利用UDP协议高效传输文件

发送端

package com.qf.demo4;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;public class Send {public static void main(String[] args) {// 1 DatagramSocket socket &＃61;null;FileInputStream fis &＃61; null;try {socket &＃61; new DatagramSocket();// 2fis &＃61; new FileInputStream(new File("D:\\A.java"));int num &＃61; 0;byte[] bs &＃61; new byte[1024];while((num &＃61; fis.read(bs))!&＃61;-1){DatagramPacket packet &＃61; new DatagramPacket(bs, num, InetAddress.getLocalHost(), 5588);socket.send(packet);}// 因为没有传输完毕的标志, 随后在 传输入一个标志String string &＃61; "传输完毕";DatagramPacket packet &＃61; new DatagramPacket(string.getBytes(), string.getBytes().length,InetAddress.getLocalHost(), 5588);socket.send(packet);} catch (SocketException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally {if(socket!&＃61; null){socket.close();}if(fis!&＃61;null){try {fis.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}
}


接收端

package com.qf.demo4;import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;public class Receive {public static void main(String[] args) {
// 1 DatagramSocket socket &＃61; null;FileOutputStream fos &＃61;null;try {socket &＃61; new DatagramSocket(5588);fos &＃61; new FileOutputStream(new File("a.java"));while(true){// 没有结束 循环的标志byte[] buf &＃61; new byte[1024];DatagramPacket packet &＃61; new DatagramPacket(buf, buf.length);socket.receive(packet);String string &＃61; new String(packet.getData(), 0, packet.getLength());if("传输完毕".equals(string)){break;}fos.write(packet.getData(), 0, packet.getLength());fos.flush();}System.out.println("接收方接收数据完毕");} catch (SocketException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally {if(socket!&＃61; null){socket.close();}if(fos!&＃61;null){try {fos.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}
}