| 1 | import java.io.*; | 
 
 
 
 
 | 2 | import java.net.*; | 
 
 
 
 
 | 3 | import java.util.*; | 
 
 
 
 
 | 4 |  | 
 
 
 
 
 | 5 | // This class contains the main method to be run by | 
 
 
 
 
 | 6 | // the filter children.  It harvests UDP traffic. | 
 
 
 
 
 | 7 | // | 
 
 
 
 
 | 8 | // | 
 
 
 
 
 | 9 | public class UDPReader extends Thread{ | 
 
 
 
 
 | 10 |  | 
 
 
 
 
 | 11 | // It is normal to use this constructor in preference | 
 
 
 
 
 | 12 | // to any other in this class. | 
 
 
 
 
 | 13 | public UDPReader(int port, Logger logger){ | 
 
 
 
 
 | 14 | this.logger = logger; | 
 
 
 
 
 | 15 | this.port = port; | 
 
 
 
 
 | 16 | } | 
 
 
 
 
 | 17 |  | 
 
 
 
 
 | 18 | public UDPReader(Logger logger){ | 
 
 
 
 
 | 19 | this(4589, logger); | 
 
 
 
 
 | 20 | } | 
 
 
 
 
 | 21 |  | 
 
 
 
 
 | 22 | public void run() { | 
 
 
 
 
 | 23 |  | 
 
 
 
 
 | 24 | DatagramSocket socket = null; | 
 
 
 
 
 | 25 | try { | 
 
 
 
 
 | 26 | socket = new DatagramSocket(port); | 
 
 
 
 
 | 27 | } | 
 
 
 
 
 | 28 | catch (BindException e){ | 
 
 
 
 
 | 29 | System.out.println("Some other process is already listening on port "+port+"."); | 
 
 
 
 
 | 30 | System.out.println("Please specify another port number on the command line."); | 
 
 
 
 
 | 31 | return; | 
 
 
 
 
 | 32 | } | 
 
 
 
 
 | 33 | catch (Exception e){ | 
 
 
 
 
 | 34 | System.out.println("An exception occured while creating the DatagramSocket."); | 
 
 
 
 
 | 35 | return; | 
 
 
 
 
 | 36 | } | 
 
 
 
 
 | 37 |  | 
 
 
 
 
 | 38 | System.out.println("UDPReader ready and listening for UDP packets on port "+port); | 
 
 
 
 
 | 39 |  | 
 
 
 
 
 | 40 | byte[] buf; | 
 
 
 
 
 | 41 | UDPReaderThread t = new UDPReaderThread(); | 
 
 
 
 
 | 42 |  | 
 
 
 
 
 | 43 | boolean running = true; | 
 
 
 
 
 | 44 | while (running){ | 
 
 
 
 
 | 45 | try { | 
 
 
 
 
 | 46 | buf = new byte[packetSizeLimit]; | 
 
 
 
 
 | 47 | // receive request | 
 
 
 
 
 | 48 | DatagramPacket packet = new DatagramPacket(buf, buf.length); | 
 
 
 
 
 | 49 | socket.receive(packet); | 
 
 
 
 
 | 50 | t.run(packet); | 
 
 
 
 
 | 51 | } | 
 
 
 
 
 | 52 | catch (IOException e) { | 
 
 
 
 
 | 53 | System.out.println("An exception occured in the UDPReader!"); | 
 
 
 
 
 | 54 | e.printStackTrace(); | 
 
 
 
 
 | 55 | } | 
 
 
 
 
 | 56 | } | 
 
 
 
 
 | 57 | socket.close(); | 
 
 
 
 
 | 58 | } | 
 
 
 
 
 | 59 |  | 
 
 
 
 
 | 60 |  | 
 
 
 
 
 | 61 | Logger logger; | 
 
 
 
 
 | 62 | int port; | 
 
 
 
 
 | 63 |  | 
 
 
 
 
 | 64 | final int packetSizeLimit = 8192; | 
 
 
 
 
 | 65 |  | 
 
 
 
 
 | 66 | } |