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/*
* Copyright 2012 - 2013 Anton Tananaev (anton.tananaev@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;
import org.traccar.helper.ChannelBufferTools;
import org.traccar.helper.StringFinder;
public class XexunFrameDecoder extends FrameDecoder {
@Override
protected Object decode(
ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
if (buf.readableBytes() < 80) {
return null;
}
int beginIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), new StringFinder("GPRMC"));
if (beginIndex == -1) {
beginIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), new StringFinder("GNRMC"));
if (beginIndex == -1) {
return null;
}
}
int identifierIndex = buf.indexOf(beginIndex, buf.writerIndex(), new StringFinder("imei:"));
if (identifierIndex == -1) {
return null;
}
int endIndex = buf.indexOf(identifierIndex, buf.writerIndex(), (byte) ',');
if (endIndex == -1) {
return null;
}
buf.skipBytes(beginIndex);
return buf.readBytes(endIndex - beginIndex + 1);
}
}
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