Java tutorial
/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.controller.netconf.util.handler; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.ByteToMessageDecoder; import java.util.List; import org.opendaylight.controller.netconf.util.messages.FramingMechanism; import org.opendaylight.controller.netconf.util.messages.NetconfMessageConstants; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class NetconfMessageAggregator extends ByteToMessageDecoder { private final static Logger logger = LoggerFactory.getLogger(NetconfMessageAggregator.class); private byte[] eom = NetconfMessageConstants.endOfMessage; public NetconfMessageAggregator(FramingMechanism framingMechanism) { if (framingMechanism == FramingMechanism.CHUNK) { eom = NetconfMessageConstants.endOfChunk; } } @Override protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception { int index = indexOfSequence(in, eom); if (index == -1) { logger.debug("Message is not complete, read again."); ctx.read(); } else { ByteBuf msg = in.readBytes(index); in.readBytes(eom.length); in.discardReadBytes(); logger.debug("Message is complete."); out.add(msg); } } private int indexOfSequence(ByteBuf in, byte[] sequence) { int index = -1; for (int i = 0; i < in.readableBytes() - sequence.length + 1; i++) { if (in.getByte(i) == sequence[0]) { index = i; for (int j = 1; j < sequence.length; j++) { if (in.getByte(i + j) != sequence[j]) { index = -1; break; } } if (index != -1) { return index; } } } return index; } }