package com.example.demo.file;

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;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.stream.ChunkedWriteHandler;

/**
 * 文件目录服务器启动类
 * @author
 * @date 2019年11月20日
 */
public class HttpFileServer {
 
	 //文件访问目录，默认项目根目录
     private static final String DEFAULT_URL = "/";
 
     public void run(final int port, final String url) throws Exception {
    	 //创建线程组
         EventLoopGroup bossGroup = new NioEventLoopGroup();         
         EventLoopGroup workerGroup = new NioEventLoopGroup();         
         try {
        	 
             ServerBootstrap b = new ServerBootstrap();             
             b.group(bossGroup, workerGroup)
                     .channel(NioServerSocketChannel.class)
                     .childHandler(new ChannelInitializer<SocketChannel>() {
                         @Override
                         protected void initChannel(SocketChannel ch) throws Exception {
                        	 // 请求消息解码器
                             ch.pipeline().addLast("http-decoder", new HttpRequestDecoder()); 
                             // 目的是将多个消息转换为单一的request或者response对象
                             ch.pipeline().addLast("http-aggregator",new HttpObjectAggregator(65536));
                             // 响应消息解码器
                             ch.pipeline().addLast("http-encoder",new HttpResponseEncoder());
                             // 支持大文件传输
                             ch.pipeline().addLast("http-chunked",new ChunkedWriteHandler());
                             // 业务逻辑處理類
                             ch.pipeline().addLast("fileServerHandler",new HttpFileServerHandler(url));
                         }
                     });
             
             ChannelFuture future = b.bind(port).sync();
             
             System.out.println("HTTP文件目录服务器启动，网址是 : " + "http://127.0.0.1:" + port + url);
             
             future.channel().closeFuture().sync();
             
         } catch (Exception e) {        	 
             e.printStackTrace();             
         } finally {
        	 //优雅退出
             bossGroup.shutdownGracefully();
             workerGroup.shutdownGracefully();
         }
     }
 
     public static void main(String[] args) throws Exception {
    	 //启动文件目录服务器
         new HttpFileServer().run(8080, DEFAULT_URL);
     }
}