Java tutorial
/** * This file is part of Waarp Project. * * Copyright 2009, Frederic Bregier, and individual contributors by the @author tags. See the * COPYRIGHT.txt in the distribution for a full listing of individual contributors. * * All Waarp Project is free software: you can redistribute it and/or modify it under the terms of * the GNU General Public License as published by the Free Software Foundation, either version 3 of * the License, or (at your option) any later version. * * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General * Public License for more details. * * You should have received a copy of the GNU General Public License along with Waarp . If not, see * <http://www.gnu.org/licenses/>. */ package org.waarp.openr66.protocol.localhandler.packet; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import org.waarp.openr66.protocol.exception.OpenR66ProtocolPacketException; import org.waarp.openr66.protocol.localhandler.LocalChannelReference; /** * Keep Alive class * * header = empty middle = way end = empty * * @author frederic bregier */ public class KeepAlivePacket extends AbstractLocalPacket { private static final byte ASKVALIDATE = 0; private static final byte ANSWERVALIDATE = 1; private byte way; /** * @param headerLength * @param middleLength * @param endLength * @param buf * @return the new EndTransferPacket from buffer * @throws OpenR66ProtocolPacketException */ public static KeepAlivePacket createFromBuffer(int headerLength, int middleLength, int endLength, ByteBuf buf) throws OpenR66ProtocolPacketException { if (middleLength != 1) { throw new OpenR66ProtocolPacketException("Not enough data"); } byte valid = buf.readByte(); return new KeepAlivePacket(valid); } /** * @param valid */ private KeepAlivePacket(byte valid) { way = valid; } /** */ public KeepAlivePacket() { way = ASKVALIDATE; } @Override public void createEnd(LocalChannelReference lcr) { end = Unpooled.EMPTY_BUFFER; } @Override public void createHeader(LocalChannelReference lcr) { header = Unpooled.EMPTY_BUFFER; } @Override public void createMiddle(LocalChannelReference lcr) { byte[] newbytes = { way }; middle = Unpooled.wrappedBuffer(newbytes); } @Override public byte getType() { return LocalPacketFactory.KEEPALIVEPACKET; } @Override public String toString() { return "KeepAlivePacket: " + way; } /** * @return True if this packet is to be validated */ public boolean isToValidate() { return way == ASKVALIDATE; } /** * Validate the connection */ public void validate() { way = ANSWERVALIDATE; header = null; middle = null; end = null; } }