com.lampard.netty4.protocol.udp.ChineseProverbServerHandler.java Source code

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Here is the source code for com.lampard.netty4.protocol.udp.ChineseProverbServerHandler.java

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/*
 * 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.lampard.netty4.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();
    }
}