Class UnmodifiableArrayList<E>

Object
AbstractCollection<E>
AbstractList<E>
UnmodifiableArrayList<E>
Type Parameters:
E - The type of elements in the list.
All Implemented Interfaces:
Serializable, Iterable<E>, Collection<E>, List<E>, CheckedCollection<E>

public class UnmodifiableArrayList<E> extends AbstractList<E> implements CheckedCollection<E>, Serializable
An unmodifiable view of an array. Invoking
UnmodifiableArrayList.wrap(array);
is equivalent to
Collections.unmodifiableList(Arrays.asList(array)));
But this class provides a very slight performance improvement since it uses one less level of indirection.
Since:
2.1
Author:
Martin Desruisseaux (IRD)
See Also:
  • Constructor Details

    • UnmodifiableArrayList

      @SafeVarargs protected UnmodifiableArrayList(E... array)
      Creates a new instance of an array list. A direct reference to the given array is retained (i.e. the array is not cloned). Consequently the given array should not be modified after construction if this list is intented to be immutable.

      This constructor is for subclassing only. Users should invoke the wrap(E...) static factory method, which provides more convenient handling of parameterized types.

      Parameters:
      array - The array to wrap.
  • Method Details

    • wrap

      @SafeVarargs public static <E> UnmodifiableArrayList<E> wrap(E... array)
      Creates a new instance of an array list. A direct reference to the given array is retained (i.e. the array is not cloned). Consequently the given array should not be modified after construction if this list is intented to be immutable.
      Type Parameters:
      E - The type of elements in the list.
      Parameters:
      array - The array to wrap.
      Returns:
      The given array wrapped in an unmodifiable list.
      Since:
      2.5
    • getElementType

      public Class<E> getElementType()
      Returns the element type of the wrapped array.
      Specified by:
      getElementType in interface CheckedCollection<E>
      Returns:
      The type of elements in the list.
    • size

      public int size()
      Returns the list size.
      Specified by:
      size in interface Collection<E>
      Specified by:
      size in interface List<E>
      Specified by:
      size in class AbstractCollection<E>
    • get

      public E get(int index)
      Returns the element at the specified index.
      Specified by:
      get in interface List<E>
      Specified by:
      get in class AbstractList<E>
    • indexOf

      public int indexOf(Object object)
      Returns the index in this list of the first occurence of the specified element, or -1 if the list does not contain this element. This method is overridden only for performance reason (the default implementation would work as well).
      Specified by:
      indexOf in interface List<E>
      Overrides:
      indexOf in class AbstractList<E>
      Parameters:
      object - The element to search for.
    • lastIndexOf

      public int lastIndexOf(Object object)
      Returns the index in this list of the last occurence of the specified element, or -1 if the list does not contain this element. This method is overridden only for performance reason (the default implementation would work as well).
      Specified by:
      lastIndexOf in interface List<E>
      Overrides:
      lastIndexOf in class AbstractList<E>
      Parameters:
      object - The element to searcch for.
    • contains

      public boolean contains(Object object)
      Returns true if this collection contains the specified element. This method is overridden only for performance reason (the default implementation would work as well).
      Specified by:
      contains in interface Collection<E>
      Specified by:
      contains in interface List<E>
      Overrides:
      contains in class AbstractCollection<E>
      Parameters:
      object - The element to check for existence.