org.springframework.http.server.reactive

Class AbstractListenerReadPublisher<T>

java.lang.Object

org.springframework.http.server.reactive.AbstractListenerReadPublisher<T>

Type Parameters:

T - the type of element signaled

All Implemented Interfaces:

Publisher<T>

public abstract class AbstractListenerReadPublisher<T>
extends Object
implements Publisher<T>

Abstract base class for Publisher implementations that bridge between event-listener read APIs and Reactive Streams.

Specifically a base class for reading from the HTTP request body with Servlet 3.1 non-blocking I/O and Undertow XNIO as well as handling incoming WebSocket messages with standard Java WebSocket (JSR-356), Jetty, and Undertow.

Since:

5.0

Author:

Arjen Poutsma, Violeta Georgieva, Rossen Stoyanchev

Field Summary

Fields

Modifier and Type	Field and Description
protected static Log	rsReadLogger Special logger for debugging Reactive Streams signals.

Constructor Summary

Constructors

Constructor and Description
AbstractListenerReadPublisher()
AbstractListenerReadPublisher(String logPrefix) Create an instance with the given log prefix.

Method Summary

Modifier and Type	Method and Description
protected abstract void	checkOnDataAvailable() Check if data is available and either call onDataAvailable() immediately or schedule a notification.
protected abstract void	discardData() Invoked after an I/O read error from the underlying server or after a cancellation signal from the downstream consumer to allow sub-classes to discard any current cached data they might have.
String	getLogPrefix() Return the configured log message prefix.
void	onAllDataRead() Sub-classes can call this method to delegate a contain notification when all data has been read.
void	onDataAvailable() Invoked when reading is possible, either in the same thread after a check via checkOnDataAvailable(), or as a callback from the underlying container.
void	onError(Throwable ex) Sub-classes can call this to delegate container error notifications.
protected abstract T	read() Read once from the input, if possible.
protected abstract void	readingPaused() Invoked when reading is paused due to a lack of demand.
void	subscribe(Subscriber<? super T> subscriber)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

rsReadLogger

protected static Log rsReadLogger

Special logger for debugging Reactive Streams signals.

See Also:

LogDelegateFactory.getHiddenLog(Class), AbstractListenerWriteProcessor.rsWriteLogger, AbstractListenerWriteFlushProcessor.rsWriteFlushLogger, WriteResultPublisher.rsWriteResultLogger

Constructor Detail

AbstractListenerReadPublisher

public AbstractListenerReadPublisher()

AbstractListenerReadPublisher

public AbstractListenerReadPublisher(String logPrefix)

Create an instance with the given log prefix.

Since:

5.1

Method Detail

getLogPrefix

public String getLogPrefix()

Return the configured log message prefix.

Since:

5.1

subscribe

public void subscribe(Subscriber<? super T> subscriber)

Specified by:

subscribe in interface Publisher<T>

onDataAvailable

public final void onDataAvailable()

Invoked when reading is possible, either in the same thread after a check via checkOnDataAvailable(), or as a callback from the underlying container.

onAllDataRead

public void onAllDataRead()

Sub-classes can call this method to delegate a contain notification when all data has been read.

onError

public final void onError(Throwable ex)

Sub-classes can call this to delegate container error notifications.

checkOnDataAvailable

protected abstract void checkOnDataAvailable()

Check if data is available and either call onDataAvailable() immediately or schedule a notification.

read

@Nullable
protected abstract T read()
                             throws IOException

Read once from the input, if possible.

Returns:

the item that was read; or null

Throws:

IOException

readingPaused

protected abstract void readingPaused()

Invoked when reading is paused due to a lack of demand.

Note: This method is guaranteed not to compete with checkOnDataAvailable() so it can be used to safely suspend reading, if the underlying API supports it, i.e. without competing with an implicit call to resume via checkOnDataAvailable().

Since:

5.0.2

discardData

protected abstract void discardData()

Invoked after an I/O read error from the underlying server or after a cancellation signal from the downstream consumer to allow sub-classes to discard any current cached data they might have.

Since:

5.0.11