jsowell-charger-web/jsowell-netty/src/main/java/com/jsowell/netty/client/NettyClientHandler.java

package com.jsowell.netty.client;

import com.jsowell.common.util.DateUtils;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelId;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.ConcurrentHashMap;

/**
 * 客户端处理类
 */
@Slf4j
public class NettyClientHandler extends ChannelInboundHandlerAdapter {

	/**
	 * 计算有多少客户端接入，第一个string为客户端ip
	 */
	private static final ConcurrentHashMap<ChannelId, ChannelHandlerContext> CLIENT_MAP = new ConcurrentHashMap<>();

	@Override
	public void channelActive(ChannelHandlerContext ctx) {
		CLIENT_MAP.put(ctx.channel().id(), ctx);
		log.info("ClientHandler Active");
	}

	/**
	 * @param ctx
	 * @author xiongchuan on 2019/4/28 16:10
	 * @DESCRIPTION: 有服务端端终止连接服务器会触发此函数
	 * @return: void
	 */
	@Override
	public void channelInactive(ChannelHandlerContext ctx) {
		ctx.close();
		log.info("服务端终止了服务");
	}

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) {
		log.info("回写数据:" + msg);
	}


	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
		//cause.printStackTrace();
		log.info("服务端发生异常【" + cause.getMessage() + "】");
		ctx.close();
	}

	/**
	 * @param msg       需要发送的消息内容
	 * @param channelId 连接通道唯一id
	 * @author xiongchuan on 2019/4/28 16:10
	 * @DESCRIPTION: 客户端给服务端发送消息
	 * @return: void
	 */
	public void channelWrite(ChannelId channelId, String msg) {
		ChannelHandlerContext ctx = CLIENT_MAP.get(channelId);
		if (ctx == null) {
			log.info("通道【" + channelId + "】不存在");
			return;
		}
		//将客户端的信息直接返回写入ctx
		ctx.write(msg + " 时间：" + DateUtils.getDateTime());
		//刷新缓存区
		ctx.flush();
	}
}