org.gcube.data.streams.delegates
Class FoldedStream<E>

java.lang.Object
  org.gcube.data.streams.LookAheadStream<E2>
      org.gcube.data.streams.delegates.FoldedStream<E>

Type Parameters:

E - the type of stream element

All Implemented Interfaces:

Iterator<List<E>>, Stream<List<E>>

public class FoldedStream<E>
extends LookAheadStream<E2>

A Stream that folds into lists the elements of another Stream.

Author:

Fabio Simeoni

Field Summary

Fields inherited from class org.gcube.data.streams.LookAheadStream

element, hasNext

Constructor Summary

FoldedStream(Stream<E> stream, int foldSize)
Creates an instance with a Stream and a fold size.

Method Summary

void	close() Closes the stream unconditionally, releasing any resources that it may be using.
protected boolean	delegateHasNext() Returns true if the underlying stream has more elements.
protected List<E>	delegateNext() Returns an element of the underlying stream
boolean	isClosed() Returns true if the stream has been closed.
URI	locator() Returns the stream locator.
void	remove()
protected Stream<E1>	stream() Returns the underlying Stream.

Methods inherited from class org.gcube.data.streams.LookAheadStream

hasNext, next, setHandler

Methods inherited from class java.lang.Object

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

Constructor Detail

FoldedStream

public FoldedStream(Stream<E> stream,
                    int foldSize)
             throws IllegalArgumentException

Creates an instance with a Stream and a fold size.

Parameters:

stream - the stream

foldSize - the fault size

Throws:

IllegalArgumentException - if the stream is null or the size is not positive

Method Detail

delegateNext

protected List<E> delegateNext()

Description copied from class: LookAheadStream

Returns an element of the underlying stream

Specified by:

delegateNext in class LookAheadStream<List<E>>

Returns:

the element

delegateHasNext

protected boolean delegateHasNext()

Description copied from class: LookAheadStream

Returns true if the underlying stream has more elements.

Specified by:

delegateHasNext in class LookAheadStream<List<E>>

Returns:

true if the underlying stream has more elements

stream

protected Stream<E1> stream()

Returns the underlying Stream.

Returns:

the stream

close

public void close()

Description copied from interface: Stream

Closes the stream unconditionally, releasing any resources that it may be using.

Subsequent invocations of this method have no effect.
Subsequents invocations of Stream.hasNext() return false.
Subsequent invocations of Stream.next() throw NoSuchElementExceptions.

Failures are logged by implementations and suppressed otherwise.

locator

public URI locator()
            throws IllegalStateException

Description copied from interface: Stream

Returns the stream locator.

Returns:

the locator

Throws:

IllegalStateException - if the stream is no longer addressable at the time of invocation.

remove

public void remove()

isClosed

public boolean isClosed()

Description copied from interface: Stream

Returns true if the stream has been closed.

Returns:

true if the stream has been closed