FilterListIterator

java.lang.Object
- org.apache.commons.collections4.iterators.FilterListIterator<E>

All Implemented Interfaces:

java.util.Iterator<E>, java.util.ListIterator<E>
```
public class FilterListIterator<E>
extends java.lang.Object
implements java.util.ListIterator<E>
```
Decorates another ListIterator using a predicate to filter elements.
This iterator decorates the underlying iterator, only allowing through those elements that match the specified Predicate.

Since:

2.0

Version:

$Id: FilterListIterator.java 1477802 2013-04-30 20:01:28Z tn $

Field Summary

Fields
Modifier and Type	Field and Description
`private java.util.ListIterator<? extends E>`	`iterator` The iterator being used
`private int`	`nextIndex` The index of the element that would be returned by `next()`.
`private E`	`nextObject` The value of the next (matching) object, when `nextObjectSet` is true.
`private boolean`	`nextObjectSet` Whether or not the `nextObject` has been set (possibly to `null`).
`private Predicate<? super E>`	`predicate` The predicate being used
`private E`	`previousObject` The value of the previous (matching) object, when `previousObjectSet` is true.
`private boolean`	`previousObjectSet` Whether or not the `previousObject` has been set (possibly to `null`).

Constructor Summary

Constructors
Constructor and Description
`FilterListIterator()` Constructs a new `FilterListIterator` that will not function until `setListIterator` and `setPredicate` are invoked.
`FilterListIterator(java.util.ListIterator<? extends E> iterator)` Constructs a new `FilterListIterator` that will not function until `setPredicate` is invoked.
`FilterListIterator(java.util.ListIterator<? extends E> iterator, Predicate<? super E> predicate)` Constructs a new `FilterListIterator`.
`FilterListIterator(Predicate<? super E> predicate)` Constructs a new `FilterListIterator` that will not function until `setListIterator` is invoked.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(E o)` Not supported.
`private void`	`clearNextObject()`
`private void`	`clearPreviousObject()`
`java.util.ListIterator<? extends E>`	`getListIterator()` Gets the iterator this iterator is using.
`Predicate<? super E>`	`getPredicate()` Gets the predicate this iterator is using.
`boolean`	`hasNext()`
`boolean`	`hasPrevious()`
`E`	`next()`
`int`	`nextIndex()`
`E`	`previous()`
`int`	`previousIndex()`
`void`	`remove()` Not supported.
`void`	`set(E o)` Not supported.
`void`	`setListIterator(java.util.ListIterator<? extends E> iterator)` Sets the iterator for this iterator to use.
`private boolean`	`setNextObject()`
`void`	`setPredicate(Predicate<? super E> predicate)` Sets the predicate this the iterator to use.
`private boolean`	`setPreviousObject()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Iterator
forEachRemaining

- Field Detail
  - iterator
```
private java.util.ListIterator<? extends E> iterator
```
    The iterator being used
  - predicate
```
private Predicate<? super E> predicate
```
    The predicate being used
  - nextObject
```
private E nextObject
```
    The value of the next (matching) object, when nextObjectSet is true.
  - nextObjectSet
```
private boolean nextObjectSet
```
    Whether or not the nextObject has been set (possibly to null).
  - previousObject
```
private E previousObject
```
    The value of the previous (matching) object, when previousObjectSet is true.
  - previousObjectSet
```
private boolean previousObjectSet
```
    Whether or not the previousObject has been set (possibly to null).
  - nextIndex
```
private int nextIndex
```
    The index of the element that would be returned by next().
- Constructor Detail
  - FilterListIterator
```
public FilterListIterator()
```
    Constructs a new FilterListIterator that will not function until setListIterator and setPredicate are invoked.
  - FilterListIterator
```
public FilterListIterator(java.util.ListIterator<? extends E> iterator)
```
    Constructs a new FilterListIterator that will not function until setPredicate is invoked.
    
    Parameters:
    
    iterator - the iterator to use
  - FilterListIterator
```
public FilterListIterator(java.util.ListIterator<? extends E> iterator,
                          Predicate<? super E> predicate)
```
    Constructs a new FilterListIterator.
    
    Parameters:
    
    iterator - the iterator to use
    
    predicate - the predicate to use
  - FilterListIterator
```
public FilterListIterator(Predicate<? super E> predicate)
```
    Constructs a new FilterListIterator that will not function until setListIterator is invoked.
    
    Parameters:
    
    predicate - the predicate to use.
- Method Detail
  - add
```
public void add(E o)
```
    Not supported.
    
    Specified by:
    
    add in interface java.util.ListIterator<E>
  - hasNext
```
public boolean hasNext()
```
    Specified by:
    
    hasNext in interface java.util.Iterator<E>
    
    Specified by:
    
    hasNext in interface java.util.ListIterator<E>
  - hasPrevious
```
public boolean hasPrevious()
```
    Specified by:
    
    hasPrevious in interface java.util.ListIterator<E>
  - next
```
public E next()
```
    Specified by:
    
    next in interface java.util.Iterator<E>
    
    Specified by:
    
    next in interface java.util.ListIterator<E>
  - nextIndex
```
public int nextIndex()
```
    Specified by:
    
    nextIndex in interface java.util.ListIterator<E>
  - previous
```
public E previous()
```
    Specified by:
    
    previous in interface java.util.ListIterator<E>
  - previousIndex
```
public int previousIndex()
```
    Specified by:
    
    previousIndex in interface java.util.ListIterator<E>
  - remove
```
public void remove()
```
    Not supported.
    
    Specified by:
    
    remove in interface java.util.Iterator<E>
    
    Specified by:
    
    remove in interface java.util.ListIterator<E>
  - set
```
public void set(E o)
```
    Not supported.
    
    Specified by:
    
    set in interface java.util.ListIterator<E>
  - getListIterator
```
public java.util.ListIterator<? extends E> getListIterator()
```
    Gets the iterator this iterator is using.
    
    Returns:
    
    the iterator.
  - setListIterator
```
public void setListIterator(java.util.ListIterator<? extends E> iterator)
```
    Sets the iterator for this iterator to use. If iteration has started, this effectively resets the iterator.
    
    Parameters:
    
    iterator - the iterator to use
  - getPredicate
```
public Predicate<? super E> getPredicate()
```
    Gets the predicate this iterator is using.
    
    Returns:
    
    the predicate.
  - setPredicate
```
public void setPredicate(Predicate<? super E> predicate)
```
    Sets the predicate this the iterator to use.
    
    Parameters:
    
    predicate - the transformer to use
  - clearNextObject
```
private void clearNextObject()
```
  - setNextObject
```
private boolean setNextObject()
```
  - clearPreviousObject
```
private void clearPreviousObject()
```
  - setPreviousObject
```
private boolean setPreviousObject()
```

Class FilterListIterator<E>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Iterator

Field Detail

iterator

predicate

nextObject

nextObjectSet

previousObject

previousObjectSet

nextIndex

Constructor Detail

FilterListIterator

FilterListIterator

FilterListIterator

FilterListIterator

Method Detail

add

hasNext

hasPrevious

next

nextIndex

previous

previousIndex

remove

set

getListIterator

setListIterator

getPredicate

setPredicate

clearNextObject

setNextObject

clearPreviousObject

setPreviousObject