Implement custom Watch frame decoder

2 files changed, 48 insertions, 2 deletions

diff --git a/src/org/traccar/protocol/WatchFrameDecoder.java b/src/org/traccar/protocol/WatchFrameDecoder.java
new file mode 100644
index 000000000..b02048079
--- /dev/null
+++ b/src/org/traccar/protocol/WatchFrameDecoder.java
@@ -0,0 +1,46 @@
+/*
+ * 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 org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelHandlerContext;
+import org.jboss.netty.handler.codec.frame.FrameDecoder;
+
+import java.nio.charset.StandardCharsets;
+
+public class WatchFrameDecoder extends FrameDecoder {
+
+    private static final int MESSAGE_HEADER = 20;
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
+
+        if (buf.readableBytes() >= MESSAGE_HEADER) {
+            ChannelBuffer lengthBuffer = ChannelBuffers.dynamicBuffer();
+            buf.getBytes(buf.readerIndex() + MESSAGE_HEADER - 4 - 1, lengthBuffer, 4);
+            int length = Integer.parseInt(lengthBuffer.toString(StandardCharsets.US_ASCII), 16) + MESSAGE_HEADER + 1;
+            if (buf.readableBytes() >= length) {
+                return buf.readBytes(length);
+            }
+        }
+
+        return null;
+    }
+
+}
diff --git a/src/org/traccar/protocol/WatchProtocol.java b/src/org/traccar/protocol/WatchProtocol.java
index f664691c3..72a260423 100644
--- a/src/org/traccar/protocol/WatchProtocol.java
+++ b/src/org/traccar/protocol/WatchProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 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.
@@ -51,7 +51,7 @@ public class WatchProtocol extends BaseProtocol {
         serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
             @Override
             protected void addSpecificHandlers(ChannelPipeline pipeline) {
-                pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, ']'));
+                pipeline.addLast("frameDecoder", new WatchFrameDecoder());
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("objectEncoder", new WatchProtocolEncoder());