一个简单的java聊天室

 利用java Socket编写的群聊室，可以自己拷过去试试

Server端：

package net3;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;

public class Server {
	private List clients = null;
	
	public static void main(String[] args) {
		new Server().startUp();
	}
	
	private void startUp() {
		ServerSocket ss = null;
		Socket s = null;
		try {
			ss = new ServerSocket(5858);
			clients = new ArrayList();
			while (true) {
				s = ss.accept();
				ServerThread st = new ServerThread(s);
				new Thread(st).start();
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (ss != null) 
					ss.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	private class ServerThread implements Runnable {
		private Socket s = null;
		private BufferedReader br;
		private PrintWriter out;
		private String name;
		private boolean flag = true;
		
		public ServerThread(Socket socket) throws IOException {
			this.s = socket;
			br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			out = new PrintWriter(socket.getOutputStream(), true);
			String str = br.readLine();
			name = str+"["+socket.getInetAddress().getHostAddress()+":"+socket.getPort()+"]";
			clients.add(this);
			send(name+"上线了");
		}
		
		private void send(String msg) {
			for (ServerThread st : clients)
				st.out.println(msg);
		}
		
		private void receive() throws IOException {
			String str = null;
			while ((str=br.readLine()) != null) {
				if (str.equalsIgnoreCase("quit")) {
					stop();
					out.println("disconnect");
					break;
				}
				send(name+":"+str);
			}
		}
		
		private void stop() {
			clients.remove(this);
			flag = false;
			send(name+"已经下线了");
		}

		@Override
		public void run() {
			try {
				while (true) {
					if (!flag) break;
					receive();
				}
			} catch (SocketException e) {
				stop();
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					if (s != null) 
						s.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		
	}
}

Client端

package net3;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client {
	private Socket s;
	private BufferedReader br; 
	private PrintWriter out;
	private boolean flag = true;
	
	public static void main(String[] args) {
		new Client().stratUp();
	}

	private void stratUp() {
		BufferedReader sbr = null;
		try {
			s = new Socket("127.0.0.1", 5858);
			out = new PrintWriter(s.getOutputStream(), true);
			br = new BufferedReader(new InputStreamReader(s.getInputStream()));
			out.println("老林");
//			out.println("老周");
			sbr = new BufferedReader(new InputStreamReader(System.in));
			
			new Thread(new ClientThread()).start();
			String str = null;
			while (flag && (str=sbr.readLine())!=null) {
				if (!flag) break;
				out.println(str);
			}
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (s != null) s.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			try {
				if (sbr != null) s.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	private void receive() {
		try {
			String rs = br.readLine();
			if (rs.equalsIgnoreCase("disconnect")) {
				flag = false;
				System.out.println("点击回车退出");
			}
			System.out.println(rs);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	private class ClientThread implements Runnable {

		@Override
		public void run() {
			while (true) {
				if (!flag) break;
				receive();
			}
		}
		
	}

}