HandlerPublisher (micronaut 3.9.3 API)

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelInboundHandlerAdapter
  - - io.netty.channel.ChannelDuplexHandler
    - - io.micronaut.http.netty.reactive.HandlerPublisher<T>

Type Parameters:

T - The publisher type

All Implemented Interfaces:

HotObservable<T>, io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler, Publisher<T>
```
@Internal
public class HandlerPublisher<T>
extends io.netty.channel.ChannelDuplexHandler
implements HotObservable<T>
```
Publisher for a Netty Handler.
This publisher supports only one subscriber.
All interactions with the subscriber are done from the handlers executor, hence, they provide the same happens before semantics that Netty provides.
The handler publishes all messages that match the type as specified by the passed in class. Any non matching messages are forwarded to the next handler.
The publisher will signal complete if it receives a channel inactive event.
The publisher will release any messages that it drops (for example, messages that are buffered when the subscriber cancels), but other than that, it does not release any messages. It is up to the subscriber to release messages.
If the subscriber cancels, the publisher will send a close event up the channel pipeline.
All errors will short circuit the buffer, and cause publisher to immediately call the subscribers onError method, dropping the buffer.
The publisher can be subscribed to or placed in a handler chain in any order.

Since:

1.0

Author:

Graeme Rocher

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

Constructor Summary

Constructors
Constructor and Description
`HandlerPublisher(io.netty.util.concurrent.EventExecutor executor, Class<? extends T> subscriberMessageType)` Create a handler publisher.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected boolean`	`acceptInboundMessage(Object msg)` Returns `true` if the given message should be handled.
`protected void`	`cancelled()` Override to handle when a subscriber cancels the subscription.
`void`	`channelActive(io.netty.channel.ChannelHandlerContext ctx)`
`void`	`channelInactive(io.netty.channel.ChannelHandlerContext ctx)`
`void`	`channelRead(io.netty.channel.ChannelHandlerContext ctx, Object message)`
`void`	`channelRegistered(io.netty.channel.ChannelHandlerContext ctx)`
`void`	`closeIfNoSubscriber()` Releases buffered data if there is no subscriber.
`void`	`exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause)`
`void`	`handlerAdded(io.netty.channel.ChannelHandlerContext ctx)`
`void`	`handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)`
`protected void`	`requestDemand()` Override to intercept when demand is requested.
`void`	`subscribe(Subscriber<? super T> subscriber)`

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

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter
channelReadComplete, channelUnregistered, channelWritabilityChanged, userEventTriggered

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

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

- Constructor Detail
  - HandlerPublisher
```
public HandlerPublisher(io.netty.util.concurrent.EventExecutor executor,
                        Class<? extends T> subscriberMessageType)
```
    Create a handler publisher.
    The supplied executor must be the same event loop as the event loop that this handler is eventually registered with, if not, an exception will be thrown when the handler is registered.
    
    Parameters:
    
    executor - The executor to execute asynchronous events from the subscriber on.
    
    subscriberMessageType - The type of message this publisher accepts.
- Method Detail
  - subscribe
```
public void subscribe(Subscriber<? super T> subscriber)
```
    Specified by:
    
    subscribe in interface Publisher<T>
  - acceptInboundMessage
```
protected boolean acceptInboundMessage(Object msg)
```
    Returns true if the given message should be handled. If false it will be passed to the next ChannelInboundHandler in the ChannelPipeline.
    
    Parameters:
    
    msg - The message to check.
    
    Returns:
    
    True if the message should be accepted.
  - cancelled
```
protected void cancelled()
```
    Override to handle when a subscriber cancels the subscription.
    By default, this method will simply close the channel.
  - requestDemand
```
protected void requestDemand()
```
    Override to intercept when demand is requested.
    By default, a channel read is invoked.
  - handlerAdded
```
public void handlerAdded(io.netty.channel.ChannelHandlerContext ctx)
```
    Specified by:
    
    handlerAdded in interface io.netty.channel.ChannelHandler
    
    Overrides:
    
    handlerAdded in class io.netty.channel.ChannelHandlerAdapter
  - channelRegistered
```
public void channelRegistered(io.netty.channel.ChannelHandlerContext ctx)
```
    Specified by:
    
    channelRegistered in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    channelRegistered in class io.netty.channel.ChannelInboundHandlerAdapter
  - channelActive
```
public void channelActive(io.netty.channel.ChannelHandlerContext ctx)
```
    Specified by:
    
    channelActive in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    channelActive in class io.netty.channel.ChannelInboundHandlerAdapter
  - channelRead
```
public void channelRead(io.netty.channel.ChannelHandlerContext ctx,
                        Object message)
```
    Specified by:
    
    channelRead in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    channelRead in class io.netty.channel.ChannelInboundHandlerAdapter
  - channelInactive
```
public void channelInactive(io.netty.channel.ChannelHandlerContext ctx)
```
    Specified by:
    
    channelInactive in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    channelInactive in class io.netty.channel.ChannelInboundHandlerAdapter
  - handlerRemoved
```
public void handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)
```
    Specified by:
    
    handlerRemoved in interface io.netty.channel.ChannelHandler
    
    Overrides:
    
    handlerRemoved in class io.netty.channel.ChannelHandlerAdapter
  - exceptionCaught
```
public void exceptionCaught(io.netty.channel.ChannelHandlerContext ctx,
                            Throwable cause)
```
    Specified by:
    
    exceptionCaught in interface io.netty.channel.ChannelHandler
    
    Specified by:
    
    exceptionCaught in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    exceptionCaught in class io.netty.channel.ChannelInboundHandlerAdapter
  - closeIfNoSubscriber
```
public void closeIfNoSubscriber()
```
    Description copied from interface: HotObservable
    
    Releases buffered data if there is no subscriber.
    
    Specified by:
    
    closeIfNoSubscriber in interface HotObservable<T>

Class HandlerPublisher<T>

Nested Class Summary

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

Constructor Summary

Method Summary

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

Constructor Detail

HandlerPublisher

Method Detail

subscribe

acceptInboundMessage

cancelled

requestDemand

handlerAdded

channelRegistered

channelActive

channelRead

channelInactive

handlerRemoved

exceptionCaught

closeIfNoSubscriber