UDP receiving works in non-blocking mode until it's not cancelled.

This allows to receive any number of datagrams.

Author: reicru

netcat/src/main/java/com/github/dddpaul/netcat/NetCat.java

@@ -7,6 +7,9 @@
 
 import de.greenrobot.event.EventBus;
 import events.ActivityEvent;
+import events.FragmentEvent;
+
+import static com.github.dddpaul.netcat.NetCater.Op.*;
 
 public class NetCat implements NetCater
 {
@@ -104,6 +107,9 @@ protected void onProgressUpdate( String... values )
         {
             State state = State.valueOf( String.valueOf( values[0] ) );
             EventBus.getDefault().post( new ActivityEvent( state ) );
+            if( values.length == 2 ) {
+                EventBus.getDefault().post( new FragmentEvent( HANDLE_RECEIVED_DATA, values[1] ));
+            }
         }
 
         @Override

netcat/src/main/java/com/github/dddpaul/netcat/NetCater.java

@@ -10,8 +10,8 @@
 
 public interface NetCater
 {
-    enum Op { CONNECT, LISTEN, RECEIVE, SEND, DISCONNECT, CLEAR_OUTPUT_VIEW }
-    enum State { IDLE, CONNECTED, LISTENING, OUTPUT_VIEW_CLEARED, CONNECTING}
+    enum Op { CONNECT, LISTEN, RECEIVE, SEND, DISCONNECT, CLEAR_OUTPUT_VIEW, HANDLE_RECEIVED_DATA}
+    enum State { IDLE, CONNECTED, LISTENING, OUTPUT_VIEW_CLEARED, CONNECTING }
     enum Proto { TCP, UDP }
 
     public void cancel();

netcat/src/main/java/com/github/dddpaul/netcat/UdpNetCat.java

@@ -10,6 +10,8 @@
 import java.nio.channels.AsynchronousCloseException;
 import java.nio.channels.DatagramChannel;
 
+import static com.github.dddpaul.netcat.NetCater.State.CONNECTED;
+
 public class UdpNetCat extends NetCat
 {
     private final String CLASS_NAME = getClass().getSimpleName();
@@ -73,6 +75,8 @@ protected Result doInBackground( String... params )
                         Log.d( CLASS_NAME, String.format( "Connecting to %s:%d (UDP)", host, port ) );
                         channel = DatagramChannel.open();
                         channel.connect( new InetSocketAddress( host, port ) );
+                        channel.configureBlocking( false );
+                        Log.i( CLASS_NAME, "Connected to " + channel.socket().getRemoteSocketAddress() );
                         result.object = channel.socket();
                         break;
                     case LISTEN:
@@ -121,12 +125,14 @@ private SocketAddress receiveFromChannel() throws Exception
             try {
                 ByteBuffer buf = ByteBuffer.allocate( 1024 );
                 buf.clear();
-                while( remoteSocketAddress == null && !task.isCancelled() ) {
+                while( !task.isCancelled() ) {
                     remoteSocketAddress = channel.receive( buf );
-                    Thread.sleep( 100 );
-                }
-                if( remoteSocketAddress != null ) {
-                    output.write( buf.array(), 0, buf.position() );
+                    if( remoteSocketAddress != null ) {
+                        Log.d( CLASS_NAME, String.format( "%d bytes was received from %s", buf.position() - 1, remoteSocketAddress ));
+                        output.write( buf.array(), 0, buf.position() );
+                        publishProgress( CONNECTED.toString(), output.toString() );
+                    }
+                    Thread.sleep( 1000 );
                 }
                 if( task.isCancelled() ) {
                     stopListening();

netcat/src/main/java/com/github/dddpaul/netcat/ui/ResultFragment.java

@@ -174,6 +174,9 @@ public void onEvent( FragmentEvent event )
                     netCat.cancel();
                 }
                 break;
+            case HANDLE_RECEIVED_DATA:
+                outputView.setText( event.data );
+                break;
             case CLEAR_OUTPUT_VIEW:
                 outputView.setText( "" );
                 EventBus.getDefault().post( new ActivityEvent( OUTPUT_VIEW_CLEARED ) );