blob: e14d8ed58c892114410ebf5992c21716deebd648 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
/*
* Copyright 2013 - 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.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import org.traccar.BaseFrameDecoder;
public class MeiligaoFrameDecoder extends BaseFrameDecoder {
private static final int MESSAGE_HEADER = 4;
@Override
protected Object decode(
ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
// Strip not '$' (0x24) bytes from the beginning
while (buf.isReadable() && buf.getUnsignedByte(buf.readerIndex()) != 0x24) {
buf.readByte();
}
// Check length and return buffer
if (buf.readableBytes() >= MESSAGE_HEADER) {
int length = buf.getUnsignedShort(buf.readerIndex() + 2);
if (buf.readableBytes() >= length) {
return buf.readBytes(length);
}
}
return null;
}
}
|
