Java tutorial
/* * Copyright 2013-2018 Lilinfeng. * * 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 com.changxx.phei.netty.protocol.udp; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.channel.socket.DatagramPacket; import io.netty.util.CharsetUtil; import io.netty.util.internal.ThreadLocalRandom; /** * @author lilinfeng * @date 2014214 * @version 1.0 */ public class ChineseProverbServerHandler extends SimpleChannelInboundHandler<DatagramPacket> { // private static final String[] DICTIONARY = { "????", "?", "?", "", "????!" }; private String nextQuote() { int quoteId = ThreadLocalRandom.current().nextInt(DICTIONARY.length); return DICTIONARY[quoteId]; } @Override public void messageReceived(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception { String req = packet.content().toString(CharsetUtil.UTF_8); System.out.println(req); if ("?".equals(req)) { ctx.writeAndFlush(new DatagramPacket( Unpooled.copiedBuffer(": " + nextQuote(), CharsetUtil.UTF_8), packet.sender())); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { ctx.close(); cause.printStackTrace(); } }