MessageAggregator (Netty 4.1.109.Final API文档

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelInboundHandlerAdapter
  - - io.netty.handler.codec.MessageToMessageDecoder<I>
    - - io.netty.handler.codec.MessageAggregator<I,S,C,O>

类型参数:

I - the type that covers both start message and content message

S - the type of the start message

C - the type of the content message (must be a subtype of ByteBufHolder)

O - the type of the aggregated message (must be a subtype of S and ByteBufHolder)

所有已实现的接口:

ChannelHandler, ChannelInboundHandler

直接已知子类:

AbstractMemcacheObjectAggregator, HttpObjectAggregator, RedisBulkStringAggregator, StompSubframeAggregator, WebSocketFrameAggregator
```
public abstract class MessageAggregator<I,S,C extends ByteBufHolder,O extends ByteBufHolder>
extends MessageToMessageDecoder<I>
```
An abstract ChannelHandler that aggregates a series of message objects into a single aggregated message.
'A series of messages' is composed of the following:
- a single start message which optionally contains the first part of the content, and
- 1 or more content messages.
The content of the aggregated message will be the merged content of the start message and its following content messages. If this aggregator encounters a content message where isLastContentMessage(ByteBufHolder) return true for, the aggregator will finish the aggregation and produce the aggregated message and expect another start message.

嵌套类概要
- 从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler
  ChannelHandler.Sharable

构造器概要

构造器
限定符	构造器和说明
`protected`	`MessageAggregator(int maxContentLength)` Creates a new instance.
`protected`	`MessageAggregator(int maxContentLength, java.lang.Class<? extends I> inboundMessageType)`

方法概要

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
限定符和类型	方法和说明
`boolean`	`acceptInboundMessage(java.lang.Object msg)` Returns `true` if the given message should be handled.
`protected void`	`aggregate(O aggregated, C content)` Transfers the information provided by the specified content message to the specified aggregated message.
`protected abstract O`	`beginAggregation(S start, ByteBuf content)` Creates a new aggregated message from the specified start message and the specified content.
`void`	`channelInactive(ChannelHandlerContext ctx)` Calls `ChannelHandlerContext.fireChannelInactive()` to forward to the next `ChannelInboundHandler` in the `ChannelPipeline`.
`void`	`channelReadComplete(ChannelHandlerContext ctx)` Calls `ChannelHandlerContext.fireChannelReadComplete()` to forward to the next `ChannelInboundHandler` in the `ChannelPipeline`.
`protected abstract boolean`	`closeAfterContinueResponse(java.lang.Object msg)` Determine if the channel should be closed after the result of `newContinueResponse(Object, int, ChannelPipeline)` is written.
`protected ChannelHandlerContext`	`ctx()`
`protected void`	`decode(ChannelHandlerContext ctx, I msg, java.util.List<java.lang.Object> out)` Decode from one message to an other.
`protected void`	`finishAggregation(O aggregated)` Invoked when the specified `aggregated` message is about to be passed to the next handler in the pipeline.
`protected void`	`handleOversizedMessage(ChannelHandlerContext ctx, S oversized)` Invoked when an incoming request exceeds the maximum content length.
`void`	`handlerAdded(ChannelHandlerContext ctx)` Do nothing by default, sub-classes may override this method.
`void`	`handlerRemoved(ChannelHandlerContext ctx)` Do nothing by default, sub-classes may override this method.
`protected abstract boolean`	`ignoreContentAfterContinueResponse(java.lang.Object msg)` Determine if all objects for the current request/response should be ignored or not.
`protected abstract boolean`	`isAggregated(I msg)` Returns `true` if and only if the specified message is already aggregated.
`protected abstract boolean`	`isContentLengthInvalid(S start, int maxContentLength)` Determine if the message `start`'s content length is known, and if it greater than `maxContentLength`.
`protected abstract boolean`	`isContentMessage(I msg)` Returns `true` if and only if the specified message is a content message.
`boolean`	`isHandlingOversizedMessage()` 已过时。 This method will be removed in future releases.
`protected abstract boolean`	`isLastContentMessage(C msg)` Returns `true` if and only if the specified message is the last content message.
`protected abstract boolean`	`isStartMessage(I msg)` Returns `true` if and only if the specified message is a start message.
`int`	`maxContentLength()` Returns the maximum allowed length of the aggregated message in bytes.
`int`	`maxCumulationBufferComponents()` Returns the maximum number of components in the cumulation buffer.
`protected abstract java.lang.Object`	`newContinueResponse(S start, int maxContentLength, ChannelPipeline pipeline)` Returns the 'continue response' for the specified start message if necessary.
`void`	`setMaxCumulationBufferComponents(int maxCumulationBufferComponents)` Sets the maximum number of components in the cumulation buffer.

从类继承的方法 io.netty.handler.codec.MessageToMessageDecoder
channelRead

从类继承的方法 io.netty.channel.ChannelInboundHandlerAdapter
channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

从类继承的方法 io.netty.channel.ChannelHandlerAdapter
ensureNotSharable, isSharable

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - MessageAggregator
```
protected MessageAggregator(int maxContentLength)
```
    Creates a new instance.
    
    参数:
    
    maxContentLength - the maximum length of the aggregated content. If the length of the aggregated content exceeds this value, handleOversizedMessage(ChannelHandlerContext, Object) will be called.
  - MessageAggregator
```
protected MessageAggregator(int maxContentLength,
                            java.lang.Class<? extends I> inboundMessageType)
```
- 方法详细资料
  - acceptInboundMessage
```
public boolean acceptInboundMessage(java.lang.Object msg)
                             throws java.lang.Exception
```
    从类复制的说明: MessageToMessageDecoder
    
    Returns true if the given message should be handled. If false it will be passed to the next ChannelInboundHandler in the ChannelPipeline.
    
    覆盖:
    
    acceptInboundMessage 在类中 MessageToMessageDecoder<I>
    
    抛出:
    
    java.lang.Exception
  - isStartMessage
```
protected abstract boolean isStartMessage(I msg)
                                   throws java.lang.Exception
```
    Returns true if and only if the specified message is a start message. Typically, this method is implemented as a single return statement with instanceof:
```
 return msg instanceof MyStartMessage;
 
```
    抛出:
    
    java.lang.Exception
  - isContentMessage
```
protected abstract boolean isContentMessage(I msg)
                                     throws java.lang.Exception
```
    Returns true if and only if the specified message is a content message. Typically, this method is implemented as a single return statement with instanceof:
```
 return msg instanceof MyContentMessage;
 
```
    抛出:
    
    java.lang.Exception
  - isLastContentMessage
```
protected abstract boolean isLastContentMessage(C msg)
                                         throws java.lang.Exception
```
    Returns true if and only if the specified message is the last content message. Typically, this method is implemented as a single return statement with instanceof:
```
 return msg instanceof MyLastContentMessage;
 
```
    or with instanceof and boolean field check:
```
 return msg instanceof MyContentMessage && msg.isLastFragment();
 
```
    抛出:
    
    java.lang.Exception
  - isAggregated
```
protected abstract boolean isAggregated(I msg)
                                 throws java.lang.Exception
```
    Returns true if and only if the specified message is already aggregated. If this method returns true, this handler will simply forward the message to the next handler as-is.
    
    抛出:
    
    java.lang.Exception
  - maxContentLength
```
public final int maxContentLength()
```
    Returns the maximum allowed length of the aggregated message in bytes.
  - maxCumulationBufferComponents
```
public final int maxCumulationBufferComponents()
```
    Returns the maximum number of components in the cumulation buffer. If the number of the components in the cumulation buffer exceeds this value, the components of the cumulation buffer are consolidated into a single component, involving memory copies. The default value of this property is .
  - setMaxCumulationBufferComponents
```
public final void setMaxCumulationBufferComponents(int maxCumulationBufferComponents)
```
    Sets the maximum number of components in the cumulation buffer. If the number of the components in the cumulation buffer exceeds this value, the components of the cumulation buffer are consolidated into a single component, involving memory copies. The default value of this property is and its minimum allowed value is 2.
  - isHandlingOversizedMessage
```
@Deprecated
public final boolean isHandlingOversizedMessage()
```
    已过时。 This method will be removed in future releases.
  - ctx
```
protected final ChannelHandlerContext ctx()
```
  - decode
```
protected void decode(ChannelHandlerContext ctx,
                      I msg,
                      java.util.List<java.lang.Object> out)
               throws java.lang.Exception
```
    从类复制的说明: MessageToMessageDecoder
    
    Decode from one message to an other. This method will be called for each written message that can be handled by this decoder.
    
    指定者:
    
    decode 在类中 MessageToMessageDecoder<I>
    
    参数:
    
    ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to
    
    msg - the message to decode to an other one
    
    out - the List to which decoded messages should be added
    
    抛出:
    
    java.lang.Exception - is thrown if an error occurs
  - isContentLengthInvalid
```
protected abstract boolean isContentLengthInvalid(S start,
                                                  int maxContentLength)
                                           throws java.lang.Exception
```
    Determine if the message start's content length is known, and if it greater than maxContentLength.
    
    参数:
    
    start - The message which may indicate the content length.
    
    maxContentLength - The maximum allowed content length.
    
    返回:
    
    true if the message start's content length is known, and if it greater than maxContentLength. false otherwise.
    
    抛出:
    
    java.lang.Exception
  - newContinueResponse
```
protected abstract java.lang.Object newContinueResponse(S start,
                                                        int maxContentLength,
                                                        ChannelPipeline pipeline)
                                                 throws java.lang.Exception
```
    Returns the 'continue response' for the specified start message if necessary. For example, this method is useful to handle an HTTP 100-continue header.
    
    返回:
    
    the 'continue response', or null if there's no message to send
    
    抛出:
    
    java.lang.Exception
  - closeAfterContinueResponse
```
protected abstract boolean closeAfterContinueResponse(java.lang.Object msg)
                                               throws java.lang.Exception
```
    Determine if the channel should be closed after the result of newContinueResponse(Object, int, ChannelPipeline) is written.
    
    参数:
    
    msg - The return value from newContinueResponse(Object, int, ChannelPipeline).
    
    返回:
    
    true if the channel should be closed after the result of newContinueResponse(Object, int, ChannelPipeline) is written. false otherwise.
    
    抛出:
    
    java.lang.Exception
  - ignoreContentAfterContinueResponse
```
protected abstract boolean ignoreContentAfterContinueResponse(java.lang.Object msg)
                                                       throws java.lang.Exception
```
    Determine if all objects for the current request/response should be ignored or not. Messages will stop being ignored the next time isContentMessage(Object) returns true.
    
    参数:
    
    msg - The return value from newContinueResponse(Object, int, ChannelPipeline).
    
    返回:
    
    true if all objects for the current request/response should be ignored or not. false otherwise.
    
    抛出:
    
    java.lang.Exception
  - beginAggregation
```
protected abstract O beginAggregation(S start,
                                      ByteBuf content)
                               throws java.lang.Exception
```
    Creates a new aggregated message from the specified start message and the specified content. If the start message implements ByteBufHolder, its content is appended to the specified content. This aggregator will continue to append the received content to the specified content.
    
    抛出:
    
    java.lang.Exception
  - aggregate
```
protected void aggregate(O aggregated,
                         C content)
                  throws java.lang.Exception
```
    Transfers the information provided by the specified content message to the specified aggregated message. Note that the content of the specified content message has been appended to the content of the specified aggregated message already, so that you don't need to. Use this method to transfer the additional information that the content message provides to aggregated.
    
    抛出:
    
    java.lang.Exception
  - finishAggregation
```
protected void finishAggregation(O aggregated)
                          throws java.lang.Exception
```
    Invoked when the specified aggregated message is about to be passed to the next handler in the pipeline.
    
    抛出:
    
    java.lang.Exception
  - handleOversizedMessage
```
protected void handleOversizedMessage(ChannelHandlerContext ctx,
                                      S oversized)
                               throws java.lang.Exception
```
    Invoked when an incoming request exceeds the maximum content length. The default behvaior is to trigger an exceptionCaught() event with a TooLongFrameException.
    
    参数:
    
    ctx - the ChannelHandlerContext
    
    oversized - the accumulated message up to this point, whose type is S or O
    
    抛出:
    
    java.lang.Exception
  - channelReadComplete
```
public void channelReadComplete(ChannelHandlerContext ctx)
                         throws java.lang.Exception
```
    从类复制的说明: ChannelInboundHandlerAdapter
    
    Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.
    
    指定者:
    
    channelReadComplete 在接口中 ChannelInboundHandler
    
    覆盖:
    
    channelReadComplete 在类中 ChannelInboundHandlerAdapter
    
    抛出:
    
    java.lang.Exception
  - channelInactive
```
public void channelInactive(ChannelHandlerContext ctx)
                     throws java.lang.Exception
```
    从类复制的说明: ChannelInboundHandlerAdapter
    
    Calls ChannelHandlerContext.fireChannelInactive() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.
    
    指定者:
    
    channelInactive 在接口中 ChannelInboundHandler
    
    覆盖:
    
    channelInactive 在类中 ChannelInboundHandlerAdapter
    
    抛出:
    
    java.lang.Exception
  - handlerAdded
```
public void handlerAdded(ChannelHandlerContext ctx)
                  throws java.lang.Exception
```
    从类复制的说明: ChannelHandlerAdapter
    
    Do nothing by default, sub-classes may override this method.
    
    指定者:
    
    handlerAdded 在接口中 ChannelHandler
    
    覆盖:
    
    handlerAdded 在类中 ChannelHandlerAdapter
    
    抛出:
    
    java.lang.Exception
  - handlerRemoved
```
public void handlerRemoved(ChannelHandlerContext ctx)
                    throws java.lang.Exception
```
    从类复制的说明: ChannelHandlerAdapter
    
    Do nothing by default, sub-classes may override this method.
    
    指定者:
    
    handlerRemoved 在接口中 ChannelHandler
    
    覆盖:
    
    handlerRemoved 在类中 ChannelHandlerAdapter
    
    抛出:
    
    java.lang.Exception

类 MessageAggregator<I,S,C extends ByteBufHolder,O extends ByteBufHolder>

嵌套类概要

从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler

构造器概要

方法概要

从类继承的方法 io.netty.handler.codec.MessageToMessageDecoder

从类继承的方法 io.netty.channel.ChannelInboundHandlerAdapter

从类继承的方法 io.netty.channel.ChannelHandlerAdapter

从类继承的方法 java.lang.Object

构造器详细资料

MessageAggregator

MessageAggregator

方法详细资料

acceptInboundMessage

isStartMessage

isContentMessage

isLastContentMessage

isAggregated

maxContentLength

maxCumulationBufferComponents

setMaxCumulationBufferComponents

isHandlingOversizedMessage

ctx

decode

isContentLengthInvalid

newContinueResponse

closeAfterContinueResponse

ignoreContentAfterContinueResponse

beginAggregation

aggregate

finishAggregation

handleOversizedMessage

channelReadComplete

channelInactive

handlerAdded

handlerRemoved