请各位帮帮十分无奈的我啊~~~！
本人在做一个有关UDP传输的东西~~！这是我们实习的课题，眼看实习马上就要结束了，可是程序却一直卡着进行不下去了！
课题的要求就是：一个server,一个client, server 不断的发图片和文本等系列文件~~！
server端的界面要有个文件列表供选择发送~~！发送过去的东西要显示客户端~~！
最后的效果就时，屏幕里面每隔几秒就出现一张图片~~！
我们现在的进度还只做到传一个图片~~！一个文本~~！我们现在遇到了一个问题，以前，我们传输了一个1。53kb的图片，成功传输，成功接收！但是当我们用了一个120kb的图片传输的时候，发现有信息丢失现象，所以我们决定标记每个packet,以及给他们编号，做完后发现不理想，接受到的图片，一半是完整的，另外一半是条纹，意味着我的第二个packet发送不成功~~！
客户端：
import java.net.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import javax.swing.*;
public class BroadcastClient{
static TextArea ta;
Frame f;
Panel p,p1;
public static final
int PORT = 1200;
public static int size;
public void createFrame() {
p=new Panel();
p1=new Panel();
Icon pp1 = new ImageIcon( "brios91.jpg " );
JButton b4=new JButton(pp1);
ta=new TextArea();
f=new Frame( "BroadcastClient ");
p.setLayout(new GridLayout(2,1));
p.add(b4);
p.add(ta);
f.setSize(300,300);
f.setLayout(new BorderLayout());
f.add(p,BorderLayout.WEST);
f.add(p1,BorderLayout.EAST);
f.setVisible(true);
f.pack();
WindowHandler wh = new WindowHandler();
f.addWindowListener(wh);
}
public class WindowHandler extends WindowAdapter {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}
public static void main(String args[]) throws Exception{
BroadcastClient win = new BroadcastClient();
win.createFrame();
MulticastSocket socket;
DatagramPacket packet;
InetAddress address;
address = InetAddress.getByName( "230.0.0.1 ");
socket = new MulticastSocket(PORT);
//join a Multicast group and send the group salutations
socket.joinGroup(address);
System.out.println( "joined ");
File received = new File( "receive.txt ");
FileOutputStream fos = new FileOutputStream(received);
int num;
int count=0;
while (true) {
packet = new DatagramPacket(new byte[1024], 1024);
// receive the packets
socket.receive(packet);
num=packet.getLength();
System.out.println( "Length: "+packet.getLength());
count++;
System.out.println(count);
//create a file to put the recieve data
byte[] data = new byte[packet.getLength()];
byte[] temp = packet.getData();
//throw out the extra length
for (int i = 0; i < data.length; i++) {
data[i] = temp[i];
}
if(count==20)
{
break;
}
// Read and display data
fos.write(data);
}
fos.close();
ta.append( "\nFile : "+received.getName()+ "\nSize : "+received.length()+ "byte ");
FileInputStream fis=new FileInputStream(received);
BufferedReader br=new BufferedReader(new InputStreamReader(fis));
int b=fis.available();
int c;
String st2;
while((st2=br.readLine())!=null){
System.out.println(st2);
ta.append( "\n "+st2);
}
}
// main
} // class Broadcast
server:
import java.net.*;
import java.io.*;
import java.util.*;
import java.io.DataInputStream;
import java.io.FileInputStream;
public class BS{
public static final int PORT = 1200;
private static int size;
public static void main(String args[]) throws Exception{
MulticastSocket socket;
DatagramPacket packet;
InetAddress address = InetAddress.getByName( "230.0.0.1 ");
socket = new MulticastSocket();
// join a Multicast group and send the group salutations
socket.joinGroup(address);
for(;;){
Thread.sleep(3000);//keep transforing packet
// Create a data input stream
DataInputStream fis = new DataInputStream(new FileInputStream( "bobmgame.txt "));
size = fis.available();
int available = size;
int count=0;
// Read and display data
while (available> 0) {
byte[] data2 = new byte[1024];
if (available> 1024)
fis.read(data2,0,1024);
else
fis.read(data2,0,available);
if
(available> = data2.length)
packet = new DatagramPacket (data2,data2.length,address,PORT);
else
packet = new DatagramPacket (data2,available,address,PORT);
//Sends the packet
socket.send(packet);
System.out.println(packet);
System.out.println(packet.getLength());
count++;
System.out.println( "\ncount: "+count);
available-=1024;
}
fis.close();
} // main
} // class BroadcastServer
详聊：qq38132124,请注java
[解决办法]
就是用UDP模拟TCP传输吧？
[解决办法]
我简单看了一下，在client read数据的时候不要用readLine。
为了保证数据传输的完整性，你可以定义一下报文头和报文押(采用摘要算法生成)。
虽然udp传输不可靠，一般情况下，也不会出现楼主你说的这种情况。
