开发学院WEB开发Jsp 利用Java语言实现数据报编程之单播 阅读

利用Java语言实现数据报编程之单播

 2008-01-05 19:34:11 来源:WEB开发网   
核心提示:实际上,单播就是一个报文从源主机向另一个目标主机发送,接收目标只有一个, 首先,写收发器类DatagramRecvSender_s,这个类既要发送数据报又要接收数据报,发送一个文件夹中的所有图片,一张一张的进行,接收是在一个线程中进行,每收完一个文件,就激活一个事件,事件处理器处理这个事件,利用Java语言实现数据报编

  实际上,单播就是一个报文从源主机向另一个目标主机发送,接收目标只有一个。
  首先,写收发器类DatagramRecvSender_s,这个类既要发送数据报又要接收数据报,发送一个文件夹中的所有图片,一张一张的进行,接收是在一个线程中进行,每收完一个文件,就激活一个事件,事件处理器处理这个事件。
  类清单为:
package recmail.multiservice;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import java.net.SocketAddress;
import java.net.UnknownHostException;
import java.net.InetSocketAddress;
import java.io.IOException;
import java.util.ArrayList;
import java.net.InetAddress;
import java.io.File;
import java.util.Iterator;
public class DatagramRecvSender_s extends DataSwapListenerAdapter
implements Runnable {
  public static final int DatagramPort = 10698;
  PRivate java.net.DatagramSocket road ;
  private InetAddress ia;
  DatagramPacket dp;
  public static final int Datagram_Length = 8192;
  private DataPacket cdp;
  private boolean ishandling = true;
  DataSwapEvent dsevent;
  /**
  * 这个构造器用于接收数据报.
  */
  public DatagramRecvSender_s() {
   try {
    System.out.println("recv ...");
    ia = InetAddress.getByName("localhost");//192.168.0.17"127.0.0.1"
    dsevent = new DataSwapEvent(this);
    SocketAddress sa = new InetSocketAddress(ia,
    DatagramRecvSender_s.DatagramPort);
    //至少要指定数据报接收端口,这是对接收端的唯一要求.当然假如主机是多址主机,需要road = new DatagramSocket(sa);
    road = new DatagramSocket(DatagramRecvSender_s.DatagramPort);
    System.out.println(road.isBound()+"::"+road.getBroadcast());
   }
   catch (SocketException ex) {
    ex.printStackTrace();
   }
   catch (Exception ex1) {
    ex1.printStackTrace();
   }
  }
  /**
  * 这个构造器用于发送数据报.
  * @param send String
  */
  public DatagramRecvSender_s(String send) {
   try {
    System.out.println("start sending ...");
    ia = InetAddress.getByName("192.168.0.4");//"255.255.255.255""192.168.0.4""127.0.0.1"
    dsevent = new DataSwapEvent(this);
    SocketAddress sa = new InetSocketAddress(ia,
    DatagramRecvSender_s.DatagramPort);
    //假如需要接收数据报,就需要指定一个端口,否则不必指定.road = new DatagramSocket(DatagramRecvSender_s.DatagramPort-1);
    road = new DatagramSocket();
    System.out.println("isBound--"+road.isBound()+":getBroadcast--"+road.getBroadcast());
   }
   catch (SocketException ex) {
    ex.printStackTrace();
   }
   catch (UnknownHostException ex1) {
    ex1.printStackTrace();
   }
  }
  public void sendFile(String file) {
   cdp = new DataPacket(file);
   System.out.println(file);
   Iterator it = cdp.getDataPackets().iterator();
   byte[] b;
   while (it.hasNext()) {
    b = ( (DataEntry) it.next()).getByte();
    //数据报是自包含的,自描述的数据,它的投递是由路由器执行的,路由器路由算法根据报文的目标地址选择适当的路由递送报文,
    //所以数据报中要指定目标ip地址和目标主机处理端口.
    DatagramPacket dp = new DatagramPacket(b, 0, b.length, ia,DatagramRecvSender_s.DatagramPort);
    try {
     Thread. sleep (100);
     if(dp==null)
      continue;
     road.send(dp);
    }
    catch (Exception ex) {
     ex.printStackTrace();
    }
   }
  }
  public boolean isHandling() {
   return ishandling;
  }
  public void isHandling(boolean ishand) {
   ishandling = ishand;
  }
  public void run() {
   byte[] buffer = new byte[DataPacket.DataSwapSize];
   DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
   DataPacket dp = new DataPacket();
   while (ishandling) {
    packet.setLength(buffer.length);
    System.out.println("wait .. ");
    try {
     road.receive(packet);
     dp.Add(packet.getData());
     if (dp.isFull()) {
      dsevent.setImage(dp.Gereratedata());
      this.processRecvFinishedEvent(dsevent);
      dp = new DataPacket();
     }
    }
    catch (IOException ex) {
     System.out.println(ex);
    }
   }
  }
  public static void main(String[] args) {
   String file[];
   ArrayList al = new ArrayList();
   String path = "E:\\nature\\";
   File f = new File(path);
   file = f.list();
   DatagramRecvSender_s dgrs = new DatagramRecvSender_s("");
   for(int j=0;j <1000;j++)
    for (int i = 0; i < file.length; i++) {
     try {
      Thread.sleep(2000);
     }
     catch (InterruptedException ex) {
     }
     if (file[i].endsWith("jpg") file[i].endsWith("bmp"))
      dgrs.sendFile(path + file[i]);
    }
   }
  }

  下面看接收端的界面.
package recmail.multiservice;
import java.awt.BorderLayout;
public class testDual
extends DualWindow implements DataSwapListener {
  JImagePanel ip;
  java.awt.Image bi;
  public testDual() {}
  public void init() {
   super.init();
   ImageShow is = new ImageShow();
   is.addDataSwapListener(this);
   Thread thread = new Thread(is, "test");
   thread.start();
  }
  public static void main(String[] args) {
   testDual test = new testDual();
   test.initmain();
   test.go();
   DatagramRecvSender_s dgrs = new DatagramRecvSender_s();
   dgrs.addDataSwapListener(test);
   Thread thread = new Thread(dgrs, "test");
   thread.start();
  }
  public void initmain() {
   super.initmain();
   ip = new JImagePanel();
   root.setLayout(new BorderLayout(5, 5));
   root.add(ip, BorderLayout.CENTER);
  }
  public void OnDataSendFinished(Object s, DataSwapEvent e) {}
  public void OnDataRecvFinished(Object s, DataSwapEvent e) {
   this.bi = e.getImage();
   ip.setImage(bi);
   System.out.println("recv Finished!

Tags:利用 Java

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