FlowControlHandler (Netty API Reference (4.1.22.Final))

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelInboundHandlerAdapter
  - - io.netty.channel.ChannelDuplexHandler
    - - io.netty.handler.flow.FlowControlHandler

All Implemented Interfaces:

ChannelHandler ， ChannelInboundHandler ， ChannelOutboundHandler
```
public class FlowControlHandler
extends ChannelDuplexHandler
```
FlowControlHandler确保每read()只向下游发送一条消息。诸如ByteToMessageDecoder或MessageToByteEncoder等类可以自由地为任何给定的输入发出尽可能多的事件。频道的自动阅读配置通常不适用于这些情况。这导致下游ChannelHandler的问题，它们想要在处理一个事件时保留后续事件。这是HttpObjectDecoder常见的问题，通常会触发HttpRequest ，紧接着是LastHttpContent事件。
```
  {@code
 ChannelPipeline pipeline = ...;

 pipeline.addLast(new HttpServerCodec());
 pipeline.addLast(new FlowControlHandler());

 pipeline.addLast(new MyExampleHandler());

 class MyExampleHandler extends ChannelInboundHandlerAdapter { 
```
另请参见：

ChannelConfig.setAutoRead(boolean)

Nested Class Summary
- Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler
  ChannelHandler.Sharable

构造方法摘要

构造方法
Constructor and Description
`FlowControlHandler()`
`FlowControlHandler(boolean releaseMessages)`

方法摘要

所有方法接口方法具体的方法
Modifier and Type	Method and Description
`void`	`channelInactive(ChannelHandlerContext ctx)` 致电`ChannelHandlerContext.fireChannelInactive()`转发到`ChannelPipeline`中的下一个`ChannelInboundHandler` 。
`void`	`channelRead(ChannelHandlerContext ctx, java.lang.Object msg)` 致电`ChannelHandlerContext.fireChannelRead(Object)`转发至`ChannelPipeline`中的下一个`ChannelInboundHandler` 。
`void`	`channelReadComplete(ChannelHandlerContext ctx)` 致电`ChannelHandlerContext.fireChannelReadComplete()`转发到`ChannelPipeline`中的下一个`ChannelInboundHandler` 。
`void`	`handlerAdded(ChannelHandlerContext ctx)` 子类可以忽略这个方法。
`void`	`read(ChannelHandlerContext ctx)` 致电`ChannelHandlerContext.read()`转发至`ChannelPipeline`中的下一个`ChannelOutboundHandler` 。

Methods inherited from class io.netty.channel.ChannelDuplexHandler
bind, close, connect, deregister, disconnect, flush, write

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter
channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter
ensureNotSharable, handlerRemoved, isSharable

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.netty.channel.ChannelHandler
exceptionCaught, handlerRemoved

- 构造方法详细信息
  - FlowControlHandler
```
public FlowControlHandler()
```
  - FlowControlHandler
```
public FlowControlHandler(boolean releaseMessages)
```
- 方法详细信息
  - handlerAdded
```
public void handlerAdded(ChannelHandlerContext ctx)
                  throws java.lang.Exception
```
    从类复制的描述： ChannelHandlerAdapter
    
    子类可以忽略这个方法。
    
    Specified by:
    
    handlerAdded ，界面 ChannelHandler
    
    重写：
    
    handlerAdded在课堂上 ChannelHandlerAdapter
    
    异常
    
    java.lang.Exception
  - channelInactive
```
public void channelInactive(ChannelHandlerContext ctx)
                     throws java.lang.Exception
```
    从类复制的描述： ChannelInboundHandlerAdapter
    
    致电ChannelHandlerContext.fireChannelInactive()转发到ChannelPipeline中的下一个ChannelInboundHandler 。子类可以重写此方法来更改行为。
    
    Specified by:
    
    channelInactive在界面 ChannelInboundHandler
    
    重写：
    
    channelInactive在课堂上 ChannelInboundHandlerAdapter
    
    异常
    
    java.lang.Exception
  - read
```
public void read(ChannelHandlerContext ctx)
          throws java.lang.Exception
```
    从类复制的描述： ChannelDuplexHandler
    
    致电ChannelHandlerContext.read()转发到ChannelPipeline中的下一个ChannelOutboundHandler 。子类可以重写此方法来更改行为。
    
    Specified by:
    
    read在界面 ChannelOutboundHandler
    
    重写：
    
    read在课堂上 ChannelDuplexHandler
    
    异常
    
    java.lang.Exception
  - channelRead
```
public void channelRead(ChannelHandlerContext ctx,
                        java.lang.Object msg)
                 throws java.lang.Exception
```
    从类复制的描述： ChannelInboundHandlerAdapter
    
    致电ChannelHandlerContext.fireChannelRead(Object)转发到ChannelPipeline中的下一个ChannelInboundHandler 。子类可以重写此方法来更改行为。
    
    Specified by:
    
    channelRead在界面 ChannelInboundHandler
    
    重写：
    
    channelRead在课堂上 ChannelInboundHandlerAdapter
    
    异常
    
    java.lang.Exception
  - channelReadComplete
```
public void channelReadComplete(ChannelHandlerContext ctx)
                         throws java.lang.Exception
```
    从类复制的描述： ChannelInboundHandlerAdapter
    
    致电ChannelHandlerContext.fireChannelReadComplete()转发到ChannelPipeline中的下一个ChannelInboundHandler 。子类可以重写此方法来更改行为。
    
    Specified by:
    
    channelReadComplete在界面 ChannelInboundHandler
    
    重写：
    
    channelReadComplete在课堂上 ChannelInboundHandlerAdapter
    
    异常
    
    java.lang.Exception

Class FlowControlHandler

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

构造方法摘要

方法摘要

Methods inherited from class io.netty.channel.ChannelDuplexHandler

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

Methods inherited from class java.lang.Object

Methods inherited from interface io.netty.channel.ChannelHandler

构造方法详细信息

FlowControlHandler

FlowControlHandler

方法详细信息

handlerAdded

channelInactive

read

channelRead

channelReadComplete