我自己也写了一个这样的程序，不过我参考了这一个代码，而且给了我启发，而且比我的要简洁，就直接上吧。程序中最大的变化就是在服务器端，我已经在关键的地方潜入了解释。好吧，直接上代码。
服务器端：
import java.net.*;
import java.util.*;
public class ChatServer {
public static void main(String args[]) {
Hashtable<String,DataOutputStream> userList = new Hashtable<String,DataOutputStream>();
String name;
DataInputStream dis;
DataOutputStream dos;
try{
//监听9999端口
ServerSocket ss = new ServerSocket(9999);
//始终是循环接收客户端的请求
while(true){
Socket s = ss.accept();
//获得输入流
dis = new DataInputStream(s.getInputStream());
//获得输出流
dos = new DataOutputStream(s.getOutputStream());
//读取客户端传送过来的名字信息
name = dis.readUTF();
// name = s.getPort()+"";
//System.out.println("abc"+name);
//把客户端传送过来的名字信息以及是输出流以键值对的形式保存在Hashtable当中
userList.put(name,dos);
//把1.客户端传送过来的参数
//2.输入流对象
//3. 把(1)和输出流的HashTable
//作为参数去启动一个线程
new MyServerReader(name,dis,userList).start();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
class MyServerReader extends Thread{
private String name;
private DataInputStream dis;
private Hashtable<String,DataOutputStream> userList;
public MyServerReader(String name,DataInputStream dis,Hashtable<String,DataOutputStream> userList ){
this.name = name;
this.dis = dis;
this.userList = userList;
}
public void run(){
String info;
try{
transmitMessage(name + " in!","--Server Info--");
//时刻判断输入的字符当中是否包含有bye
while(true){
//时刻读取字符
info = dis.readUTF();
System.out.println("Server========>"+info);
if(info.equals("bye")){
DataOutputStream dos = (DataOutputStream)(userList.get(name));
Thread.sleep(1000);
dos.close();
dis.close();
userList.remove(name);
transmitMessage(name + " out!","--Server Info--");
break;
}else if(info.length()>0){
//如果输入的字符不是bye，并且是有内容的就把数据发送出去
transmitMessage(info,name);
}
}
}catch (Exception e) {
}
}
public void transmitMessage(String msg,String name){
Collection doses = userList.values();
DataOutputStream dos;
for(Object o: doses){
dos = (DataOutputStream)o;
try{
//向所有的连接客户端发送信息，这里可以通过扩展发送给指定人
dos.writeUTF(name + ":" + msg);
}catch(Exception e){
}
}
}
}
客户端：
import java.net.*;
import java.awt.*;
import java.awt.event.*;
public class ChatClient {
private String name;
private Socket s;
private DataInputStream dis;
private DataOutputStream dos;
private Frame f;
private TextArea ta;
private TextField tf;
private boolean runnable = true;
public static void main(String args[]) {
ChatClient cc = new ChatClient();
cc.createUI();
cc.inputName();
cc.connect();
cc.createThread();
}
public void createUI(){
f = new Frame("Client");
ta = new TextArea();
ta.setEditable(false);
tf = new TextField();
Button send = new Button("Send");
Panel p = new Panel();
p.setLayout(new BorderLayout());
p.add(tf,"Center");
p.add(send,"East");
f.add(ta,"Center");
f.add(p,"South");
MyClientListener listener = new MyClientListener(this);
send.addActionListener(listener);
tf.addActionListener(listener);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
ChatClient.this.shutDown();
}
});
f.setSize(400,400);
f.setLocation(600,0);
f.setVisible(true);
tf.requestFocus();
}
public void inputName(){
String name = javax.swing.JOptionPane.showInputDialog("Input Your Name:");
this.setName(name);
f.setTitle(name);
}
public void connect(){
try {
s = new Socket("127.0.0.1",9999);
dos = new DataOutputStream(s.getOutputStream());
dis = new DataInputStream(s.getInputStream());
dos.writeUTF(name);
}catch (IOException e) {
e.printStackTrace();
}
}
public void createThread(){
MyClientReader reader = new MyClientReader(this);
reader.start();
}
public void stop(){
runnable = false;
}
public void shutDown(){
try{
dos.writeUTF("bye");
ta.append("Exit in 5 seconds!");
this.stop();
Thread.sleep(5000);
dis.close();
dos.close();
s.close();
}catch(Exception e){
}
System.exit(0);
}
public boolean getRunnable(){
return runnable;
}
public void setName(String name){
this.name = name;
}
public DataInputStream getDataInputStream(){
return dis;
}
public DataOutputStream getDataOutputStream(){
return dos;
}
public TextArea getTextArea(){
return ta;
}
public TextField getTextField(){
return tf;
}
}
class MyClientListener implements ActionListener{
private ChatClient client;
public MyClientListener(ChatClient client){
this.client = client;
}
public void actionPerformed(ActionEvent e){
TextField tf = client.getTextField();
String info = tf.getText();
try{
client.getDataOutputStream().writeUTF(info);
}catch (IOException e1) {
e1.printStackTrace();
}
if(info.equals("bye")){
client.shutDown();
}
tf.setText("");
tf.requestFocus();
}
}
class MyClientReader extends Thread{
private ChatClient client;
public MyClientReader(ChatClient client){
this.client = client;
}
public void run(){
String info;
DataInputStream dis = client.getDataInputStream();
TextArea ta = client.getTextArea();
try{
while(client.getRunnable()){
info = dis.readUTF();
System.out.println("Client=====>"+info);
ta.append(info + "\n");
}
}catch (IOException e) {
}
}
}