Netty中Channel的生命周期（SimpleChannelInboundHandler）

类的说明

public class CustomHandler extends SimpleChannelInboundHandler<HttpObject>{}

1.channelRegistered

channel注册事件

	@Override
	public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel注册了");
		super.channelRegistered(ctx);
	}

2.channelUnregistered

channel取消注册事件

@Override
	public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel移除了");
		super.channelUnregistered(ctx);
	}

3.channelActive

channel是否是活跃

	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 活跃");
		super.channelActive(ctx);
	}

4.channelInactive

channel不活跃

	@Override
	public void channelInactive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 不活跃，断开连接");
		super.channelInactive(ctx);
	}

5.channelReadComplete

channel读取完毕事件

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 读取完毕");
		super.channelReadComplete(ctx);
	}

6.userEventTriggered

channel 用户事件触发

	@Override
	public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
		System.out.println("channel 用户事件触发");
		super.userEventTriggered(ctx, evt);
	}

7.channelWritabilityChanged

channel 可写更改

	@Override
	public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 可写更改");
		super.channelWritabilityChanged(ctx);
	}

8.exceptionCaught

channel 捕获到异常

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
		System.out.println("channel 捕获到异常了，关闭了");
		super.exceptionCaught(ctx, cause);
	}

9.handlerAdded

channel 助手类(拦截器)的添加

	@Override
	public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 助手类添加");
		super.handlerAdded(ctx);
	}

10.handlerRemoved

channel 助手类(拦截器)移除

	@Override
	public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channel 助手类移除");
		super.handlerRemoved(ctx);
	}

11.channelRead0

channel读取数据

@Override
	protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) 
			throws Exception {
		Channel channel = ctx.channel();//获取当前channel
		System.out.println(channel.remoteAddress()); //显示客户端的远程地址
		//定义发送的数据消息
		ByteBuf content = Unpooled.copiedBuffer("Hello cxl",CharsetUtil.UTF_8);
		//构建一个http响应
		FullHttpResponse response =
				new DefaultFullHttpResponse
				(HttpVersion.HTTP_1_1,
						HttpResponseStatus.OK,
						content);
		
		response.headers().set(HttpHeaderNames.CONTENT_TYPE,"text/plain");
		response.headers().set(HttpHeaderNames.CONTENT_LENGTH,content.readableBytes());
		
		//把响应刷到客户端
		ctx.writeAndFlush(response);
		
		
	}

12.执行顺序

当浏览器发送一次请求后