Class HandlerPublisher<T>
- java.lang.Object
-
- io.netty.channel.ChannelHandlerAdapter
-
- io.netty.channel.ChannelInboundHandlerAdapter
-
- io.netty.channel.ChannelDuplexHandler
-
- software.amazon.awssdk.http.nio.netty.internal.nrs.HandlerPublisher<T>
-
- All Implemented Interfaces:
io.netty.channel.ChannelHandler
,io.netty.channel.ChannelInboundHandler
,io.netty.channel.ChannelOutboundHandler
,org.reactivestreams.Publisher<T>
public class HandlerPublisher<T> extends io.netty.channel.ChannelDuplexHandler implements org.reactivestreams.Publisher<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. This class contains source imported from https://github.com/playframework/netty-reactive-streams, licensed under the Apache License 2.0, available at the time of the fork (1/31/2020) here: https://github.com/playframework/netty-reactive-streams/blob/master/LICENSE.txt
-
-
Constructor Summary
Constructors Constructor 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 Description protected boolean
acceptInboundMessage(Object msg)
Returnstrue
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
channelReadComplete(io.netty.channel.ChannelHandlerContext ctx)
void
channelRegistered(io.netty.channel.ChannelHandlerContext ctx)
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(org.reactivestreams.Subscriber<? super T> subscriber)
-
Methods inherited from class io.netty.channel.ChannelDuplexHandler
bind, close, connect, deregister, disconnect, flush, read, write
-
-
-
-
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
-
acceptInboundMessage
protected boolean acceptInboundMessage(Object msg) throws Exception
Returnstrue
if the given message should be handled. Iffalse
it will be passed to the nextChannelInboundHandler
in theChannelPipeline
.- Parameters:
msg
- The message to check.- Returns:
- True if the message should be accepted.
- Throws:
Exception
-
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.
-
subscribe
public void subscribe(org.reactivestreams.Subscriber<? super T> subscriber)
- Specified by:
subscribe
in interfaceorg.reactivestreams.Publisher<T>
-
handlerAdded
public void handlerAdded(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
handlerAdded
in interfaceio.netty.channel.ChannelHandler
- Overrides:
handlerAdded
in classio.netty.channel.ChannelHandlerAdapter
- Throws:
Exception
-
channelRegistered
public void channelRegistered(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
channelRegistered
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
channelRegistered
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
channelActive
public void channelActive(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
channelActive
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
channelActive
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
channelRead
public void channelRead(io.netty.channel.ChannelHandlerContext ctx, Object message) throws Exception
- Specified by:
channelRead
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
channelRead
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
channelReadComplete
public void channelReadComplete(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
channelReadComplete
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
channelReadComplete
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
channelInactive
public void channelInactive(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
channelInactive
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
channelInactive
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
handlerRemoved
public void handlerRemoved(io.netty.channel.ChannelHandlerContext ctx) throws Exception
- Specified by:
handlerRemoved
in interfaceio.netty.channel.ChannelHandler
- Overrides:
handlerRemoved
in classio.netty.channel.ChannelHandlerAdapter
- Throws:
Exception
-
exceptionCaught
public void exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause) throws Exception
- Specified by:
exceptionCaught
in interfaceio.netty.channel.ChannelHandler
- Specified by:
exceptionCaught
in interfaceio.netty.channel.ChannelInboundHandler
- Overrides:
exceptionCaught
in classio.netty.channel.ChannelInboundHandlerAdapter
- Throws:
Exception
-
-