UDP传送图片，有点小问题怎么解决下。

zly361814478 2012-10-22 07:58:52

服务器端：

import java.awt.image.BufferedImage;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.net.DatagramPacket;

import java.net.DatagramSocket;



import javax.imageio.ImageIO;

import javax.imageio.stream.FileImageInputStream;



public class UDpserver {

   public static void main(String[] args) throws Exception {

	DatagramSocket socket = new DatagramSocket(5000);

	byte[] b = new byte[100];

	DatagramPacket receivePacket = new DatagramPacket(b,b.length);

	socket.receive(receivePacket);

	if(0!=receivePacket.getLength()){  //检测到有信息发过来就向客户端发送一张图片

	  File file = new File("E:/123.png");

	  FileImageInputStream fiis = 

	  new FileImageInputStream(file);

	  BufferedImage image=ImageIO.read(fiis);//获取图像

	  ByteArrayOutputStream buf= 

	  new ByteArrayOutputStream((int)file.length());

	  ImageIO.write(image,"jpg",buf);

	  byte[] b1 =buf.toByteArray();

	  DatagramPacket sendPacket =new DatagramPacket(b1,(int)file.length(),

			  receivePacket.getAddress(),receivePacket.getPort());

	  socket.send(sendPacket);

	  socket.close();

	   }

     }

}

服务端

import java.awt.BorderLayout;

import java.awt.Canvas;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.image.BufferedImage;

import java.io.ByteArrayInputStream;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;



import javax.imageio.ImageIO;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;



public class Udpclient  implements ActionListener{

	JButton btn;

	JPanel jp;

	MyCanvas1 cav = new MyCanvas1();

	BufferedImage image;

	

    public Udpclient(){

    	JFrame jf= new JFrame("I am a client");

    	btn = new JButton("获取图像");

    	jp= new JPanel();

    	jf.add(btn,BorderLayout.NORTH);

    	btn.setSize(250,30);

    	btn.addActionListener(this);

    	cav.setPreferredSize(new Dimension(250,250));

    	jp.add(cav);

    	jf.add(jp,BorderLayout.SOUTH);

    	jf.pack();

    	jf.setVisible(true);

    	

    }

    class MyCanvas1 extends Canvas{

    	public void paint(Graphics g){

    		g.drawImage(image,0,0,this);

    	}

    }

    public void actionPerformed(ActionEvent e){

    	 

			try{

		    DatagramSocket socket = new DatagramSocket();

		    String str="请求图片";

		    DatagramPacket sendPacket = new DatagramPacket

		    		(str.getBytes(),str.length(),

		    		InetAddress.getByName("localhost"),5000);

		    socket.send(sendPacket);

			byte[] image1 = new byte[5000];

			DatagramPacket receivePacket =new DatagramPacket(image1,5000);

			socket.receive(receivePacket);

			ByteArrayInputStream bais = new ByteArrayInputStream

					(image1,0,receivePacket.getLength());

		       BufferedImage bi = ImageIO.read(bais);

		       image = bi;

		       cav.repaint();

		    socket.receive(receivePacket);

		    socket.close();

		    

		    }catch(Exception en){

		    	en.printStackTrace();

		    }

    }

    public static void main(String[] args) {

		new Udpclient();

	}

}