JAVA UDP 图像传输实例(二)client

/** *//**
 * @(#)Client.java
 *
 *
 * @author pkgold1
 * @version 1.00 2007/4/16
 */

import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;



public class Client extends Frame implements  Runnable, ActionListener ...{
    Button b=new Button("get picture");
    ImageCanvas canvas;
        public Client() ...{
            super("I am a client");
            setSize(600,600);
            setVisible(true);
            b.addActionListener(this);
            add(b,BorderLayout.NORTH);
            canvas=new ImageCanvas();
            add(canvas,BorderLayout.CENTER);
            Thread thread=new Thread(this);
            validate();
            addWindowListener(new WindowAdapter()
            ...{
                public void windowClosing(WindowEvent e)...{
                    System.exit(0);
                }
            });
            thread.start();
         }
         public void actionPerformed(ActionEvent event)...{
             byte b[]="please send picture".trim().getBytes();
             try...{
                 InetAddress address=InetAddress.getByName("localhost");
                 DatagramPacket data=new DatagramPacket(b,b.length,address,7000);
                 DatagramSocket mailSend=new DatagramSocket();
                 mailSend.send(data);
                 System.out.println("client send data");
                 
             }
             catch(Exception e)...{
                 e.printStackTrace();
                 }
         }
     public void run()
     ...{
         DatagramPacket pack=null;
         DatagramSocket mailReceive=null;
         byte b[]=new byte[8192];
         ByteArrayOutputStream out=new ByteArrayOutputStream();
         try ...{
             pack=new DatagramPacket(b,b.length);
             mailReceive=new DatagramSocket(5678);
             System.out.println("reay receive data");
                }
                catch(Exception e)...{
                    e.printStackTrace();
                    
                }
         try ...{
             while(true)...{
                 mailReceive.receive(pack);
                 String message=new String(pack.getData(),0,pack.getLength());
                 if(message.startsWith("end"))
                 ...{
                     System.out.println("get all data ok");
                     break;
                 }
                 out.write(pack.getData(),0,pack.getLength());
                 System.out.println("I am getting data");
             }
             byte imagebyte[]=out.toByteArray();
             out.close();
             Toolkit tool=getToolkit();
             Image image=tool.createImage(imagebyte);
             canvas.setImage(image);
             System.out.println("paint image");
             canvas.repaint();
               validate();
         }
         catch(IOException e)...{
             e.printStackTrace();
             }
             
     }
     public static void main(String args[])
     ...{
         new Client();
     }
    
}

import java.awt.*;
import java.awt.event.*;
class ImageCanvas extends Canvas
...{
    Image image=null;
    ...{
        setSize(200,200);
    }
    public void paint(Graphics g)...{
        if(image!=null)
        ...{
            g.drawImage(image,0,0,this);
        }
        else
        ...{
            this.image=image;
        }
    }
    public void setImage(Image image)
    ...{
        this.image=image;
    }
    
}

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