Netty案例

package demo08;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;

/**
 * @author yangxinlei
 * @date 2020/6/28
 */
public class EchoServer {

    public static void main(String[] args) throws Exception {
        int port = 8080;
        if(args != null && args.length > 0){
            try {
                port = Integer.valueOf(args[0]);
            } catch (NumberFormatException e) {
                // 採用默認值
            }
        }
        new EchoServer().bind(port);
    }

    public void bind(int port) throws Exception{
        //第一步：
        // 配置服務端的NIO線程組
        // 主線程組, 用於接受客戶端的連接，但是不做任何具體業務處理，像老闆一樣，負責接待客戶，不具體服務客戶
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        // 工作線程組, 老闆線程組會把任務丟給他，讓手下線程組去做任務，服務客戶
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            // 類ServerBootstrap用於配置Server相關參數，並啓動Server
            ServerBootstrap b = new ServerBootstrap();

            //鏈式調用
            //配置parentGroup和childGroup
            b.group(bossGroup, workerGroup)
                    //配置Server通道
                    .channel(NioServerSocketChannel.class)
                    //配置通道的ChannelPipeline
                    .childHandler(new ChildChannelHandler());

            // 綁定端口，並啓動server，同時設置啓動方式爲同步
            ChannelFuture f = b.bind(port).sync();

            System.out.println(EchoServer.class.getName() +
                    " 啓動成功，在地址[" + f.channel().localAddress() +"]上等待客戶請求......");

            // 等待服務端監聽端口關閉
            f.channel().closeFuture().sync();
        } finally {
            // 優雅退出，釋放線程池資源
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    private class ChildChannelHandler extends ChannelInitializer<SocketChannel> {
        @Override
        protected void initChannel(SocketChannel channel) throws Exception {
            channel.pipeline().addLast(new EchoServerHandler());
        }
    }

}

package demo08;


import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;
/**
 * @author yangxinlei
 * @date 2020/6/28
 */
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf in = (ByteBuf) msg;
        System.out.println("服務器接收到消息：" + in.toString(CharsetUtil.UTF_8));
        ctx.write(in);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx)
            throws Exception {
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
                .addListener(ChannelFutureListener.CLOSE);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx,
                                Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}

package demo08;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.util.CharsetUtil;
/**
 * @author yangxinlei
 * @date 2020/6/28
 */
public class EchoClientHandler extends SimpleChannelInboundHandler<ByteBuf> {
    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(Unpooled.copiedBuffer("測試一下對不對！", CharsetUtil.UTF_8));
    }

    @Override
    public void channelRead0(ChannelHandlerContext ctx, ByteBuf in) {
        System.out.println("客戶端接收到消息： " + in.toString(CharsetUtil.UTF_8));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}

package demo08;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;


/**
 * @author yangxinlei
 * @date 2020/6/28
 */
public class EchoClient {

    public static void main(String[] args) throws Exception {
        int port = 8080;
        if (args != null && args.length > 0) {
            try {
                port = Integer.valueOf(args[0]);
            } catch (NumberFormatException e) {
            }
        }
        new EchoClient().connect(port, "127.0.0.1");
    }

    public void connect(int port, String host) throws Exception {
        // 工作線程組, 老闆線程組會把任務丟給他，讓手下線程組去做任務，服務客戶
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group).channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY, true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new EchoClientHandler());
                        }
                    });

            // 發起異步連接操作
            ChannelFuture f = b.connect(host, port).sync();

            // 等待客戶端鏈路關閉
            f.channel().closeFuture().sync();
        } finally {
            // 優雅退出，釋放線程池資源
            group.shutdownGracefully();
        }
    }
}