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Diffstat (limited to 'src/org/traccar/protocol/Arnavi4FrameDecoder.java')
-rw-r--r--src/org/traccar/protocol/Arnavi4FrameDecoder.java74
1 files changed, 74 insertions, 0 deletions
diff --git a/src/org/traccar/protocol/Arnavi4FrameDecoder.java b/src/org/traccar/protocol/Arnavi4FrameDecoder.java
new file mode 100644
index 000000000..b13f3fd7d
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+++ b/src/org/traccar/protocol/Arnavi4FrameDecoder.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2017 Ivan Muratov (binakot@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;
+
+public class Arnavi4FrameDecoder extends FrameDecoder {
+
+ private static final int MIN_LENGTH = 4;
+ private static final int HEADER_LENGTH = 10;
+ private static final int PACKET_WRAPPER_LENGTH = 8;
+ private static final int COMMAND_ANSWER_PACKET_LENGTH = 4;
+ private static final int COMMAND_ANSWER_PARCEL_NUMBER = 0xfd;
+ private static final byte PACKAGE_END_SIGN = 0x5d;
+
+ private boolean firstPacket = true;
+
+ @Override
+ protected Object decode(
+ ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
+
+ if (buf.readableBytes() < MIN_LENGTH) {
+ return null;
+ }
+
+ int length;
+ if (firstPacket) {
+ firstPacket = false;
+ length = HEADER_LENGTH;
+ } else {
+ int index = buf.getUnsignedByte(1); // parcel number
+ if (index == COMMAND_ANSWER_PARCEL_NUMBER) {
+ length = COMMAND_ANSWER_PACKET_LENGTH;
+ } else {
+ int pos = 2; // start sign + parcel number
+ while (pos + PACKET_WRAPPER_LENGTH < buf.readableBytes()
+ && buf.getByte(pos) != PACKAGE_END_SIGN) {
+
+ int dataLength = buf.getUnsignedShort(pos + 1);
+ pos += PACKET_WRAPPER_LENGTH + dataLength; // packet type + data length + unixtime + data + crc
+ }
+
+ if (buf.getByte(pos) != PACKAGE_END_SIGN) { // end sign
+ return null;
+ }
+
+ length = pos + 1;
+ }
+ }
+
+ if (buf.readableBytes() >= length) {
+ return buf.readBytes(length);
+ }
+
+ return null;
+ }
+
+}