TreeList ("The Adobe AEM Quickstart and Web Application.")

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractList<E>
  - - org.apache.commons.collections4.list.TreeList<E>

All Implemented Interfaces:

java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>
```
public class TreeList<E>
extends java.util.AbstractList<E>
```
A List implementation that is optimised for fast insertions and removals at any index in the list.
This list implementation utilises a tree structure internally to ensure that all insertions and removals are O(log n). This provides much faster performance than both an ArrayList and a LinkedList where elements are inserted and removed repeatedly from anywhere in the list.
The following relative performance statistics are indicative of this class:
```
              get  add  insert  iterate  remove
 TreeList       3    5       1       2       1
 ArrayList      1    1      40       1      40
 LinkedList  5800    1     350       2     325
 
```
ArrayList is a good general purpose list implementation. It is faster than TreeList for most operations except inserting and removing in the middle of the list. ArrayList also uses less memory as TreeList uses one object per entry.
LinkedList is rarely a good choice of implementation. TreeList is almost always a good replacement for it, although it does use slightly more memory.
Since:

3.1

Constructor Summary

Constructors
Constructor and Description
`TreeList()` Constructs a new empty list.
`TreeList(java.util.Collection<? extends E> coll)` Constructs a new empty list that copies the specified collection.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(int index, E obj)` Adds a new element to the list.
`boolean`	`addAll(java.util.Collection<? extends E> c)` Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's Iterator.
`void`	`clear()` Clears the list, removing all entries.
`boolean`	`contains(java.lang.Object object)` Searches for the presence of an object in the list.
`E`	`get(int index)` Gets the element at the specified index.
`int`	`indexOf(java.lang.Object object)` Searches for the index of an object in the list.
`java.util.Iterator<E>`	`iterator()` Gets an iterator over the list.
`java.util.ListIterator<E>`	`listIterator()` Gets a ListIterator over the list.
`java.util.ListIterator<E>`	`listIterator(int fromIndex)` Gets a ListIterator over the list.
`E`	`remove(int index)` Removes the element at the specified index.
`E`	`set(int index, E obj)` Sets the element at the specified index.
`int`	`size()` Gets the current size of the list.
`java.lang.Object[]`	`toArray()` Converts the list into an array.

Methods inherited from class java.util.AbstractList
add, addAll, equals, hashCode, lastIndexOf, subList

Methods inherited from class java.util.AbstractCollection
containsAll, isEmpty, remove, removeAll, retainAll, toArray, toString

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List
containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable
forEach

- Constructor Detail
  - TreeList
```
public TreeList()
```
    Constructs a new empty list.
  - TreeList
```
public TreeList(java.util.Collection<? extends E> coll)
```
    Constructs a new empty list that copies the specified collection.
    
    Parameters:
    
    coll - the collection to copy
    
    Throws:
    
    java.lang.NullPointerException - if the collection is null
- Method Detail
  - get
```
public E get(int index)
```
    Gets the element at the specified index.
    
    Specified by:
    
    get in interface java.util.List<E>
    
    Specified by:
    
    get in class java.util.AbstractList<E>
    
    Parameters:
    
    index - the index to retrieve
    
    Returns:
    
    the element at the specified index
  - size
```
public int size()
```
    Gets the current size of the list.
    
    Specified by:
    
    size in interface java.util.Collection<E>
    
    Specified by:
    
    size in interface java.util.List<E>
    
    Specified by:
    
    size in class java.util.AbstractCollection<E>
    
    Returns:
    
    the current size
  - iterator
```
public java.util.Iterator<E> iterator()
```
    Gets an iterator over the list.
    
    Specified by:
    
    iterator in interface java.lang.Iterable<E>
    
    Specified by:
    
    iterator in interface java.util.Collection<E>
    
    Specified by:
    
    iterator in interface java.util.List<E>
    
    Overrides:
    
    iterator in class java.util.AbstractList<E>
    
    Returns:
    
    an iterator over the list
  - listIterator
```
public java.util.ListIterator<E> listIterator()
```
    Gets a ListIterator over the list.
    
    Specified by:
    
    listIterator in interface java.util.List<E>
    
    Overrides:
    
    listIterator in class java.util.AbstractList<E>
    
    Returns:
    
    the new iterator
  - listIterator
```
public java.util.ListIterator<E> listIterator(int fromIndex)
```
    Gets a ListIterator over the list.
    
    Specified by:
    
    listIterator in interface java.util.List<E>
    
    Overrides:
    
    listIterator in class java.util.AbstractList<E>
    
    Parameters:
    
    fromIndex - the index to start from
    
    Returns:
    
    the new iterator
  - indexOf
```
public int indexOf(java.lang.Object object)
```
    Searches for the index of an object in the list.
    
    Specified by:
    
    indexOf in interface java.util.List<E>
    
    Overrides:
    
    indexOf in class java.util.AbstractList<E>
    
    Parameters:
    
    object - the object to search
    
    Returns:
    
    the index of the object, -1 if not found
  - contains
```
public boolean contains(java.lang.Object object)
```
    Searches for the presence of an object in the list.
    
    Specified by:
    
    contains in interface java.util.Collection<E>
    
    Specified by:
    
    contains in interface java.util.List<E>
    
    Overrides:
    
    contains in class java.util.AbstractCollection<E>
    
    Parameters:
    
    object - the object to check
    
    Returns:
    
    true if the object is found
  - toArray
```
public java.lang.Object[] toArray()
```
    Converts the list into an array.
    
    Specified by:
    
    toArray in interface java.util.Collection<E>
    
    Specified by:
    
    toArray in interface java.util.List<E>
    
    Overrides:
    
    toArray in class java.util.AbstractCollection<E>
    
    Returns:
    
    the list as an array
  - add
```
public void add(int index,
                E obj)
```
    Adds a new element to the list.
    
    Specified by:
    
    add in interface java.util.List<E>
    
    Overrides:
    
    add in class java.util.AbstractList<E>
    
    Parameters:
    
    index - the index to add before
    
    obj - the element to add
  - addAll
```
public boolean addAll(java.util.Collection<? extends E> c)
```
    Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's Iterator.
    This method runs in O(n + log m) time, where m is the size of this list and n is the size of c.
    
    Specified by:
    
    addAll in interface java.util.Collection<E>
    
    Specified by:
    
    addAll in interface java.util.List<E>
    
    Overrides:
    
    addAll in class java.util.AbstractCollection<E>
    
    Parameters:
    
    c - the collection to be added to this list
    
    Returns:
    
    true if this list changed as a result of the call
    
    Throws:
    
    java.lang.NullPointerException
  - set
```
public E set(int index,
             E obj)
```
    Sets the element at the specified index.
    
    Specified by:
    
    set in interface java.util.List<E>
    
    Overrides:
    
    set in class java.util.AbstractList<E>
    
    Parameters:
    
    index - the index to set
    
    obj - the object to store at the specified index
    
    Returns:
    
    the previous object at that index
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is invalid
  - remove
```
public E remove(int index)
```
    Removes the element at the specified index.
    
    Specified by:
    
    remove in interface java.util.List<E>
    
    Overrides:
    
    remove in class java.util.AbstractList<E>
    
    Parameters:
    
    index - the index to remove
    
    Returns:
    
    the previous object at that index
  - clear
```
public void clear()
```
    Clears the list, removing all entries.
    
    Specified by:
    
    clear in interface java.util.Collection<E>
    
    Specified by:
    
    clear in interface java.util.List<E>
    
    Overrides:
    
    clear in class java.util.AbstractList<E>

Class TreeList<E>

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractList

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.List

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Constructor Detail

TreeList

TreeList

Method Detail

get

size

iterator

listIterator

listIterator

indexOf

contains

toArray

add

addAll

set

remove

clear