Netty開發UDP協議

UdpServer

package org.zln.netty.five.part07;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioDatagramChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Created by sherry on 16/11/7.
 */
public class UdpServer {

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(UdpServer.class);

    public void run(int port){
        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(eventLoopGroup)
                    .channel(NioDatagramChannel.class)
                    .option(ChannelOption.SO_BROADCAST,true)
                    .handler(new UdpServerHandler());
            bootstrap.bind(port).sync().channel().closeFuture().await();
        } catch (InterruptedException e) {
            logger.error(e.getMessage(),e);
        }finally {
            eventLoopGroup.shutdownGracefully();
        }
    }
}

UdpServerHandler

package org.zln.netty.five.part07;

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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.ThreadLocalRandom;

/**
 * Created by sherry on 16/11/7.
 */
public class UdpServerHandler extends SimpleChannelInboundHandler<DatagramPacket> {

    private static final String[] DICT = {
            "只要功夫深,鐵杵磨成針"
            , "舊時王謝堂前燕,飛入尋常百姓家"
            , "洛陽親友如相問,一片冰心在玉壺"
            , "一寸光陰一寸金,寸金難買寸光陰"
            , "老驥伏櫪,志在千里.烈士暮年,壯心不已!"
    };

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(UdpServerHandler.class);

    @Override
    protected void messageReceived(ChannelHandlerContext ctx, DatagramPacket msg) throws Exception {
        String req = msg.content().toString(CharsetUtil.UTF_8);
        logger.debug("收到的請求:" + req);
        if ("諺語字典查詢?".equals(req)) {
            ctx.writeAndFlush(new DatagramPacket(Unpooled.copiedBuffer("諺語查詢結果:" + nextQueue(), CharsetUtil.UTF_8), msg.sender()));
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
        logger.error(cause.getMessage(),cause);
    }

    private String nextQueue() {
        //ThreadLocalRandom 線程安全隨機類
        int quoteId = ThreadLocalRandom.current().nextInt(DICT.length);
        return DICT[quoteId];
    }


}

UdpClient

package org.zln.netty.five.part07;

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.DatagramPacket;
import io.netty.channel.socket.nio.NioDatagramChannel;
import io.netty.util.CharsetUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.InetSocketAddress;

/**
 * Created by sherry on 16/11/7.
 */
public class UdpClient {

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(UdpClient.class);

    public void run(int port) {
        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(eventLoopGroup)
                    .channel(NioDatagramChannel.class)
                    .option(ChannelOption.SO_BROADCAST, true)
                    .handler(new UdpClientHandler());


            Channel channel = bootstrap.bind(0).sync().channel();
            //向網段內的所有機器廣播
            channel.writeAndFlush(new DatagramPacket(Unpooled.copiedBuffer("諺語字典查詢?", CharsetUtil.UTF_8), new InetSocketAddress("255.255.255.255", port))).sync();
            if (!channel.closeFuture().await(15000)) {
                logger.debug("查詢超時");
            }



        } catch (InterruptedException e) {
            logger.error(e.getMessage(), e);
        } finally {
            eventLoopGroup.shutdownGracefully();
        }
    }
}

UdpClientHandler

package org.zln.netty.five.part07;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.DatagramPacket;
import io.netty.util.CharsetUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Created by sherry on 16/11/7.
 */
public class UdpClientHandler extends SimpleChannelInboundHandler<DatagramPacket> {

    /**
     * 日志
     */
    private Logger logger = LoggerFactory.getLogger(UdpClientHandler.class);

    @Override
    protected void messageReceived(ChannelHandlerContext ctx, DatagramPacket msg) throws Exception {
        String resp = msg.content().toString(CharsetUtil.UTF_8);
        if (resp.startsWith("諺語查詢結果:")){
            logger.debug(resp);
            ctx.close();
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) throws Exception {
        logger.error(e.getMessage(),e);
        ctx.close();
    }
}