {

Iterator iter = clients.iterator();

while(iter.hasNext()){

Socket temp = (Socket)iter.next();

try {

DataOutputStream dout = new DataOutputStream(temp.getOutputStream());

dout.writeUTF(readUTF);

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

public static void main(String[] args){

System.out.println("服务器已启动--");

new sever();

}

}

客户端代码：

import java.awt.BorderLayout;

import java.awt.FlowLayout;

import java.awt.Frame;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.net.Socket;

import java.net.UnknownHostException;

import java.text.SimpleDateFormat;

import java.util.Date;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JTextArea;

import javax.swing.JTextField;

import javax.swing.SwingUtilities;

public class client extends JFrame{

/**

* 客户端

* @param args

*/

private JTextArea jta;

private JTextField jtf;

private JButton jb;

private JLabel name;

private JPanel jp;

private static ThreadReceive trReceive = null;//接收线程

private static Socket sc;

public client(){

this.setSize(300, 350);

this.setTitle("聊天室");

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//退出

jta = new JTextArea(15,20);

jtf = new JTextField(15);

jb = new JButton("发送");

name = new JLabel("");

jp = new JPanel();

jp.setLayout(new FlowLayout());

jp.add(jb);

jp.add(jtf);

jp.add(name);

jb.addActionListener(new SendMess());//发送数据..

this.setLayout(new BorderLayout());

this.add(jta,BorderLayout.CENTER);

this.add(jp,BorderLayout.SOUTH);

getMess();

this.setVisible(true);

}

class ThreadReceive extends Thread{

public void run() {

DataInputStream din;

try {

while(true){

din = new DataInputStream(sc.getInputStream());

jta.append(din.readUTF()+"\n");

//System.out.println("接收数据: "+din.readUTF());

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

public void getMess() {

try {

sc = new Socket("127.0.0.1",8888);

trReceive = new ThreadReceive();

trReceive.start();//循环接收数据

//}

} catch (UnknownHostException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

name.setText(JOptionPane.showInputDialog(this,"请输入你的姓名"));

}//getMess

class SendMess implements ActionListener{

@Override

public void actionPerformed(ActionEvent e) {

SimpleDateFormat format = new SimpleDateFormat("yyyy:MM:dd");

String time = format.format(new Date());

try {

// while(true){//发送按钮

DataOutputStream dout = new DataOutputStream(sc.getOutputStream());

dout.writeUTF(time+' '+name.getText()+":"+jtf.getText());

//}

} catch (IOException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

}

}

public static void main(String[] args){

System.out.println("客户端..");

SwingUtilities.invokeLater(new Runnable() {

public void run() {

client thisClass = new client();

}

});

}

}采用socket编程，这个程序也是为了验证tcp通信可以多对1.  服务器端没有做界面。