1 files changed, 67 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/WatchFrameDecoder.java b/src/main/java/org/traccar/protocol/WatchFrameDecoder.java
new file mode 100644
index 000000000..f99bd52e2
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/WatchFrameDecoder.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2017 - 2018 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.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
+
+public class WatchFrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        int endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) ']') + 1;
+        if (endIndex > 0) {
+            ByteBuf frame = Unpooled.buffer();
+            while (buf.readerIndex() < endIndex) {
+                byte b1 = buf.readByte();
+                if (b1 == '}') {
+                    byte b2 = buf.readByte();
+                    switch (b2) {
+                        case 0x01:
+                            frame.writeByte('}');
+                            break;
+                        case 0x02:
+                            frame.writeByte('[');
+                            break;
+                        case 0x03:
+                            frame.writeByte(']');
+                            break;
+                        case 0x04:
+                            frame.writeByte(',');
+                            break;
+                        case 0x05:
+                            frame.writeByte('*');
+                            break;
+                        default:
+                            throw new IllegalArgumentException(String.format(
+                                    "unexpected byte at %d: 0x%02x", buf.readerIndex() - 1, b2));
+                    }
+                } else {
+                    frame.writeByte(b1);
+                }
+            }
+            return frame;
+        }
+
+        return null;
+    }
+
+}