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/*
* Copyright 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 java.nio.charset.Charset;
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;
public class H02FrameDecoder extends FrameDecoder {
private static final int MESSAGE_LENGTH = 32;
@Override
protected Object decode(
ChannelHandlerContext ctx,
Channel channel,
ChannelBuffer buf) throws Exception {
String marker = buf.toString(buf.readerIndex(), 1, Charset.defaultCharset());
while (!marker.equals("*") && !marker.equals("$") && buf.readableBytes() > 0) {
buf.skipBytes(1);
if (buf.readableBytes() > 0) {
marker = buf.toString(buf.readerIndex(), 1, Charset.defaultCharset());
}
}
if (marker.equals("*")) {
// Return text message
Integer index = ChannelBufferTools.find(buf, buf.readerIndex(), buf.readableBytes(), "#");
if (index != null) {
return buf.readBytes(index + 1 - buf.readerIndex());
}
} else if (marker.equals("$")) {
// Return binary message
if (buf.readableBytes() >= MESSAGE_LENGTH) {
return buf.readBytes(MESSAGE_LENGTH);
}
}
return null;
}
}
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