xxl.cursors
Class Enumerator

java.lang.Object
  |
  +--xxl.cursors.Enumerator

public class Enumerator

extends java.lang.Object

implements Cursor

The Enumerator-iterator returns a sequence of Integer-objects of a given range.

Field Summary

protected int	from Start of the sequence (inclusive).
protected int	next The value returned by the next call to next() or peek().
protected int	to End of the sequence (exclusive).
protected boolean	up If true the sequence is ascending else the sequence is descending.

Constructor Summary

Enumerator()
Creates an Enumerator object.

Enumerator(int number)
Creates an Enumerator object.

Enumerator(int from, int to)
Creates an Enumerator object.

Method Summary

void	close() Closes the Cursor.
boolean	hasNext() Returns true if the iteration has more elements.
java.lang.Object	next() Returns the next element in the iteration.
java.lang.Object	peek() Shows the next element in the iteration without removing it.
void	remove() Removes from the underlying collection the last element returned by the iterator (optional operation/This method always throws an UnsupportedOperationException).
void	reset() Resets the Cursor to its initial state.
boolean	supportsPeek() Returns true if the peek operation is supported by this PeekIterator (This method returns true.).
void	update(java.lang.Object object) Replaces the object that was returned by the last call to next() or peek() (This method always throws an UnsupportedOperationException).

Methods inherited from class java.lang.Object

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

Field Detail

from

protected int from

Start of the sequence (inclusive).

to

protected int to

End of the sequence (exclusive).

next

protected int next

The value returned by the next call to next() or peek().

up

protected boolean up

If true the sequence is ascending else the sequence is descending.

Constructor Detail

Enumerator

public Enumerator(int from,
                  int to)

Creates an Enumerator object.

Parameters:

from - start of the sequence (inclusive)

to - end of the sequence (inclusive)

Enumerator

public Enumerator(int number)

Creates an Enumerator object. start = 0. end = number.

Parameters:

number - end of the sequence (exclusive)

Enumerator

public Enumerator()

Creates an Enumerator object. start = 0. end = Integer.MAX_VALUE.

Method Detail

close

public void close()

Closes the Cursor. Signals the cursor to cleanup resources, close files, etc. After a call to close() calls to methods like next() or peek() are not guarantied to yield proper results.

Specified by:

close in interface Cursor

hasNext

public boolean hasNext()

Returns true if the iteration has more elements.

Specified by:

hasNext in interface Cursor

Returns:

true if the iterator has more elements.

next

public java.lang.Object next()
                      throws java.util.NoSuchElementException

Returns the next element in the iteration.

Specified by:

next in interface Cursor

Returns:

the next element in the iteration.

Throws:

java.util.NoSuchElementException - iteration has no more elements.

peek

public java.lang.Object peek()
                      throws java.lang.UnsupportedOperationException

Shows the next element in the iteration without removing it.

Specified by:

peek in interface Cursor

Returns:

the next element in the iteration.

Throws:

java.util.NoSuchElementException - iteration has no more elements.

java.lang.UnsupportedOperationException - if the peek operation is not supported by this PeekIterator.

remove

public void remove()
            throws java.lang.UnsupportedOperationException

Removes from the underlying collection the last element returned by the iterator (optional operation/This method always throws an UnsupportedOperationException).

Specified by:

remove in interface Cursor

Throws:

java.lang.IllegalStateException - if the next method has not yet been called, or the remove method has already been called after the last call to the next method.

java.lang.UnsupportedOperationException - if the remove operation is not supported by this PeekIterator.

reset

public void reset()
           throws java.lang.UnsupportedOperationException

Resets the Cursor to its initial state.

Specified by:

reset in interface Cursor

supportsPeek

public boolean supportsPeek()

Returns true if the peek operation is supported by this PeekIterator (This method returns true.).

Specified by:

supportsPeek in interface Cursor

Returns:

true if the peek operation is supported by this PeekIterator.

update

public void update(java.lang.Object object)
            throws java.lang.UnsupportedOperationException

Replaces the object that was returned by the last call to next() or peek() (This method always throws an UnsupportedOperationException). This operation must not be called after a call to hasNext(). It should follow a call to next() or peek().

Specified by:

update in interface Cursor

Parameters:

object - the object that replaces the object returned by the last call to next() or peek()