package com.example.demo.client2;

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
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;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

/**
 * DelimiterBasedFrameDecoder半包处理
 * @author 程就人生
 * @date 2019年10月26日
 */
public class DelimiterbaseClient {

    public void connect(int port, String host){
        //客户端Nio线程组
        EventLoopGroup group = new NioEventLoopGroup();
        try{   
            Bootstrap bootstrap = new Bootstrap();
            //线程组设置为非阻塞
            bootstrap.group(group).channel(NioSocketChannel.class)
            .option(ChannelOption.TCP_NODELAY, true)            
            .handler(new ChannelInitializer<SocketChannel>(){
                @Override
                protected void initChannel(SocketChannel ch) throws Exception { 
                	//以特殊符号作为一个包的结束符
                    ByteBuf delimiter = Unpooled.copiedBuffer("$_".getBytes());
                    ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, delimiter));
                    //字符串转对象
                    ch.pipeline().addLast(new StringDecoder());               
                    ch.pipeline().addLast(new DelimiterbaseClientHandler());
             
                }
            });
            
            //建立连接
            ChannelFuture channelFuture = bootstrap.connect(host, port);
            //等待服务端监听端口关闭
            channelFuture.channel().closeFuture().sync();
            
        }catch(Exception e){
            e.printStackTrace();
        }finally{
                        //优雅退出
            group.shutdownGracefully();
        }
    }
    
    public static void main(String[] argo){
        new DelimiterbaseClient().connect(8080, "localhost");
    }
}