Java tutorial
/** * This file is part of Ogar. * * Ogar 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. * * Ogar 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 Ogar. If not, see <http://www.gnu.org/licenses/>. */ package ru.calypso.ogar.server.net; import java.nio.ByteOrder; import java.util.List; import org.apache.log4j.Logger; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.MessageToMessageDecoder; import io.netty.handler.codec.http.websocketx.WebSocketFrame; import ru.calypso.ogar.server.net.packet.Packet; import ru.calypso.ogar.server.net.packet.PacketRegistry; import ru.calypso.ogar.server.util.Log; public class PacketDecoder extends MessageToMessageDecoder<WebSocketFrame> { private static Logger _log = Logger.getLogger(PacketDecoder.class); @Override protected void decode(ChannelHandlerContext ctx, WebSocketFrame frame, List<Object> out) throws Exception { ByteBuf buf = frame.content().order(ByteOrder.LITTLE_ENDIAN); if (buf.capacity() < 1) { // Discard empty messages return; } buf.resetReaderIndex(); int packetId = buf.readUnsignedByte(); Packet packet = PacketRegistry.CLIENT2SERVER.constructPacket(packetId); if (packet == null) { _log.info("Unknown packet ID: " + packetId + ", user disconected!"); ctx.disconnect(); return; } Log.logDebug("Received packet ID " + packetId + " (" + packet.getClass().getSimpleName() + ") from " + ctx.channel().remoteAddress()); packet.readData(buf); out.add(packet); } }