Package io.permazen.util

Interface CloseableIterator<E>

Type Parameters:

E - iteration element type

All Superinterfaces:

AutoCloseable, Closeable, Iterator<E>

All Known Implementing Classes:

AbstractKVIterator, BerkeleyKVTransaction.CursorIterator, CursorIterator, KVPairIterator, UniqueIterator

public interface CloseableIterator<E>
extends Iterator<E>, Closeable

An Iterator that is Closeable and can be close()'d without throwing any exceptions.

Method Summary

Modifier and Type	Method	Description
void	close()
static <E> CloseableIterator<E>	emptyIterator()	Return an empty CloseableIterator.
default Stream<E>	toStream()	Create a Stream from this iterator, and arrange for this iterator to be closed when the stream is closed.
static <E> CloseableIterator<E>	wrap(Iterator<E> iterator)	Wrap the given plain Iterator as necessary to make it a CloseableIterator.
static <E> CloseableIterator<E>	wrap(Iterator<E> iterator, AutoCloseable resource)	Wrap the given plain Iterator to make it a CloseableIterator, such that when close() is invoked, the associated resource is closed.

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Method Details

close

void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

wrap

static <E> CloseableIterator<E> wrap(Iterator<E> iterator)

Wrap the given plain Iterator as necessary to make it a CloseableIterator.

If iterator already implements CloseableIterator, then iterator is returned.

If iterator does not implement CloseableIterator but does implement Closeable (or AutoCloseable), then the returned instance will delegate to iterator.close() when close() is invoked, and any exception thrown will be discarded.

Otherwise, invoking close() on the returned instance does nothing.

Type Parameters:

E - iteration element type

Parameters:

iterator - nested iterator

Returns:

CloseableIterator wrapping iterator, or null if iterator is null

wrap

static <E> CloseableIterator<E> wrap(Iterator<E> iterator,
 AutoCloseable resource)

Wrap the given plain Iterator to make it a CloseableIterator, such that when close() is invoked, the associated resource is closed.

Type Parameters:

E - iteration element type

Parameters:

iterator - nested iterator

resource - resource to close when the returned instance is close()'d, or null to do nothing on close()

Returns:

CloseableIterator wrapping iterator, or null if iterator is null

emptyIterator

static <E> CloseableIterator<E> emptyIterator()

Return an empty CloseableIterator.

Returns:

empty CloseableIterator

toStream

default Stream<E> toStream()

Create a Stream from this iterator, and arrange for this iterator to be closed when the stream is closed.

Returns:

this instance wrapped as a Stream