org.apache.commons.betwixt.expression
Class IteratorExpression.EnumerationIterator

java.lang.Object
  org.apache.commons.betwixt.expression.IteratorExpression.EnumerationIterator

All Implemented Interfaces:

java.util.Iterator

Enclosing class:

IteratorExpression

private static final class IteratorExpression.EnumerationIterator

extends java.lang.Object

implements java.util.Iterator

Adapter to make Enumerationinstances appear to be Iteratorinstances. Originated in commons-collections. Added as a private inner class to break dependency.

Author:

James Strachan , Daniel Rall

Field Summary

private java.util.Collection	collection The collection to remove elements from
private java.util.Enumeration	enumeration The enumeration being converted
private java.lang.Object	last The last object retrieved

Constructor Summary

IteratorExpression.EnumerationIterator()
Constructs a new EnumerationIterator that will not function until setEnumeration(Enumeration) is called.

IteratorExpression.EnumerationIterator(java.util.Enumeration enumeration)
Constructs a new EnumerationIterator that provides an iterator view of the given enumeration.

IteratorExpression.EnumerationIterator(java.util.Enumeration enumeration, java.util.Collection collection)
Constructs a new EnumerationIterator that will remove elements from the specified collection.

Method Summary

java.util.Enumeration	getEnumeration() Returns the underlying enumeration.
boolean	hasNext() Returns true if the underlying enumeration has more elements.
java.lang.Object	next() Returns the next object from the enumeration.
void	remove() Removes the last retrieved element if a collection is attached.
void	setEnumeration(java.util.Enumeration enumeration) Sets the underlying enumeration.

Methods inherited from class java.lang.Object

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

Field Detail

collection

private java.util.Collection collection

The collection to remove elements from

enumeration

private java.util.Enumeration enumeration

The enumeration being converted

last

private java.lang.Object last

The last object retrieved

Constructor Detail

IteratorExpression.EnumerationIterator

public IteratorExpression.EnumerationIterator()

Constructs a new EnumerationIterator that will not function until setEnumeration(Enumeration) is called.

IteratorExpression.EnumerationIterator

public IteratorExpression.EnumerationIterator(java.util.Enumeration enumeration)

Constructs a new EnumerationIterator that provides an iterator view of the given enumeration.

Parameters:

enumeration - the enumeration to use

IteratorExpression.EnumerationIterator

public IteratorExpression.EnumerationIterator(java.util.Enumeration enumeration,
                                              java.util.Collection collection)

Constructs a new EnumerationIterator that will remove elements from the specified collection.

Parameters:

enumeration - the enumeration to use

collection - the collection to remove elements form

Method Detail

hasNext

public boolean hasNext()

Returns true if the underlying enumeration has more elements.

Specified by:

hasNext in interface java.util.Iterator

Returns:

true if the underlying enumeration has more elements

Throws:

java.lang.NullPointerException - if the underlying enumeration is null

next

public java.lang.Object next()

Returns the next object from the enumeration.

Specified by:

next in interface java.util.Iterator

Returns:

the next object from the enumeration

Throws:

java.lang.NullPointerException - if the enumeration is null

remove

public void remove()

Removes the last retrieved element if a collection is attached.

Functions if an associated Collection is known. If so, the first occurrence of the last returned object from this iterator will be removed from the collection.

Specified by:

remove in interface java.util.Iterator

Throws:

java.lang.IllegalStateException - next() not called.

java.lang.UnsupportedOperationException - if no associated collection

getEnumeration

public java.util.Enumeration getEnumeration()

Returns the underlying enumeration.

Returns:

the underlying enumeration

setEnumeration

public void setEnumeration(java.util.Enumeration enumeration)

Sets the underlying enumeration.

Parameters:

enumeration - the new underlying enumeration