package org.springblade.modules.nettyUdpServer.server;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioDatagramChannel;
import io.netty.handler.codec.json.JsonObjectDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.concurrent.DefaultEventExecutorGroup;
import io.netty.util.concurrent.EventExecutorGroup;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springblade.modules.nettyUdpServer.handle.UdpServerHandler;

import java.net.InetAddress;
import java.util.concurrent.Executors;

/**
 * updServer udp服务端
 */
public class UdpServer {
	private static Logger LOG = LoggerFactory.getLogger(UdpServer.class);

	public int port;

	private Channel channel;

	public UdpServer(int port) {
		this.port = port;
		run();
	}


	//给管道抽象出接口，给Channel更多的能力和配置，例如Channel的状态，参数，IO操作
	//使用ChannelPipeline实现自定义IO
	//Channel channel;
	public void run() {
		Thread thread = new Thread(new Runnable() {
			@Override
			public void run() {
				//InetSocketAddress socketAddress = new InetSocketAddress("s16s652780.51mypc.cn", 21403);
				//启动服务
				EventLoopGroup workerGroup = new NioEventLoopGroup();
				//优化使用的线程
				final EventExecutorGroup group = new DefaultEventExecutorGroup(16);

				try {
					Bootstrap b = new Bootstrap();//udp不能使用ServerBootstrap
					b.group(workerGroup).channel(NioDatagramChannel.class)//设置UDP通道
						//设置udp的管道工厂
						.handler(new ChannelInitializer<NioDatagramChannel>() {
							//NioDatagramChannel标志着是UDP格式的
							@Override
							protected void initChannel(NioDatagramChannel ch)
								throws Exception {
								// TODO Auto-generated method stub
								//创建一个执行Handler的容器
								ChannelPipeline pipeline = ch.pipeline();
								pipeline.addLast(new StringDecoder());
								pipeline.addLast(new StringEncoder());
								//执行具体的处理器
								pipeline.addLast(group, "handler", new UdpServerHandler());//消息处理器
							}

						})//初始化处理器
						//true / false 多播模式(UDP适用),可以向多个主机发送消息
						.option(ChannelOption.SO_BROADCAST, true)// 支持广播
						.option(ChannelOption.SO_RCVBUF, 2048 * 1024)// 设置UDP读缓冲区为2M
						.option(ChannelOption.SO_SNDBUF, 1024 * 1024);// 设置UDP写缓冲区为1M

					// 绑定端口，开始接收进来的连接
					ChannelFuture f = b.bind(port).sync();
					//获取channel通道
					//channel=f.channel();
					System.out.println("UDP Server 启动,端口:"+port);
					// 等待服务器 socket 关闭 。
					// 这不会发生，可以优雅地关闭服务器。
					f.channel().closeFuture().sync();
				} catch (InterruptedException e) {
					e.printStackTrace();
				} finally {
					// 优雅退出 释放线程池资源
					group.shutdownGracefully();
					workerGroup.shutdownGracefully();
				}
			}
			});
		thread.start();
	}

}