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root/i-scream/experimental/server/XMLReader/UDPReader.java
Revision: 1.3
Committed: Fri Nov 17 15:25:48 2000 UTC (23 years, 5 months ago) by pjm2
Branch: MAIN
Changes since 1.2: +10 -1 lines
Log Message:
Wrapped the DatagramSocket part in a try { } so that a warning is given
when some other process is already listening on the same port.

File Contents

# User Rev Content
1 pjm2 1.1 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 {
10    
11     public static void main(String[] args) throws IOException {
12    
13 pjm2 1.2 // default UDP listening port.
14     int port = 4589;
15     final int packetSizeLimit = 8192;
16 pjm2 1.1
17 pjm2 1.2 // Allow the user to choose their own port number.
18     if (args.length == 1){
19     try {
20     port = new Integer(args[0]).intValue();
21     }
22     catch (Exception e){
23     // If something went wrong, use the default again.
24     port = 4589;
25     }
26     }
27    
28 pjm2 1.3 DatagramSocket socket = null;
29     try {
30     socket = new DatagramSocket(port);
31     }
32     catch (BindException e){
33     System.out.println("Some other process is already listening on port "+port+".");
34     System.out.println("Please specify another port number on the command line.");
35     System.exit(0);
36     }
37    
38 pjm2 1.2 System.out.println("UDPReader ready and listening for UDP packets on port "+port);
39    
40     boolean running = true;
41     while (running){
42     try {
43     byte[] buf = new byte[packetSizeLimit];
44 pjm2 1.1 // receive request
45 pjm2 1.2 DatagramPacket packet = new DatagramPacket(buf, buf.length);
46     socket.receive(packet);
47     UDPReaderThread thread = new UDPReaderThread(packet);
48     thread.run();
49     }
50     catch (IOException e) {
51     System.out.println("An exception occured in the UDPReader!");
52     e.printStackTrace();
53     }
54 pjm2 1.1 }
55     socket.close();
56     }
57     }