multicastserverthread.java

《Java TCP/IP应用开发详解》的部分源程序,开发环境为ECLIPSE3.1

package section20;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Date;


public class MulticastServerThread extends Thread {
    private long FIVE_SECONDS=5000;
    private boolean moreQuotes=true;
    DatagramSocket socket=null;
    private static BufferedReader in;
	public MulticastServerThread(DatagramSocket socket)throws IOException {
		super();
        this.socket=socket;		
        in=new BufferedReader(new FileReader("one-liners.txt"));
        
        // TODO Auto-generated constructor stub
	}

    public void run()
    {
    	while(moreQuotes)
    	{
    		try
    		{
    			byte[]buf=new byte[256];
    			String dString=null;
    			if(in==null)
    				dString=new Date().toString();
    			else
    				dString=getNextQuote();
    		    buf=dString.getBytes();
    			InetAddress group=InetAddress.getByName("230.0.0.1");
    			DatagramPacket packet=new DatagramPacket(buf,buf.length,group,1111);
    			socket.send(packet);
    			try{
    				sleep((long)(Math.random()*FIVE_SECONDS));
    				
    			}catch(InterruptedException e){}
    		}catch(IOException e)
    			  {
    				e.printStackTrace();
    			    moreQuotes=false;
    			  }
    		  
    		
    			}
    	socket.close();		
    }
    


    protected static String getNextQuote()
    {
    	
    	
    	String returnValue=null;
    	try{
    		if((returnValue=in.readLine())==null)
    		{
    			in.close();
    			returnValue="No more quotes.Goodbye.";
    		}
    	}catch(IOException e)
    	{
    		returnValue="IOException occurred in server";
    	}
    return returnValue;
    } 
    
    
}