server/filter/UDPReader.java

import java.io.*;
import java.net.*;
import java.util.*;
import uk.ac.ukc.iscream.core.*;
import uk.ac.ukc.iscream.filter.*;

// This class contains the main method to be run by
// the filter children.  It harvests UDP traffic.
//
public class UDPReader extends Thread{

    // It is normal to use this constructor in preference
    // to any other in this class.
    public UDPReader(int port, Filter parent, Logger logger){
        this.logger = logger;
        this.port = port;
        this.parent = parent;
    }
    
    public UDPReader(Filter parent, Logger logger){
        this(4589, parent, logger);
    }

    public void run() {

        DatagramSocket socket = null;
        try {
            socket = new DatagramSocket(port);
        }
        catch (BindException e){
            logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+port+" as this port was already in use.");
            return;
        }
        catch (Exception e){
            logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+port+".");
            return;
        }
        
        logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+port);

        byte[] buf;
        
        boolean running = true;
        while (running){
            try {

                    // receive request and pass on to the FilterThread.                
                buf = new byte[packetSizeLimit];
                DatagramPacket packet = new DatagramPacket(buf, buf.length);
                socket.receive(packet);
                FilterThread t = new FilterThread(packet, parent, logger);
                t.start();

            }
            catch (IOException e) {
                logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
                return;
            }
        }
        socket.close();
    }
    
    
    Logger logger;
    int port;
    Filter parent;    

    final int packetSizeLimit = 8192;
    
}
Revision:	1.5
Committed:	Thu Nov 23 09:21:48 2000 UTC (23 years, 5 months ago) by pjm2
Branch:	MAIN
Changes since 1.4:	+1 -1 lines
Log Message:	Altered both UDPReader and FilterThread such that a reference to a Logger is passed to the FilterThread when it is constructed.
#	User	Rev	Content
1	pjm2	1.1	import java.io.*;
2			import java.net.*;
3			import java.util.*;
4	tdb	1.2	import uk.ac.ukc.iscream.core.*;
5			import uk.ac.ukc.iscream.filter.*;
6	pjm2	1.1
7			// This class contains the main method to be run by
8			// the filter children. It harvests UDP traffic.
9			//
10			public class UDPReader extends Thread{
11
12			// It is normal to use this constructor in preference
13			// to any other in this class.
14	tdb	1.2	public UDPReader(int port, Filter parent, Logger logger){
15	pjm2	1.1	this.logger = logger;
16			this.port = port;
17	tdb	1.2	this.parent = parent;
18	pjm2	1.1	}
19
20	tdb	1.2	public UDPReader(Filter parent, Logger logger){
21			this(4589, parent, logger);
22	pjm2	1.1	}
23
24			public void run() {
25
26			DatagramSocket socket = null;
27			try {
28			socket = new DatagramSocket(port);
29			}
30			catch (BindException e){
31	pjm2	1.4	logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+port+" as this port was already in use.");
32	pjm2	1.1	return;
33			}
34			catch (Exception e){
35	pjm2	1.4	logger.write(this.toString(), Logger.FATAL, "Could not start the UDPReader thread on port "+port+".");
36	pjm2	1.1	return;
37			}
38
39			logger.write(this.toString(), Logger.SYSMSG, "UDPReader thread ready and listening for UDP packets on port "+port);
40
41			byte[] buf;
42
43			boolean running = true;
44			while (running){
45			try {
46	pjm2	1.3
47			// receive request and pass on to the FilterThread.
48	pjm2	1.1	buf = new byte[packetSizeLimit];
49			DatagramPacket packet = new DatagramPacket(buf, buf.length);
50			socket.receive(packet);
51	pjm2	1.5	FilterThread t = new FilterThread(packet, parent, logger);
52	pjm2	1.3	t.start();
53
54	pjm2	1.1	}
55			catch (IOException e) {
56	pjm2	1.4	logger.write(this.toString(), Logger.WARNING, "This UDPReader thread has been shut down as an exception occured: "+e);
57	pjm2	1.1	return;
58			}
59			}
60			socket.close();
61			}
62
63
64			Logger logger;
65			int port;
66	tdb	1.2	Filter parent;
67
68	pjm2	1.1	final int packetSizeLimit = 8192;
69
70			}