1 files changed, 48 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java b/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java
new file mode 100644
index 000000000..52d43c36c
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2022 Stefan Clark (stefan@stefanclark.co.uk)
+ *
+ * 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.MessageToByteEncoder;
+
+public class Xexun2FrameEncoder extends MessageToByteEncoder<ByteBuf> {
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out) {
+        out.writeBytes(msg.readBytes(2));
+
+        while (msg.readableBytes() > 2) {
+            int b = msg.readUnsignedByte();
+            if (b == 0xfa && msg.isReadable() && msg.getUnsignedByte(msg.readerIndex()) == 0xaf) {
+                msg.readUnsignedByte();
+                out.writeByte(0xfb);
+                out.writeByte(0xbf);
+                out.writeByte(0x01);
+            } else if (b == 0xfb && msg.isReadable() && msg.getUnsignedByte(msg.readerIndex()) == 0xbf) {
+                msg.readUnsignedByte();
+                out.writeByte(0xfb);
+                out.writeByte(0xbf);
+                out.writeByte(0x02);
+            } else {
+                out.writeByte(b);
+            }
+        }
+
+        out.writeBytes(msg.readBytes(2));
+
+    }
+}