3 files changed, 69 insertions, 1 deletions
diff --git a/src/org/traccar/ServerManager.java b/src/org/traccar/ServerManager.java
index 25ef3177a..897642551 100644
--- a/src/org/traccar/ServerManager.java
+++ b/src/org/traccar/ServerManager.java
@@ -849,7 +849,7 @@ public class ServerManager {
             serverList.add(new TrackerServer(this, new ServerBootstrap(), protocol) {
                 @Override
                 protected void addSpecificHandlers(ChannelPipeline pipeline) {
-                    pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(1024, 4, 2, 6, 0));
+                    pipeline.addLast("frameDecoder", new AtrackFrameDecoder());
                     pipeline.addLast("objectDecoder", new AtrackProtocolDecoder(ServerManager.this));
                 }
             });
diff --git a/src/org/traccar/protocol/AtrackFrameDecoder.java b/src/org/traccar/protocol/AtrackFrameDecoder.java
new file mode 100644
index 000000000..970ddc66b
--- /dev/null
+++ b/src/org/traccar/protocol/AtrackFrameDecoder.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2013 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelHandlerContext;
+import org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder;
+
+public class AtrackFrameDecoder extends LengthFieldBasedFrameDecoder {
+
+    private static final int KEEPALIVE_LENGTH = 12;
+    
+    public AtrackFrameDecoder() {
+        super(1024, 4, 2, 6, 0);
+    }
+    
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx,
+            Channel channel,
+            ChannelBuffer buf) throws Exception {
+        
+        // Keep alive message
+        if (buf.readableBytes() >= KEEPALIVE_LENGTH ||
+            buf.getUnsignedShort(buf.readerIndex()) == 0xfe02) {
+            channel.write(buf.readBytes(KEEPALIVE_LENGTH));
+        }
+
+        return super.decode(ctx, channel, buf);
+    }
+
+}
diff --git a/test/org/traccar/protocol/AtrackProtocolDecoderTest.java b/test/org/traccar/protocol/AtrackProtocolDecoderTest.java
new file mode 100644
index 000000000..c0d146153
--- /dev/null
+++ b/test/org/traccar/protocol/AtrackProtocolDecoderTest.java
@@ -0,0 +1,22 @@
+package org.traccar.protocol;
+
+import org.jboss.netty.buffer.ChannelBuffers;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import org.junit.Test;
+import org.traccar.helper.ChannelBufferTools;
+
+public class AtrackProtocolDecoderTest {
+
+    @Test
+    public void testDecode() throws Exception {
+
+        AtrackProtocolDecoder decoder = new AtrackProtocolDecoder(null);
+        decoder.setDataManager(new TestDataManager());
+
+        int[] buf1 = {0xfe,0x02,0x00,0x01,0x41,0x04,0xd8,0xf1,0x96,0x82,0x00,0x01};
+        assertNotNull(decoder.decode(null, null, ChannelBuffers.wrappedBuffer(ChannelBufferTools.convertArray(buf1))));
+
+    }
+
+}