org.springframework.http.server.reactive

Class AbstractListenerWriteProcessor<T>

java.lang.Object

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

Direct Known Subclasses:

AbstractListenerWebSocketSession.WebSocketSendProcessor, ServletServerHttpResponse.ResponseBodyProcessor, UndertowServerHttpResponse.ResponseBodyProcessor

public abstract class AbstractListenerWriteProcessor<T>
extends java.lang.Object

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

Specifically a base class for writing to the HTTP response body with Servlet 3.1 non-blocking I/O and Undertow XNIO as well for writing WebSocket messages through the Java WebSocket API (JSR-356), Jetty, and Undertow.

Since:

5.0

Author:

Arjen Poutsma, Violeta Georgieva, Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	AbstractListenerWriteProcessor.State Represents a state for the Subscriber to be in.

Field Summary

Fields

Modifier and Type	Field and Description
protected T	currentData
protected Log	logger
private WriteResultPublisher	resultPublisher
private java.util.concurrent.atomic.AtomicReference<AbstractListenerWriteProcessor.State>	state
private boolean	subscriberCompleted
private Subscription	subscription

Constructor Summary

Constructors

Constructor and Description
AbstractListenerWriteProcessor()

Method Summary

Modifier and Type	Method and Description
void	cancel() Listeners can call this method to cancel further writing.
private boolean	changeState(AbstractListenerWriteProcessor.State oldState, AbstractListenerWriteProcessor.State newState)
protected abstract boolean	isDataEmpty(T data) Whether the given data item contains any actual data to be processed.
protected abstract boolean	isWritePossible() Whether writing is possible.
void	onComplete()
void	onError(java.lang.Throwable t)
void	onNext(T data)
void	onSubscribe(Subscription subscription)
void	onWritePossible() Listeners can call this to notify when writing is possible.
protected void	receiveData(T data) Called when a data item is received via Subscriber#onNext(Object)
protected abstract void	releaseData() Called when the current received data item can be released.
void	subscribe(<any> subscriber)
protected void	suspendWriting() Suspend writing.
protected abstract boolean	write(T data) Writes the given data to the output.
private void	writeIfPossible()
protected void	writingComplete() Invoked when writing is complete.
protected void	writingFailed(java.lang.Throwable ex) Invoked when an error happens while writing.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final Log logger

resultPublisher

private final WriteResultPublisher resultPublisher

state

private final java.util.concurrent.atomic.AtomicReference<AbstractListenerWriteProcessor.State> state

currentData

@Nullable
protected volatile T currentData

subscriberCompleted

private volatile boolean subscriberCompleted

subscription

@Nullable
private Subscription subscription

Constructor Detail

AbstractListenerWriteProcessor

public AbstractListenerWriteProcessor()

Method Detail

onSubscribe

public final void onSubscribe(Subscription subscription)

onNext

public final void onNext(T data)

onError

public final void onError(java.lang.Throwable t)

onComplete

public final void onComplete()

subscribe

public final void subscribe(<any> subscriber)

onWritePossible

public final void onWritePossible()

Listeners can call this to notify when writing is possible.

cancel

public void cancel()

Listeners can call this method to cancel further writing.

receiveData

protected void receiveData(T data)

Called when a data item is received via Subscriber#onNext(Object)

releaseData

protected abstract void releaseData()

Called when the current received data item can be released.

isDataEmpty

protected abstract boolean isDataEmpty(T data)

Whether the given data item contains any actual data to be processed.

isWritePossible

protected abstract boolean isWritePossible()

Whether writing is possible.

write

protected abstract boolean write(T data)
                          throws java.io.IOException

Writes the given data to the output.

Parameters:

data - the data to write

Returns:

whether the data was fully written (true) and new data can be requested, or otherwise (false)

Throws:

java.io.IOException

suspendWriting

protected void suspendWriting()

Suspend writing. Defaults to no-op.

writingComplete

protected void writingComplete()

Invoked when writing is complete. Defaults to no-op.

writingFailed

protected void writingFailed(java.lang.Throwable ex)

Invoked when an error happens while writing.

Defaults to no-op. Servlet 3.1 based implementations will receive javax.servlet.WriteListener#onError(Throwable) event.

changeState

private boolean changeState(AbstractListenerWriteProcessor.State oldState,
                            AbstractListenerWriteProcessor.State newState)

writeIfPossible

private void writeIfPossible()