--- experimental/server/XMLReader/UDPReader.java	2000/11/17 12:16:39	1.2
+++ experimental/server/XMLReader/UDPReader.java	2000/11/21 09:38:27	1.7
@@ -3,40 +3,51 @@ import java.net.*;
 import java.util.*;
 
 // This class contains the main method to be run by
-// the filter children.  It harvests UDP traffic
+// the filter children.  It harvests UDP traffic.
 //
 //
-public class UDPReader {
+public class UDPReader extends Thread{
 
-    public static void main(String[] args) throws IOException {
+    // It is normal to use this constructor in preference
+    // to any other in this class.
+    public UDPReader(int port, Logger logger){
+        this.logger = logger;
+        this.port = port;
+    }
+    
+    public UDPReader(Logger logger){
+        this(4589, logger);
+    }
 
-        // default UDP listening port.
-        int port = 4589;
-        final int packetSizeLimit = 8192;
+    public void run() {
 
-        // Allow the user to choose their own port number.
-        if (args.length == 1){
-            try {
-                port = new Integer(args[0]).intValue();
-            }
-            catch (Exception e){
-                // If something went wrong, use the default again.
-                port = 4589;
-            }
+        DatagramSocket socket = null;
+        try {
+            socket = new DatagramSocket(port);
         }
-
-        DatagramSocket socket = new DatagramSocket(port);
+        catch (BindException e){
+            System.out.println("Some other process is already listening on port "+port+".");
+            System.out.println("Please specify another port number on the command line.");
+            return;
+        }
+        catch (Exception e){
+            System.out.println("An exception occured while creating the DatagramSocket.");
+            return;
+        }
+        
         System.out.println("UDPReader ready and listening for UDP packets on port "+port);
 
+        byte[] buf;
+        
         boolean running = true;
         while (running){
             try {
-                byte[] buf = new byte[packetSizeLimit];
+                buf = new byte[packetSizeLimit];
                 // receive request
                 DatagramPacket packet = new DatagramPacket(buf, buf.length);
                 socket.receive(packet);
-                UDPReaderThread thread = new UDPReaderThread(packet);
-                thread.run();
+                UDPReaderThread t = new UDPReaderThread();
+                t.run(packet);
             }
             catch (IOException e) {
                 System.out.println("An exception occured in the UDPReader!");
@@ -45,4 +56,11 @@ public class UDPReader {
         }
         socket.close();
     }
+    
+    
+    Logger logger;
+    int port;
+    
+    final int packetSizeLimit = 8192;
+    
 }