Java tutorial
/******************************************************************************* * Copyright 2015 Peter Cashel (pacas00@petercashel.net) * * 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 net.petercashel.nettyCore.server; import java.net.SocketAddress; import net.petercashel.nettyCore.common.PacketRegistry; import net.petercashel.nettyCore.common.packetCore.IPacketBase; import net.petercashel.nettyCore.common.packetCore.Packet; import net.petercashel.nettyCore.common.packets.PingPacket; import net.petercashel.nettyCore.common.packets.PongPacket; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.timeout.ReadTimeoutException; import io.netty.util.ReferenceCountUtil; public class ServerConnectionHandler extends ChannelHandlerAdapter { private ByteBuf buf; @Override public void handlerAdded(ChannelHandlerContext ctx) { buf = ctx.alloc().buffer(Packet.packetBufSize + Packet.packetHeaderSize); // (1) } @Override public void handlerRemoved(ChannelHandlerContext ctx) { buf.release(); // (1) buf = null; } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { try { if (!(serverCore.clientConnectionMap.containsKey(ctx.channel().remoteAddress()))) { ChannelUserHolder chUser = (new ChannelUserHolder()); chUser.c = ctx.channel(); serverCore.clientConnectionMap.put(ctx.channel().remoteAddress(), chUser); } } catch (NullPointerException e) { // Delibrately null on shutdown. ctx.close(); ctx.executor().shutdownGracefully(); } } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { ByteBuf m = (ByteBuf) msg; buf.writeBytes(m); // (2) m.release(); if (buf.readableBytes() >= (Packet.packetBufSize + Packet.packetHeaderSize)) { // (3) int side = buf.readInt(); Packet p = new Packet(buf.readInt(), buf.readBytes(Packet.packetBufSize)); PacketRegistry.unpackExecute(p, ctx); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { serverCore.clientConnectionMap.remove(ctx.channel().remoteAddress().toString()); if (cause instanceof ReadTimeoutException) { System.out.println("Connection Timed Out: " + ctx.channel().remoteAddress().toString()); } else { super.exceptionCaught(ctx, cause); } } }