Support Wondex keep alive (fix #380)

1 files changed, 60 insertions, 0 deletions

diff --git a/src/org/traccar/protocol/WondexFrameDecoder.java b/src/org/traccar/protocol/WondexFrameDecoder.java
new file mode 100644
index 000000000..7ef5cc376
--- /dev/null
+++ b/src/org/traccar/protocol/WondexFrameDecoder.java
@@ -0,0 +1,60 @@
+/*
+ * 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.FrameDecoder;
+import org.traccar.helper.ChannelBufferTools;
+
+public class WondexFrameDecoder extends FrameDecoder {
+    
+    private static final int KEEP_ALIVE_LENGTH = 6;
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx,
+            Channel channel,
+            ChannelBuffer buf) throws Exception {
+        
+        if (buf.readableBytes() < KEEP_ALIVE_LENGTH) {
+            return null;
+        }
+
+        if (buf.getUnsignedByte(buf.readerIndex()) == 0xD0) {
+
+            // Send response
+            ChannelBuffer frame = buf.readBytes(KEEP_ALIVE_LENGTH);
+            if (channel != null) {
+                channel.write(frame);
+            }
+
+        } else {
+
+            Integer index = ChannelBufferTools.find(buf, buf.readerIndex(), buf.readableBytes(), "\r\n");
+            if (index != null) {
+                ChannelBuffer frame = buf.readBytes(index - buf.readerIndex());
+                buf.skipBytes(2);
+                return frame;
+            }
+        
+        }
+
+        return null;
+    }
+
+}