Add option to save empty messages

1 files changed, 18 insertions, 9 deletions

diff --git a/src/org/traccar/ExtendedObjectDecoder.java b/src/org/traccar/ExtendedObjectDecoder.java
index 2734f5469..ded749e6c 100644
--- a/src/org/traccar/ExtendedObjectDecoder.java
+++ b/src/org/traccar/ExtendedObjectDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton.tananaev@gmail.com)
+ * Copyright 2015 - 2016 Anton Tananaev (anton.tananaev@gmail.com)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -59,15 +59,20 @@ public abstract class ExtendedObjectDecoder implements ChannelUpstreamHandler {
         onMessageEvent(e.getChannel(), e.getRemoteAddress(), originalMessage); // call after decode
         if (originalMessage == decodedMessage) {
             ctx.sendUpstream(evt);
-        } else if (decodedMessage != null) {
-            if (decodedMessage instanceof Collection) {
-                for (Object o : (Collection) decodedMessage) {
-                    saveOriginal(o, originalMessage);
-                    Channels.fireMessageReceived(ctx, o, e.getRemoteAddress());
+        } else {
+            if (decodedMessage == null) {
+                decodedMessage = handleEmptyMessage(e.getChannel(), e.getRemoteAddress(), originalMessage);
+            }
+            if (decodedMessage != null) {
+                if (decodedMessage instanceof Collection) {
+                    for (Object o : (Collection) decodedMessage) {
+                        saveOriginal(o, originalMessage);
+                        Channels.fireMessageReceived(ctx, o, e.getRemoteAddress());
+                    }
+                } else {
+                    saveOriginal(decodedMessage, originalMessage);
+                    Channels.fireMessageReceived(ctx, decodedMessage, e.getRemoteAddress());
                 }
-            } else {
-                saveOriginal(decodedMessage, originalMessage);
-                Channels.fireMessageReceived(ctx, decodedMessage, e.getRemoteAddress());
             }
         }
     }
@@ -75,6 +80,10 @@ public abstract class ExtendedObjectDecoder implements ChannelUpstreamHandler {
     protected void onMessageEvent(Channel channel, SocketAddress remoteAddress, Object msg) {
     }
 
+    protected Object handleEmptyMessage(Channel channel, SocketAddress remoteAddress, Object msg) {
+        return null;
+    }
+
     protected abstract Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception;
 
 }