Module org.apache.jena.base

Package org.apache.jena.atlas.iterator

Class IteratorWithHistory<T>

java.lang.Object

org.apache.jena.atlas.iterator.IteratorWithHistory<T>

All Implemented Interfaces:

Iterator<T>, IteratorCloseable<T>, Closeable

public class IteratorWithHistory<T>
extends Object
implements IteratorCloseable<T>

Remembers the last N yields. See also IteratorWithBuffer, for an iterator that looks ahead to what it will yield. History is retained at the end of iterator. "Close" releases the history.

See Also:

• IteratorWithBuffer
• PeekIterator
• PushbackIterator

Constructor Summary

Constructors

Constructor	Description
IteratorWithHistory(Iterator<T> iter, int N)

Method Summary

Modifier and Type	Method	Description
void	close()
int	currentSize()	Return the current size of the history.
T	getPrevious(int idx)	return the previous i'th element returned by next().
boolean	hasNext()
T	next()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Details

IteratorWithHistory

public IteratorWithHistory(Iterator<T> iter,
 int N)

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<T>

next

public T next()

Specified by:

next in interface Iterator<T>

getPrevious

public T getPrevious(int idx)

return the previous i'th element returned by next(). 0 means last call of next. History is retained after the end of iteration.

Returns:

Element or null for no such element (that is for haven't yielded that many elements).

Throws:

IndexOutOfBoundsException - if index is negative.

currentSize

public int currentSize()

Return the current size of the history. This can be used to tell the difference between an iterator returning null and an iterator that is just short.

close

public void close()

Specified by:

close in interface Closeable