chatserver.java

网络实验

import java.io.*;
import java.net.*;
import java.util.*;


public class ChatServer {
	DataInputStream dis = null;
	boolean started = false;
	ServerSocket ss = null;
	Socket s = null;
	List<Client> clients = new ArrayList<Client>();

	public static void main(String[] args) {
		new ChatServer().start();

	}
	
	public void start(){
		try{
			ss = new ServerSocket(8888);
			started = true;
		}catch(BindException be){
			System.out.println("Port is used");
			System.exit(0);
		}catch(IOException e){
			e.printStackTrace();
		}
		try{
			while(started){
				s = ss.accept();
System.out.println("A client connected!");
				Client c = new Client(s);
				clients.add(c);
				new Thread(c).start();
			}
			}catch(IOException e){
				
				e.printStackTrace();
			}finally{
					try {
						if(ss != null) ss.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
			}
		}
	
	
	class Client implements Runnable{
		Socket s = null;
		DataInputStream dis = null;
		DataOutputStream dos = null;
		boolean bConnected = false;
		
		public Client(Socket s){
			this.s = s;
			try{
			dis = new DataInputStream(this.s.getInputStream());
			dos = new DataOutputStream(this.s.getOutputStream());
			bConnected = true;
			}catch(IOException ioe){
				ioe.printStackTrace();
			}
		}
		
		public void send(String str){
			try {
				dos.writeUTF(str);
			} catch (IOException e) {
				clients.remove(this);
			}
		}
		
		public void run() {
			try{
				while(bConnected){
					String str = dis.readUTF();
					System.out.println(str);
					for(int i=0; i<clients.size();i++){
						Client c = clients.get(i);
						c.send(str);
					}
				}
			}catch(EOFException eo){
				System.out.println("client closed");
			}catch(IOException e){
				e.printStackTrace();
			}finally{
					try {
						if(dis != null) dis.close();
						if(dos != null) dos.close();
						if(s != null) s.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
			}
			
		}
		
	}

}