Package com.mongodb.stitch.android.services.mongodb.remote

Class AsyncChangeStream<DocumentT,ChangeEventT extends BaseChangeEvent<DocumentT>>

java.lang.Object

com.mongodb.stitch.android.services.mongodb.remote.AsyncChangeStream<DocumentT,ChangeEventT>

Type Parameters:

DocumentT - The type of the full document on the underlying change event to be returned asynchronously.

ChangeEventT - The type of MongoDB change event that this stream internally returns.

public class AsyncChangeStream<DocumentT,ChangeEventT extends BaseChangeEvent<DocumentT>>
extends Object

An implementation of ChangeStream that returns each event as a Task.

Constructor Summary

Constructors

Constructor	Description
AsyncChangeStream(ChangeStream<ChangeEventT> stream, TaskDispatcher dispatcher)	Initializes a passthrough change stream with the provided underlying event stream.

Method Summary

Modifier and Type	Method	Description
void	addChangeEventListener(BaseChangeEventListener<DocumentT,ChangeEventT> listener)	Adds a ChangeEventListener to the ChangeStream that will run on every event on the stream.
void	close()	Closes the underlying stream and removes all ChangeEventListeners.
boolean	isOpen()	Indicates whether or not the change stream is currently open.
Task<ChangeEventT>	nextEvent()	Returns a Task whose resolution gives the next event from the underlying stream.
void	removeChangeEventListener(BaseChangeEventListener<DocumentT,ChangeEventT> listener)	Remove a ChangeEventListener from the ChangeStream.
void	setExceptionListener(ExceptionListener exceptionListener)	Optionally adds a listener that is notified when an attempt to retrieve the next event.

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncChangeStream

public AsyncChangeStream(ChangeStream<ChangeEventT> stream,
                         TaskDispatcher dispatcher)

Initializes a passthrough change stream with the provided underlying event stream.

Parameters:

stream - The event stream.

dispatcher - The event dispatcher.

Method Detail

addChangeEventListener

public void addChangeEventListener(BaseChangeEventListener<DocumentT,ChangeEventT> listener)

Adds a ChangeEventListener to the ChangeStream that will run on every event on the stream. Multiple ChangeEventListeners can be added to any given stream and they will be removed when the stream is closed or when the listener is removed. Calls to nextEvent() will fail while there exists any ChangeEventListener's on this stream. Additionally, any events that occur after the ChangeEventListener is opened will not be caught by the listener.

Parameters:

listener - the BaseChangeEventListener

removeChangeEventListener

public void removeChangeEventListener(BaseChangeEventListener<DocumentT,ChangeEventT> listener)

Remove a ChangeEventListener from the ChangeStream.

Parameters:

listener - the BaseChangeEventListener

close

public void close()
           throws IOException

Closes the underlying stream and removes all ChangeEventListeners.

Throws:

IOException - If the underlying stream throws an IOException when it is closed.

setExceptionListener

public void setExceptionListener(ExceptionListener exceptionListener)

Optionally adds a listener that is notified when an attempt to retrieve the next event. fails.

Parameters:

exceptionListener - The ExceptionListener.

isOpen

public boolean isOpen()

Indicates whether or not the change stream is currently open.

Returns:

True if the underlying change stream is open.

nextEvent

public Task<ChangeEventT> nextEvent()
                             throws IOException,
                                    IllegalStateException

Returns a Task whose resolution gives the next event from the underlying stream.

Returns:

task providing the next event

Throws:

IOException - if the underlying stream throws an IOException

IllegalStateException - if any ChangeEventListeners are running