Package org.forgerock.util

Class LazyList<E>

java.lang.Object
org.forgerock.util.LazyList<E>
Type Parameters:
E - The type of element contained in this list.
All Implemented Interfaces:
Iterable<E>, Collection<E>, List<E>
public class LazyList<E> extends Object implements List<E>
A list with lazy initialization. The factory is called to initialize the list on the first call to one of this object's methods.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected Factory<List<E>>
    factory
    Factory to create the instance of the list to expose.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    LazyList()
    Constructs a new lazy list.
     
    LazyList(Factory<List<E>> factory)
    Constructs a new lazy list.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(int index, E element)
    Inserts the specified element at the specified position in this list.
    boolean
    add(E e)
    Appends the specified element to the end of this list.
    boolean
    addAll(int index, Collection<? extends E> c)
    Inserts all of the elements in the specified collection into this list at the specified position.
    boolean
    addAll(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()
    Removes all of the elements from this list.
    boolean
    contains(Object o)
    Returns true if this list contains the specified element.
    boolean
    containsAll(Collection<?> c)
    Returns true if this list contains all of the elements of the specified collection.
    boolean
    equals(Object o)
    Compares the specified object with this list for equality.
    E
    get(int index)
    Returns the element at the specified position in this list.
    int
    hashCode()
    Returns the hash code value for this list.
    int
    indexOf(Object o)
    Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
    boolean
    isEmpty()
    Returns true if this list contains no elements.
    Iterator<E>
    iterator()
    Returns an iterator over the elements in this list in proper sequence.
    int
    lastIndexOf(Object o)
    Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
    ListIterator<E>
    listIterator()
    Returns a list iterator over the elements in this list (in proper sequence).
    ListIterator<E>
    listIterator(int index)
    Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list.
    E
    remove(int index)
    Removes the element at the specified position in this list.
    boolean
    remove(Object o)
    Removes the first occurrence of the specified element from this list, if it is present.
    boolean
    removeAll(Collection<?> c)
    Removes from this list all of its elements that are contained in the specified collection.
    boolean
    retainAll(Collection<?> c)
    Retains only the elements in this list that are contained in the specified collection.
    E
    set(int index, E element)
    Replaces the element at the specified position in this list with the specified element.
    int
    size()
    Returns the number of elements in this list.
    List<E>
    subList(int fromIndex, int toIndex)
    Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
    Object[]
    toArray()
    Returns an array containing all of the elements in this list in proper sequence (from first to last element).
    <T> T[]
    toArray(T[] a)
    Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface java.util.Collection

    parallelStream, removeIf, stream, toArray

    Methods inherited from interface java.lang.Iterable

    forEach

    Methods inherited from interface java.util.List

    replaceAll, sort, spliterator

  • Field Details

    • factory

      protected Factory<List<E>> factory
      Factory to create the instance of the list to expose.

  • Constructor Details

    • LazyList

      protected LazyList()
      Constructs a new lazy list. Allows factory to be set in subclass constructor.

    • LazyList

      public LazyList(Factory<List<E>> factory)
      Constructs a new lazy list.
      Parameters:
      factory - factory to create the list instance to expose.

  • Method Details

    • size

      public int size()
      Returns the number of elements in this list.
      Specified by:
      size in interface Collection<E>
      Specified by:
      size in interface List<E>

    • isEmpty

      public boolean isEmpty()
      Returns true if this list contains no elements.
      Specified by:
      isEmpty in interface Collection<E>
      Specified by:
      isEmpty in interface List<E>

    • contains

      public boolean contains(Object o)
      Returns true if this list contains the specified element.
      Specified by:
      contains in interface Collection<E>
      Specified by:
      contains in interface List<E>
      Parameters:
      o - the element whose presence in this list is to be tested.
      Returns:
      true if this list contains the specified element.

    • iterator

      public Iterator<E> iterator()
      Returns an iterator over the elements in this list in proper sequence.
      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Iterable<E>
      Specified by:
      iterator in interface List<E>

    • toArray

      public Object[] toArray()
      Returns an array containing all of the elements in this list in proper sequence (from first to last element).
      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>

    • toArray

      public <T> T[] toArray(T[] a)
      Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. If the list fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this list.
      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>
      Parameters:
      a - the array into which the elements of this list are to be stored.
      Returns:
      an array containing the elements of this list.

    • add

      public boolean add(E e)
      Appends the specified element to the end of this list.
      Specified by:
      add in interface Collection<E>
      Specified by:
      add in interface List<E>
      Parameters:
      e - the element to be appended to this list.
      Returns:
      true if this list changed as a result of the call.

    • remove

      public boolean remove(Object o)
      Removes the first occurrence of the specified element from this list, if it is present.
      Specified by:
      remove in interface Collection<E>
      Specified by:
      remove in interface List<E>
      Parameters:
      o - the element to be removed from this list, if present.
      Returns:
      true if this list contained the specified element.

    • containsAll

      public boolean containsAll(Collection<?> c)
      Returns true if this list contains all of the elements of the specified collection.
      Specified by:
      containsAll in interface Collection<E>
      Specified by:
      containsAll in interface List<E>
      Parameters:
      c - the collection to be checked for containment in this list.
      Returns:
      true if this list contains all of the elements of the specified collection.

    • addAll

      public boolean addAll(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.
      Specified by:
      addAll in interface Collection<E>
      Specified by:
      addAll in interface List<E>
      Parameters:
      c - the collection containing elements to be added to this list.
      Returns:
      true if this list changed as a result of the call.

    • addAll

      public boolean addAll(int index, Collection<? extends E> c)
      Inserts all of the elements in the specified collection into this list at the specified position.
      Specified by:
      addAll in interface List<E>
      Parameters:
      index - the index at which to insert the first element from the specified collection.
      c - the collection containing elements to be added to this list.
      Returns:
      true if this list changed as a result of the call.

    • removeAll

      public boolean removeAll(Collection<?> c)
      Removes from this list all of its elements that are contained in the specified collection.
      Specified by:
      removeAll in interface Collection<E>
      Specified by:
      removeAll in interface List<E>
      Parameters:
      c - the collection containing elements to be removed from this list.
      Returns:
      true if this list changed as a result of the call.

    • retainAll

      public boolean retainAll(Collection<?> c)
      Retains only the elements in this list that are contained in the specified collection.
      Specified by:
      retainAll in interface Collection<E>
      Specified by:
      retainAll in interface List<E>
      Parameters:
      c - the collection containing elements to be retained in this list.
      Returns:
      true if this list changed as a result of the call.

    • clear

      public void clear()
      Removes all of the elements from this list.
      Specified by:
      clear in interface Collection<E>
      Specified by:
      clear in interface List<E>

    • equals

      public boolean equals(Object o)
      Compares the specified object with this list for equality.
      Specified by:
      equals in interface Collection<E>
      Specified by:
      equals in interface List<E>
      Overrides:
      equals in class Object
      Parameters:
      o - the object to be compared for equality with this list.
      Returns:
      true if the specified object is equal to this list.

    • hashCode

      public int hashCode()
      Returns the hash code value for this list.
      Specified by:
      hashCode in interface Collection<E>
      Specified by:
      hashCode in interface List<E>
      Overrides:
      hashCode in class Object

    • get

      public E get(int index)
      Returns the element at the specified position in this list.
      Specified by:
      get in interface List<E>
      Parameters:
      index - the index of the element to return.
      Returns:
      the element at the specified position in this list.

    • set

      public E set(int index, E element)
      Replaces the element at the specified position in this list with the specified element.
      Specified by:
      set in interface List<E>
      Parameters:
      index - the index of the element to replace.
      element - the element to be stored at the specified position.
      Returns:
      the element previously at the specified position.

    • add

      public void add(int index, E element)
      Inserts the specified element at the specified position in this list.
      Specified by:
      add in interface List<E>
      Parameters:
      index - the index at which the specified element is to be inserted.
      element - the element to be inserted.

    • remove

      public E remove(int index)
      Removes the element at the specified position in this list.
      Specified by:
      remove in interface List<E>
      Parameters:
      index - the index of the element to be removed.
      Returns:
      the element previously at the specified position.

    • indexOf

      public int indexOf(Object o)
      Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
      Specified by:
      indexOf in interface List<E>
      Parameters:
      o - element to search for.
      Returns:
      the index of the first occurrence, or -1 if no such element.

    • lastIndexOf

      public int lastIndexOf(Object o)
      Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
      Specified by:
      lastIndexOf in interface List<E>
      Parameters:
      o - the element to search for.
      Returns:
      the index of the last occurrence, or -1 if no such element.

    • listIterator

      public ListIterator<E> listIterator()
      Returns a list iterator over the elements in this list (in proper sequence).
      Specified by:
      listIterator in interface List<E>

    • listIterator

      public ListIterator<E> listIterator(int index)
      Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list.
      Specified by:
      listIterator in interface List<E>
      Parameters:
      index - the index of the first element to be returned from the list iterator.
      Returns:
      a list iterator, starting at the specified position in the list.

    • subList

      public List<E> subList(int fromIndex, int toIndex)
      Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
      Specified by:
      subList in interface List<E>
      Parameters:
      fromIndex - low endpoint (inclusive) of the subList.
      toIndex - high endpoint (exclusive) of the subList.
      Returns:
      a view of the specified range within this list.