com.blacklocus.qs

Interface QueueItemProvider<Q>

All Superinterfaces:

java.lang.Iterable<java.util.Collection<Q>>, java.util.Iterator<java.util.Collection<Q>>

All Known Subinterfaces:

MessageProvider

All Known Implementing Classes:

BatchingQuIP, ExternalQueueItemProvider, LineReaderQuIP, OneAtATimeQueueItemProvider, RestartingQueueItemProvider

public interface QueueItemProvider<Q>
extends java.util.Iterator<java.util.Collection<Q>>, java.lang.Iterable<java.util.Collection<Q>>

The superest class inside of the com.blacklocus.qs namespace which can provide items to a QueueReader. Note that the QueueReader actually accepts any Iterable<Collection<Q>> provider, so this is useful more as a marker interface.

Method Summary

Modifier and Type	Method and Description
boolean	hasNext()
java.util.Iterator<java.util.Collection<Q>>	iterator() Generally returns this.
java.util.Collection<Q>	next()
void	remove() A means to delete the message because it is done or should not be processed again.

Methods inherited from interface java.util.Iterator

forEachRemaining

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

hasNext

boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<java.util.Collection<Q>>

Returns:

true if the reading QueueReader should continue processing messages from this provider.

next

java.util.Collection<Q> next()

Specified by:

next in interface java.util.Iterator<java.util.Collection<Q>>

Returns:

the next batch of messages, or an empty collection if none were available. Should never return null. The reading QueueReader may sleep after receiving an empty batch depending on its configuration.

remove

void remove()

A means to delete the message because it is done or should not be processed again. If the provider does not care or has no such notion, should not throw an exception. An exception may be thrown if the provider does recognize remove semantics, but somehow failed in executing that intention.

Specified by:

remove in interface java.util.Iterator<java.util.Collection<Q>>

iterator

java.util.Iterator<java.util.Collection<Q>> iterator()

Generally returns this. QueueItemProviders are not generally reusable/resettable since the underlying message source will often not be reversible. Mashing the two interfaces together simplifies implementations a bit, and also supports any typical Iterable usage.

Specified by:

iterator in interface java.lang.Iterable<java.util.Collection<Q>>