package cn.flightfeather.supervision.infrastructure.service;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

//这个注解表示可以多线程操作
@ChannelHandler.Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf in = (ByteBuf) msg;
        System.out.println("Server received: " + in.toString(CharsetUtil.UTF_8));
        ctx.write(in);//将接收到的消息写给发送者，而不冲刷出站消息，
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER) //flush掉所有写回的数据
                .addListener(ChannelFutureListener.CLOSE); //当flush完成后关闭channel,将未决消息冲刷到远程节点，并且关闭该Channel
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();//捕捉异常信息
        ctx.close();//出现异常时关闭channel
    }
}