Netty非阻塞模型

短命女 2022-09-04 11:49 175阅读 0赞

Netty的很多操作是非阻塞的，像bind、connect、write等，这些操作调用后紧接着返回一个ChannelFuture，它是一个异步执行结果，通过ChannelFuture可以获取执行状态及添加监听器，当执行完成会通知监听器。

package com.tech.netty.netty;
    
    
    import io.netty.bootstrap.ServerBootstrap;
    import io.netty.channel.ChannelFuture;
    import io.netty.channel.ChannelFutureListener;
    import io.netty.channel.ChannelInitializer;
    import io.netty.channel.ChannelOption;
    import io.netty.channel.nio.NioEventLoopGroup;
    import io.netty.channel.socket.SocketChannel;
    import io.netty.channel.socket.nio.NioServerSocketChannel;
    
    import java.util.ArrayList;
    import java.util.HashSet;
    import java.util.List;
    import java.util.Set;
    
    /**
     * @author lw
     * @since 2021/8/11
     **/
    public class NettyServer {
    
        public static final Set<SocketChannel> customerChannelList=new HashSet<>();
    
        public static void main(String[] args) throws InterruptedException {
    
            //1 创建两个线程组bossGroup workerGroup
            //2 bossGroup处理客户端连接请求 workerGroup处理客户端数据读写请求
            //3 他们都是事件循环组 默认含有CPU核数*2个事件循环NioEventLoop
            NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
            NioEventLoopGroup workerGroup = new NioEventLoopGroup(2);
            try {
                //创建服务器端启动对象，进行参数配置
                ServerBootstrap serverBootstrap = new ServerBootstrap();
    
                serverBootstrap.group(bossGroup, workerGroup)  //设置两个线程组
                        .channel(NioServerSocketChannel.class)  //设置服务器端通道为NioServerSocketChannel
                        .option(ChannelOption.SO_BACKLOG, 128) //设置连接队列允许的连接个数
                        .childOption(ChannelOption.SO_KEEPALIVE, true) //设置连接连接状态为活动连接
                        .childHandler(new ChannelInitializer<SocketChannel>() { //给workerGroup NioEventLoop通过管道添加处理器
                            @Override
                            protected void initChannel(SocketChannel socketChannel) throws Exception {
                                socketChannel.pipeline().addLast(new NettyServerHandler());
                                customerChannelList.add(socketChannel);
                                customerChannelList.forEach(c->{
                                    System.out.println("|"+c.hashCode()+"|");
                                });
                            }
                        });
                System.out.println("...服务器 is ready...");
                //启动服务器并绑定一个端口
                ChannelFuture channelFuture = serverBootstrap.bind(6668).sync();
                channelFuture.addListener(new ChannelFutureListener() {
                    @Override
                    public void operationComplete(ChannelFuture channelFuture) throws Exception {
                        if(channelFuture.isSuccess()){
                            System.out.println("服务启动成功");
                        }else{
                            System.out.println("服务启动失败");
                        }
                    }
                });
                //对通道的关闭事件进行监听
                channelFuture.channel().closeFuture().sync();
            } finally {
                bossGroup.shutdownGracefully();
                workerGroup.shutdownGracefully();
            }
        }
    }