Netty实现简单UDP服务器

本文参考《Netty权威指南》

文件列表：

├── ChineseProverbClientHandler.java

├── ChineseProverbClient.java

├── ChineseProverbServerHandler.java

└── ChineseProverbServer.java

package com.xh.netty.test12;

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;

/**

 * Created by root on 1/11/18.

 */

public class ChineseProverbServer {

    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 ChineseProverbServerHandler());

            bootstrap.bind(port).sync().channel().closeFuture().sync();

        } catch (InterruptedException e) {

            e.printStackTrace();

        } finally {

            eventLoopGroup.shutdownGracefully();

        }

    }

    public static void main(String[] args) {

        ChineseProverbServer server = new ChineseProverbServer();

        server.run(8080);

    }

}

package com.xh.netty.test12;

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;

/**

 * Created by root on 1/11/18.

 */

public class ChineseProverbServerHandler extends SimpleChannelInboundHandler<DatagramPacket> {

    private static String[] DIRC = {"哈哈哈哈", "呵呵呵", "嘻嘻嘻"};

    public void messageReceived(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception {

        String req = packet.content().toString(CharsetUtil.UTF_8);

        System.out.println(req);

        if (req.equalsIgnoreCase("QUERY")) {

            ctx.writeAndFlush(new DatagramPacket(Unpooled.copiedBuffer("RESULT:" + nextQuote(), CharsetUtil.UTF_8), packet.sender()));

        }else {

            ctx.writeAndFlush(new DatagramPacket(Unpooled.copiedBuffer("RESULT:" + "ERR", CharsetUtil.UTF_8), packet.sender()));

        }

    }

    private String nextQuote() {

        int quote = ThreadLocalRandom.current().nextInt(DIRC.length);

        return DIRC[quote];

    }

}

package com.xh.netty.test12;

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 java.net.InetSocketAddress;

/**

 * Created by root on 1/11/18.

 */

public class ChineseProverbClient {

    public void run(int port) {

        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();

        Bootstrap bootstrap = new Bootstrap();

        try {

            bootstrap.group(eventLoopGroup).channel(NioDatagramChannel.class)

                    .option(ChannelOption.SO_BROADCAST, true)

                    .handler(new ChineseProverbClientHandler());

            Channel channel = bootstrap.bind(7070).sync().channel();

            channel.writeAndFlush(new DatagramPacket(Unpooled.copiedBuffer("QUERY", CharsetUtil.UTF_8), new InetSocketAddress("255.255.255.255", port))).sync();

            if (!channel.closeFuture().await(15000)) {

                System.out.println("out of time");

            }

        } catch (InterruptedException e) {

            e.printStackTrace();

        } finally {

            eventLoopGroup.shutdownGracefully();

        }　　

    }

    public static void main(String[] args) {

        new ChineseProverbClient().run(8080);

    }

}

package com.xh.netty.test12;

import io.netty.channel.ChannelHandlerContext;

import io.netty.channel.SimpleChannelInboundHandler;

import io.netty.channel.socket.DatagramPacket;

import io.netty.util.CharsetUtil;

/**

 * Created by root on 1/11/18.

 */

public class ChineseProverbClientHandler extends SimpleChannelInboundHandler<DatagramPacket> {

    protected void messageReceived(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception {

        String result = packet.content().toString(CharsetUtil.UTF_8);

        System.out.println("client>>>" + result);

        ctx.close();

    }

}