chatserver.java

下载的JAVA局域网的聊天程序,请大下们帮我看看 里面有几个问题

/*	范例名称：聊天室程序
 * 	源文件名称：ChatClient.java/ChatServer.java
 *	要  点：
 *		1. Java Socket编程
 *		2. 多线程编程
 *		3. 程序体系结构及设计思想
 */

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Vector; //Vector 集合对于线程是安全的

public class ChatServer extends Frame implements WindowListener
{
	TextArea display;
	int num=1;
	int port;
	ServerSocket server;
	BufferedReader input;
	BufferedWriter output;
	Vector<String> msgV; //消息集合,用到泛型
	/*
	*构造方法完成初始化工作
	*/
	public ChatServer(int port1)
	{
		super("聊天室正在运行中.....");
		display=new TextArea(200,300);
		this.add("Center",display);
		addWindowListener(this);
		setSize(300,400);
		setVisible(true);
		this.port=port1;
		msgV=new Vector<String>(10); //指定向量集合初始容量
	}
	/**
	*关闭窗口事件
	*1.显示正在关闭chat server
	*2.在消息队列msgV中加入"shutdown"字符串
	*3.线程睡眠5001ms
	*/
	public void windowClosing(WindowEvent e)
	{
		display.append("服务器正在关闭中...\n");
		display.append("通知聊天者...\n");
		display.append("请等待中...");
		msgV.add("shutdown");	// 消息集合中增加shutdown	
		try{Thread.sleep(5000);}
		catch(Exception e2){}
		dispose();
		System.exit(0);
	}
	public void windowOpened(WindowEvent e)
	{
	}
	public void windowActivated(WindowEvent e)
	{
	}
	public void windowClosed(WindowEvent e)
	{
	}
	public void windowDeactivated(WindowEvent e)
	{
	}
	public void windowDeiconified(WindowEvent e)
	{
	}
	public void windowIconified(WindowEvent e)
	{
	}

	public void run()
	{
		try
		{
			server=new ServerSocket(port,3);
			display.append("聊天服务器运行中...\n");
			while(true) //让服务器线程一直运行
			{
				Socket clientSocket=server.accept();
				clientConnection conn=new clientConnection(clientSocket,num,display,msgV); //为客户创建服务线程
				display.append("第 "+(num++)+" 位聊天者\n");
			}
		}
		catch(IOException e)
		{
			System.out.println("连接不成功!");
		}
	}
	
	public static void main(String args[])
	{
		ChatServer chatServer=new ChatServer(7);
		chatServer.run();
	}
}

class clientConnection extends Thread //服务线程
{
	String name;
	Socket cSocket;
	BufferedReader input;
	PrintWriter output;
	
	int num;
	TextArea display; //服务器端显示区域
	Vector<String> msgV; 
	
	
	public clientConnection(Socket cSocket,int num,TextArea display,Vector<String> msgV)
	{
		try{
  			input = new BufferedReader(new InputStreamReader(cSocket.getInputStream())); //封装服务器端的输出流(对应于客户端输入流)
  			output = new PrintWriter(cSocket.getOutputStream(),true);//封装服务器端的输出流(对应于客户端输入流)
  			this.name=input.readLine();
  		}
		catch(IOException e)
		{
			e.printStackTrace();
		}
		
		this.cSocket = cSocket; 
  		this.num=num; //聊天者人数
  		this.display=display;
  		this.msgV=msgV;
 		this.start(); //启动自己的线程对象
	}
	
	synchronized public void run() //用到同步,防止多个聊天者同时修改display,msgV
	{
  		String line;
		try
  		{
   			while(true)
   			{
   				line = input.readLine();
   				if(line.equals("End")) //读取到客户端发来的消息,"End"代表聊天者离开了
   				{
     					display.append("系统消息 : "+name+" 离开了 !\n");
     					break;
     				}
    				
				if(line.equals("PleaseSendALL")) //读取到客户端发来的消息,"PleaseSendALL"代表聊天者发消息
				{
     					if(!msgV.isEmpty())  //消息集合有元素
     					{
       						int ii=msgV.size() ; //消息集合的大小
        					output.println(ii);
       						for(int i=0;i<msgV.size();i++)
          					{
                				    output.println(msgV.get(i)); //取出所有消息集合中,将消息内容都发到客户端
          					}
       						//output.println("end");
     					}
    				else 
    					output.println("0"); 
  				}
				else
				{
					line=name+" 说:"+ line+"\n"; //加入了换行符
					display.append(line); // 将客户端的消息添加到服务端的面板上
					msgV.add(line); // 将客户端的消息添加到消息集合中
				}
			}
		}
		catch(IOException ex)
		{
			ex.printStackTrace();
		}
		finally //用到fianlly块释放资源
		{
			try
			{
				cSocket.close(); //关闭套接字
			}
			catch(IOException ex2)
			{
				ex2.printStackTrace();
			}
		}		
	}
}