1 files changed, 50 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/AlematicsFrameDecoder.java b/src/main/java/org/traccar/protocol/AlematicsFrameDecoder.java
new file mode 100644
index 000000000..be7666657
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/AlematicsFrameDecoder.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ *
+ * 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 io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import org.traccar.NetworkMessage;
+
+public class AlematicsFrameDecoder extends LineBasedFrameDecoder {
+
+    private static final int MESSAGE_MINIMUM_LENGTH = 2;
+
+    public AlematicsFrameDecoder(int maxFrameLength) {
+        super(maxFrameLength);
+    }
+
+    // example of heartbeat: FA F8 00 07 00 03 15 AD 4E 78 3A D2
+
+    @Override
+    protected Object decode(ChannelHandlerContext ctx, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() < MESSAGE_MINIMUM_LENGTH) {
+            return null;
+        }
+
+        if (buf.getUnsignedShort(buf.readerIndex()) == 0xFAF8) {
+            ByteBuf heartbeat = buf.readRetainedSlice(12);
+            if (ctx != null && ctx.channel() != null) {
+                ctx.channel().writeAndFlush(new NetworkMessage(heartbeat, ctx.channel().remoteAddress()));
+            }
+        }
+
+        return super.decode(ctx, buf);
+    }
+
+}