/*
* Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org)
* Copyright 2015 Vitaly Litvak (vitavaque@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 AutoFonFrameDecoder extends FrameDecoder {
@Override
protected Object decode(
ChannelHandlerContext ctx,
Channel channel,
ChannelBuffer buf) throws Exception {
// Check minimum length
if (buf.readableBytes() < 12) {
return null;
}
int length;
switch (buf.getUnsignedByte(buf.readerIndex())) {
case AutoFonProtocolDecoder.MSG_LOGIN:
length = 12;
break;
case AutoFonProtocolDecoder.MSG_LOCATION:
length = 78;
break;
case AutoFonProtocolDecoder.MSG_HISTORY:
length = 257;
break;
case AutoFonProtocolDecoder.MSG_45_LOGIN:
length = 19;
break;
case AutoFonProtocolDecoder.MSG_45_LOCATION:
length = 34;
break;
default:
length = 0;
break;
}
// Check length and return buffer
if (length != 0 && buf.readableBytes() >= length) {
return buf.readBytes(length);
}
return null;
}
}