package com.casic.missiles.socket;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.AdaptiveRecvByteBufAllocator;
import io.netty.channel.ChannelFuture;
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.NioServerSocketChannel;
import lombok.extern.slf4j.Slf4j;

/**
 * @author a203
 */
@Slf4j
public class BootNettyServer {
    public void bind(int port) {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            /**
             * ServerBootstrap 是一个启动NIO服务的辅助启动类
             */
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            /**
             * 设置group，将bossGroup，workerGroup线程组传递到ServerBootstrap
             */
            serverBootstrap = serverBootstrap.group(bossGroup, workerGroup);
            /**
             * ServerSocketChannel是以NIO的selector为基础进行实现的，用来接收新的连接，这里告诉Channel通过NioServerSocketChannel获取新的连接
             */
            serverBootstrap = serverBootstrap.channel(NioServerSocketChannel.class);
            serverBootstrap = serverBootstrap.option(ChannelOption.RCVBUF_ALLOCATOR, new AdaptiveRecvByteBufAllocator(64, 10496, 1048576));
            serverBootstrap = serverBootstrap.childOption(ChannelOption.RCVBUF_ALLOCATOR, new AdaptiveRecvByteBufAllocator(64, 10496, 1048576));
            /**
             * 设置 I/O处理类,主要用于网络I/O事件，记录日志，编码、解码消息
             */
            serverBootstrap = serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>());
            log.info("端口已开启，占用" + port + "端口号....");
            /**
             * 绑定端口，同步等待成功
             */
            ChannelFuture channelFuture = serverBootstrap.bind(port).sync();
            /**
             * 等待服务器监听端口关闭
             */
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            /**
             * 退出，释放线程池资源
             */
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}