# Class TransformedList<E>

java.lang.Object
org.apache.commons.collections4.collection.AbstractCollectionDecorator<E>
org.apache.commons.collections4.collection.TransformedCollection<E>
org.apache.commons.collections4.list.TransformedList<E>

Type Parameters:
  `E` - the type of the elements in the list.

All Implemented Interfaces:
  `Serializable`, `Iterable<E>`, `Collection<E>`, `List<E>`

public class TransformedList<E> extends TransformedCollection<E> implements List<E>
Decorates another `List` to transform objects that are added.

The add and set methods are affected by this class. Thus objects must be removed or searched for using their transformed form. For example, if the transformation converts Strings to Integers, you must use the Integer form to remove objects.

This class is Serializable from Commons Collections 3.1.

Since:
  3.0
See Also:
  - Serialized Form

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `protected class`
  `TransformedList.TransformedListIterator`
  Inner class Iterator for the TransformedList

- ## Field Summary

  ### Fields inherited from class org.apache.commons.collections4.collection.TransformedCollection

  `transformer`

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  `protected`
  `TransformedList(List<E> list, Transformer<? super E,? extends E> transformer)`
  Constructor that wraps (not copies).

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `add(int index, E object)`
  `boolean`
  `addAll(int index, Collection<? extends E> coll)`
  `boolean`
  `equals(Object object)`
  `E`
  `get(int index)`
  `protected List<E>`
  `getList()`
  Gets the decorated list.
  `int`
  `hashCode()`
  `int`
  `indexOf(Object object)`
  `int`
  `lastIndexOf(Object object)`
  `ListIterator<E>`
  `listIterator()`
  `ListIterator<E>`
  `listIterator(int i)`
  `E`
  `remove(int index)`
  `E`
  `set(int index, E object)`
  `List<E>`
  `subList(int fromIndex, int toIndex)`
  `static <E> TransformedList<E>`
  `transformedList(List<E> list, Transformer<? super E,? extends E> transformer)`
  Factory method to create a transforming list that will transform existing contents of the specified list.
  `static <E> TransformedList<E>`
  `transformingList(List<E> list, Transformer<? super E,? extends E> transformer)`
  Factory method to create a transforming list.

  ### Methods inherited from class org.apache.commons.collections4.collection.TransformedCollection

  `add, addAll, transform, transform, transformedCollection, transformingCollection`

  ### Methods inherited from class org.apache.commons.collections4.collection.AbstractCollectionDecorator

  `clear, contains, containsAll, decorated, isEmpty, iterator, remove, removeAll, removeIf, retainAll, setCollection, size, toArray, toArray, toString`

  ### Methods inherited from class java.lang.Object

  `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

  ### Methods inherited from interface java.util.Collection

  `parallelStream, removeIf, stream`

  ### Methods inherited from interface java.lang.Iterable

  `forEach`

  ### Methods inherited from interface java.util.List

  `add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, replaceAll, retainAll, size, sort, spliterator, toArray, toArray`

- ## Constructor Details

  - ### TransformedList

    protected TransformedList(List<E> list, Transformer<? super E,? extends E> transformer)
    Constructor that wraps (not copies).

    If there are any elements already in the list being decorated, they are NOT transformed.

    Parameters:
      `list` - the list to decorate, must not be null
      `transformer` - the transformer to use for conversion, must not be null
    Throws:
      `NullPointerException` - if list or transformer is null

- ## Method Details

  - ### transformedList

    public static <E> TransformedList<E> transformedList(List<E> list, Transformer<? super E,? extends E> transformer)
    Factory method to create a transforming list that will transform existing contents of the specified list.

    If there are any elements already in the list being decorated, they will be transformed by this method. Contrast this with `transformingList(List, Transformer)`.

    Type Parameters:
      `E` - the type of the elements in the list
    Parameters:
      `list` - the list to decorate, must not be null
      `transformer` - the transformer to use for conversion, must not be null
    Returns:
      a new transformed List
    Throws:
      `NullPointerException` - if list or transformer is null
    Since:
      4.0

  - ### transformingList

    public static <E> TransformedList<E> transformingList(List<E> list, Transformer<? super E,? extends E> transformer)
    Factory method to create a transforming list.

    If there are any elements already in the list being decorated, they are NOT transformed. Contrast this with `transformedList(List, Transformer)`.

    Type Parameters:
      `E` - the type of the elements in the list
    Parameters:
      `list` - the list to decorate, must not be null
      `transformer` - the transformer to use for conversion, must not be null
    Returns:
      a new transformed list
    Throws:
      `NullPointerException` - if list or transformer is null
    Since:
      4.0

  - ### add

    public void add(int index, E object)
    Specified by:
      `add` in interface `List<E>`

  - ### addAll

    public boolean addAll(int index, Collection<? extends E> coll)
    Specified by:
      `addAll` in interface `List<E>`

  - ### equals

    public boolean equals(Object object)
    Specified by:
      `equals` in interface `Collection<E>`
    Specified by:
      `equals` in interface `List<E>`
    Overrides:
      `equals` in class `Object`

  - ### get

    public E get(int index)
    Specified by:
      `get` in interface `List<E>`

  - ### getList

    protected List<E> getList()
    Gets the decorated list.
    Returns:
      the decorated list

  - ### hashCode

    public int hashCode()
    Specified by:
      `hashCode` in interface `Collection<E>`
    Specified by:
      `hashCode` in interface `List<E>`
    Overrides:
      `hashCode` in class `Object`

  - ### indexOf

    public int indexOf(Object object)
    Specified by:
      `indexOf` in interface `List<E>`

  - ### lastIndexOf

    public int lastIndexOf(Object object)
    Specified by:
      `lastIndexOf` in interface `List<E>`

  - ### listIterator

    public ListIterator<E> listIterator()
    Specified by:
      `listIterator` in interface `List<E>`

  - ### listIterator

    public ListIterator<E> listIterator(int i)
    Specified by:
      `listIterator` in interface `List<E>`

  - ### remove

    public E remove(int index)
    Specified by:
      `remove` in interface `List<E>`

  - ### set

    public E set(int index, E object)
    Specified by:
      `set` in interface `List<E>`

  - ### subList

    public List<E> subList(int fromIndex, int toIndex)
    Specified by:
      `subList` in interface `List<E>`