Chat Server服务器代码片`.

// An highlighted block
import java.net.*;
import java.util.ArrayList;
import java.io.*;
public  class ChatServer {public static void main(String[] args) {// TODO Auto-generated method stub//构造一个端口6000的ServerSocket//这里构造serverSocket		 try(ServerSocket chat=new ServerSocket(6000)){SocketList list=new SocketList();System.out.println("聊天室启动...");while(true) {Socket connection=chat.accept();ThreadHander client=new ThreadHander(connection);Thread t=new Thread(client);list.addList(client);System.out.println(list.getList());t.start();}}catch(BindException ex) {System.err.println(ex.getMessage()+" 绑定端口失败!");}catch(SocketException ex) {System.err.println(ex.getMessage()+" 连接客户端失败");}catch(IOException ex) {System.err.println(ex.getMessage()+"测试");}}
}//线程对象实例数组
class SocketList{//静态数组private static ArrayList<ThreadHander> clients=new ArrayList<ThreadHander>();//添加对象public void  addList(ThreadHander m) {clients.add(m);}//返回数组public ArrayList<ThreadHander> getList() {return clients;		}//删除对象,发生错误时，就删除发生错误的对象public void removeList(ThreadHander m) {clients.remove(m);}
}//多个线程，用于连接多个客户端	class ThreadHander implements Runnable{private Socket socket;private PrintWriter write;private BufferedReader read;private String name;private ArrayList<ThreadHander> list;private SocketList SL;//类变量private boolean Flag=true;//标志位，如果是false则表示该子线程出现错误，然后退出循环，run()方法执行完毕退出，线程结束ThreadHander(Socket socket){this.socket=socket;}//发送数据private void send(String s) throws IOException{write.println(s);	write.flush();}//发送数据给其他人，实质是用遍历ThreadHander数组的，使用实例的send()方法private void sendOther(String s) {// TODO Auto-generated method stubtry {if(s.equals("")||s==null)return;list=SL.getList();for(ThreadHander th:list) {//System.out.println("this"+this);//System.out.println("th"+th);//如果是自己就不发送if(th==this)continue;	//name是客户加入时的名字if(s.equals("加入群聊"))th.send(name+s);elseth.send(name+": "+s);System.out.println(s);}}catch (IOException e) {System.err.println(e.getMessage()+"sendOther");SL.removeList(this);Flag=false;}}//接受数组方法private String recv() {	String s="";try {			s=read.readLine();}catch(SocketException e){System.err.println(e.getMessage()+"SocketException");SL.removeList(this);Flag=false;			}catch(IOException e){System.err.println(e.getMessage()+"IOException");//SL.removeList(this);//Flag=false;	}	System.out.println(s);return s;}@Overridepublic void run() {// TODO Auto-generated method stubtry {SL=new SocketList();write=new PrintWriter(socket.getOutputStream());read=new BufferedReader(new InputStreamReader(socket.getInputStream()));send("欢迎加入群聊");name=recv();//获取 该用户昵称sendOther("加入群聊");				while(Flag==true) {				sendOther(recv());}System.out.println(this+"线程连接中断，该线程结束");}catch(IOException ex){System.err.println(ex.getMessage()+"xianchengRun");}finally {try {socket.close();} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}}}}

ChatClient 客户端代码：

import javax.swing.JOptionPane;
import java.net.*;
import java.io.*;public class ChatClient {public static void main(String[] args) {// TODO Auto-generated method stubinitClient client=new initClient();client.qidong();}}class initClient{private static Socket socket;initClient(){socket=new Socket();}void qidong() {SocketAddress chatAddress=new InetSocketAddress("localhost",6000);try {		//连接服务器socket.connect(chatAddress);		String aName=JOptionPane.showInputDialog("请输入你的名字");ThreadRecv recv=new ThreadRecv(socket);ThreadSend send=new ThreadSend(socket,aName);Thread re=new Thread(recv);Thread se=new Thread(send);re.start();se.start();}catch(UnknownHostException ex){System.err.println("I can't find the host");}catch(SocketException ex) {System.err.println("Could not connect to the host");try {socket.close();System.out.println("socket资源关闭");}catch(IOException ex1) {ex1.printStackTrace();				}}catch(IOException ex) {System.err.println("连接断开失败");}}}//接收线程
class ThreadRecv implements Runnable{private Socket socket;private BufferedReader in;//读入流ThreadRecv(Socket aSocket){socket=aSocket;}@Overridepublic void run() {// TODO Auto-generated method stubtry {String string;in=new BufferedReader(new InputStreamReader(socket.getInputStream()));while(true) {string=in.readLine();	System.out.println(string);}}catch(SocketException ex) {System.err.println("连接服务器失败！！！");	try {socket.close();System.out.println("socket资源关闭\n退出程序!");//终止程序System.exit(0);								}catch(IOException ex1) {ex1.printStackTrace();				}}catch(IOException ex) {System.err.println("error错误！！！");}}
}//发送线程
class ThreadSend implements Runnable{private Socket socket;private PrintWriter out;//输出流private BufferedReader sin;private String name;//发送自己的名字ThreadSend(Socket aSocket,String aName){socket=aSocket;name=aName;}	@Overridepublic void run() {// TODO Auto-generated method stubtry {		out=new PrintWriter(socket.getOutputStream());//获取输出流sin=new BufferedReader(new InputStreamReader(System.in));		out.println(name);out.flush();while(!socket.isClosed()) {System.out.print("请输入内容:");String s=sin.readLine();out.println(s);out.flush();}}catch(IOException ex) {System.err.println("输出失败");}}
}

cmd执行Java程序，以管理员执行cmd
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