| 1 |
import java.io.*; |
| 2 |
import java.net.*; |
| 3 |
import java.util.*; |
| 4 |
import uk.ac.ukc.iscream.core.*; |
| 5 |
import uk.ac.ukc.iscream.filter.*; |
| 6 |
|
| 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 |
public UDPReader(int port, Filter parent, Logger logger){ |
| 15 |
this.logger = logger; |
| 16 |
this.port = port; |
| 17 |
this.parent = parent; |
| 18 |
} |
| 19 |
|
| 20 |
public UDPReader(Filter parent, Logger logger){ |
| 21 |
this(4589, parent, logger); |
| 22 |
} |
| 23 |
|
| 24 |
public void run() { |
| 25 |
|
| 26 |
DatagramSocket socket = null; |
| 27 |
try { |
| 28 |
socket = new DatagramSocket(port); |
| 29 |
} |
| 30 |
catch (BindException e){ |
| 31 |
logger.write(this.toString(), Logger.SYSMSG, "Could not start the UDPReader thread on port "+port+" as this port was already in use."); |
| 32 |
return; |
| 33 |
} |
| 34 |
catch (Exception e){ |
| 35 |
logger.write(this.toString(), Logger.SYSMSG, "Could not start the UDPReader thread on port "+port+"."); |
| 36 |
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 |
|
| 47 |
// receive request and pass on to the FilterThread. |
| 48 |
buf = new byte[packetSizeLimit]; |
| 49 |
DatagramPacket packet = new DatagramPacket(buf, buf.length); |
| 50 |
socket.receive(packet); |
| 51 |
FilterThread t = new FilterThread(parent, packet); |
| 52 |
t.start(); |
| 53 |
|
| 54 |
} |
| 55 |
catch (IOException e) { |
| 56 |
logger.write(this.toString(), Logger.SYSMSG, "The UDPReader thread has been shut down as an exception occured: "+e); |
| 57 |
return; |
| 58 |
} |
| 59 |
} |
| 60 |
socket.close(); |
| 61 |
} |
| 62 |
|
| 63 |
|
| 64 |
Logger logger; |
| 65 |
int port; |
| 66 |
Filter parent; |
| 67 |
|
| 68 |
final int packetSizeLimit = 8192; |
| 69 |
|
| 70 |
} |
