chatclient.java

这是用JAVA做的模拟QQ聊天工具

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.net.*;
import java.applet.Applet;

public class ChatClient extends Applet implements Runnable,ActionListener
{
	static CFrame frame;
	Thread kicker=null;                         
	JTextField user=new JTextField(20);      
	JTextArea text=new JTextArea(40,35);   
	JTextArea msg=new JTextArea();           
	ButtonGroup bg=new ButtonGroup();      
	JButton connect=new JButton("Connect");    
	JButton send=new JButton("Send");          
	JButton exit=new JButton("Exit");       
	Socket kkSocket=null;
	PrintStream os;      
	DataInputStream is;                         	
	public void init()//初始化
	{	
	    setLayout(new CardLayout()); 
	    //用户连接服务器界面 
	    JPanel p12=new JPanel(new FlowLayout());
	    p12.add(new JLabel("Username"));
	    p12.add(user);
	    p12.add(connect);
	    add("login",p12);
	    //用户登录后的界面		
		JPanel p4=new JPanel(new BorderLayout());
		JPanel p5=new JPanel(new BorderLayout());
		p5.add("North",new JLabel("Message Text"));
		text.setEditable(false);  //不可编辑                        
		p5.add("Center",new JScrollPane(text));  //滚动条
		JPanel p6=new JPanel(new GridLayout(1,4));
		p6.add(new JLabel(""));
		p6.add(send);             //发送按钮
		p6.add(exit);           //退出按钮
		p6.add(new JLabel(""));
		JPanel p7=new JPanel(new BorderLayout());
		p7.add("North",new JLabel("My message"));
		p7.add("Center",msg);
		p7.add("South",p6);
		p4.add("Center",p5);
		p4.add("South",p7);
		add("send",p4);      
		connect.addActionListener(this);
		send.addActionListener(this);
		exit.addActionListener(this);
	}	
	public void start()
	{
	}	
	public void stop() 
	{   //停止执行
		if(kicker!=null) kicker.stop();
		if(kkSocket!=null)
		{
			sendData("exit");//发送退出信息
			try
			{
				Thread.sleep(100);
			}
			catch(InterruptedException e)
			{
				System.out.println("Error:"+e);
			}
			closeSocket();
		}
	}	
	public void destroy()
	{
	}	
	public void run()
	{
		String fromServer=null;
		while((fromServer=getData())!=null) //获取信息
		    text.append(fromServer+"\n");   //添加到聊天区域后		    
		//否则关闭socket,回到登录界面
		kicker=null;
		closeSocket();
		((CardLayout)getLayout()).show(this,"login");
		frame.setTitle("Exit");
		frame.pack();
		frame.resize(500,400);
	}
	
	boolean connectHost()
	{  //连接服务器
		try
		{
			kkSocket=new Socket("localhost",4567);
			os=new PrintStream(kkSocket.getOutputStream());
			is=new DataInputStream(kkSocket.getInputStream());
		}
		catch(UnknownHostException e)
		{  
			System.out.println("Error:"+e);
			return false;
		}
		catch(Exception e)
		{
			text.setText("Exception:   "+e);
			System.out.println("Excepton:   "+e);
			return false;
		}
		return true;
	}	
	String getData()//接受信息
	{  
		String fromServer;
		try
		{
			fromServer=is.readLine();
		}
		catch(Exception e)
		{
			text.setText("Error:"+e);
			System.out.println("Error:"+e);
			return null;
		}
		return fromServer;
	}	
	boolean sendData(String toServer) //发送消息
	{ 
		try
		{
			os.println(toServer);
			os.flush();
		}
		catch(Exception e)
		{
			text.setText("Error:"+e);
			System.out.println("Error:"+e);
			return false;
		}
		return true;
	}	
	void closeSocket() //关闭流和socket
	{ 
		try
		{
			os.close();
			is.close();
			kkSocket.close();
			kkSocket=null;
		}
		catch(Exception e)
		{
			text.setText("Error:"+e);
			System.out.println("Error:"+e);
		}
	}
		
	public void actionPerformed(ActionEvent e)//事件响应
	{ 
		if(e.getSource()==connect)
		{
			if(connectHost())//已连接
			{
				sendData(user.getText());//发送用户名和性别信息
				kicker=new Thread(this);
				kicker.start();
				text.setText("");
				msg.setText("");
				((CardLayout)getLayout()).show(this,"send");//切换到聊天界面
				frame.setTitle("Client-"+user.getText());
				frame.pack();
				frame.setSize(500,600);
			}
		}
		else if(e.getSource()==send)//发送消息
		{
			if(sendData(msg.getText())) //发送成功清空发送栏
				msg.setText("");
			else  //否则停止线程，切换到登录界面
			{ 
				kicker.stop();
				kicker=null;
				closeSocket();
				((CardLayout)getLayout()).show(this,"login");
				frame.setTitle("Client");
				frame.resize(500,400);
			}
		}
		else if(e.getSource()==exit)//用户退出，停止线程，切换到登录界面
		{
			kicker.stop();
			kicker=null;
			sendData("Exit");//发送退出信息
			closeSocket();
			((CardLayout)getLayout()).show(this,"exit");
			frame.setTitle("Client");
			frame.resize(500,400);
		}
	}
		
	public static void main(String[]args)
	{
		ChatClient client=new ChatClient();
		client.init();
		client.start();		
		frame=new CFrame("ChatroomClient",client);
		frame.setBackground(Color.lightGray);
		frame.add("Center",client);
		frame.resize(500,100);
		frame.show();
	}
}
class SimpleFrame extends Frame
{
	ChatClient client;	
	public SimpleFrame(String name,ChatClient client)//构造函数
	{
		super(name);
		this.client=client;
	}	
	public boolean handleEvent(Event e)
	{
		switch(e.id)
		{
			case Event.WINDOW_DESTROY:
			  client.stop();
			  client.destroy();
			  System.exit(0);
		}
		return super.handleEvent(e);
	}
}