Class LinkedList<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<E>
java.util.AbstractSequentialList<E>
java.util.LinkedList<E>
org.datanucleus.store.types.wrappers.LinkedList<E>
org.datanucleus.store.types.wrappers.backed.LinkedList<E>
All Implemented Interfaces:
Serializable, Cloneable, Iterable<E>, Collection<E>, Deque<E>, List<E>, Queue<E>, SCO<LinkedList<E>>, SCOCollection<LinkedList<E>, E>, SCOContainer<LinkedList<E>>, SCOList<LinkedList<E>, E>, BackedSCO
public class LinkedList<E> extends LinkedList<E> implements BackedSCO
A mutable second-class LinkedList object. This class extends LinkedList, using that class to contain the current objects, and the backing ListStore to be the interface to the datastore. A "backing store" is not present for datastores that dont use DatastoreClass, or if the container is serialised or non-persistent.

Modes of Operation

The user can operate the list in 2 modes. The cached mode will use an internal cache of the elements (in the "delegate") reading them at the first opportunity and then using the cache thereafter. The non-cached mode will just go direct to the "backing store" each call.

Mutators

When the "backing store" is present any updates are passed direct to the datastore as well as to the "delegate". If the "backing store" isn't present the changes are made to the "delegate" only.

Accessors

When any accessor method is invoked, it typically checks whether the container has been loaded from its "backing store" (where present) and does this as necessary. Some methods (size()) just check if everything is loaded and use the delegate if possible, otherwise going direct to the datastore.
See Also:

  • Field Details

    • backingStore

      protected transient ListStore<E> backingStore

    • allowNulls

      protected transient boolean allowNulls

    • useCache

      protected transient boolean useCache

    • isCacheLoaded

      protected transient boolean isCacheLoaded

  • Constructor Details

    • LinkedList

      public LinkedList(DNStateManager ownerSM, AbstractMemberMetaData mmd)
      Constructor, using StateManager of the "owner" and the field name.
      Parameters:
      ownerSM - The owner StateManager
      mmd - Metadata for the member

  • Method Details

    • initialise

      public void initialise(LinkedList<E> newValue, Object oldValue)
      Description copied from interface: SCO
      Method to initialise the SCO for use, where replacing an old value with a new value such as when calling a setter field passing in a new value. Note that oldValue is marked as Object since for cases where the member type is Collection the newValue could be, for example, ArrayList, and the oldValue of type Collection (representing null).
      Specified by:
      initialise in interface SCO<E>
      Overrides:
      initialise in class LinkedList<E>
      Parameters:
      newValue - New value (to wrap)
      oldValue - Old value (to use in deciding what needs deleting etc)

    • initialise

      public void initialise(LinkedList<E> c)
      Method to initialise the SCO from an existing value.
      Specified by:
      initialise in interface SCO<E>
      Overrides:
      initialise in class LinkedList<E>
      Parameters:
      c - The object to set from

    • initialise

      public void initialise()
      Method to initialise the SCO for use.
      Specified by:
      initialise in interface SCO<E>
      Overrides:
      initialise in class LinkedList<E>

    • getValue

      public LinkedList<E> getValue()
      Accessor for the unwrapped value that we are wrapping.
      Specified by:
      getValue in interface SCO<E>
      Overrides:
      getValue in class LinkedList<E>
      Returns:
      The unwrapped value

    • load

      public void load()
      Method to effect the load of the data in the SCO. Used when the SCO supports lazy-loading to tell it to load all now.
      Specified by:
      load in interface SCOContainer<E>
      Overrides:
      load in class LinkedList<E>

    • isLoaded

      public boolean isLoaded()
      Method to return if the SCO has its contents loaded. If the SCO doesn't support lazy loading will just return true.
      Specified by:
      isLoaded in interface BackedSCO
      Specified by:
      isLoaded in interface SCOContainer<E>
      Overrides:
      isLoaded in class LinkedList<E>
      Returns:
      Whether it is loaded

    • loadFromStore

      protected void loadFromStore()
      Method to load all elements from the "backing store" where appropriate.

    • getBackingStore

      public Store getBackingStore()
      Specified by:
      getBackingStore in interface BackedSCO

    • updateEmbeddedElement

      public void updateEmbeddedElement(E element, int fieldNumber, Object value, boolean makeDirty)
      Method to update an embedded element in this collection.
      Specified by:
      updateEmbeddedElement in interface SCOCollection<LinkedList<E>, E>
      Overrides:
      updateEmbeddedElement in class LinkedList<E>
      Parameters:
      element - The element
      fieldNumber - Number of field in the element
      value - New value for this field
      makeDirty - Whether to make the SCO field dirty.

    • unsetOwner

      public void unsetOwner()
      Method to unset the owner and field information.
      Specified by:
      unsetOwner in interface SCO<E>
      Overrides:
      unsetOwner in class LinkedList<E>

    • clone

      public Object clone()
      Clone operator to return a copy of this object.

      Mutable second-class Objects are required to provide a public clone method in order to allow for copying persistable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.

      Specified by:
      clone in interface SCO<E>
      Overrides:
      clone in class LinkedList<E>
      Returns:
      The cloned object

    • contains

      public boolean contains(Object element)
      Description copied from class: LinkedList
      Method to return if the list contains this element.
      Specified by:
      contains in interface Collection<E>
      Specified by:
      contains in interface Deque<E>
      Specified by:
      contains in interface List<E>
      Overrides:
      contains in class LinkedList<E>
      Parameters:
      element - The element
      Returns:
      Whether it is contained

    • containsAll

      public boolean containsAll(Collection c)
      Description copied from class: LinkedList
      Accessor for whether a collection of elements are contained here.
      Specified by:
      containsAll in interface Collection<E>
      Specified by:
      containsAll in interface List<E>
      Overrides:
      containsAll in class LinkedList<E>
      Parameters:
      c - The collection of elements.
      Returns:
      Whether they are contained.

    • equals

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

    • forEach

      public void forEach(Consumer<? super E> action)
      Specified by:
      forEach in interface Iterable<E>
      Overrides:
      forEach in class LinkedList<E>

    • get

      public E get(int index)
      Description copied from class: LinkedList
      Method to retrieve an element no.
      Specified by:
      get in interface List<E>
      Overrides:
      get in class LinkedList<E>
      Parameters:
      index - The item to retrieve
      Returns:
      The element at that position.

    • getFirst

      public E getFirst()
      Description copied from class: LinkedList
      Method to retrieve the first element.
      Specified by:
      getFirst in interface Deque<E>
      Overrides:
      getFirst in class LinkedList<E>
      Returns:
      The first element

    • getLast

      public E getLast()
      Description copied from class: LinkedList
      Method to retrieve the last element.
      Specified by:
      getLast in interface Deque<E>
      Overrides:
      getLast in class LinkedList<E>
      Returns:
      The last element

    • hashCode

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

    • indexOf

      public int indexOf(Object element)
      Description copied from class: LinkedList
      Method to the position of an element.
      Specified by:
      indexOf in interface List<E>
      Overrides:
      indexOf in class LinkedList<E>
      Parameters:
      element - The element.
      Returns:
      The position.

    • isEmpty

      public boolean isEmpty()
      Description copied from class: LinkedList
      Accessor for whether the LinkedList is empty.
      Specified by:
      isEmpty in interface Collection<E>
      Specified by:
      isEmpty in interface List<E>
      Overrides:
      isEmpty in class LinkedList<E>
      Returns:
      Whether it is empty.

    • iterator

      public Iterator<E> iterator()
      Description copied from class: LinkedList
      Method to retrieve an iterator for the list.
      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Deque<E>
      Specified by:
      iterator in interface Iterable<E>
      Specified by:
      iterator in interface List<E>
      Overrides:
      iterator in class LinkedList<E>
      Returns:
      The iterator

    • listIterator

      public ListIterator<E> listIterator(int index)
      Description copied from class: LinkedList
      Method to retrieve a List iterator for the list from the index.
      Specified by:
      listIterator in interface List<E>
      Overrides:
      listIterator in class LinkedList<E>
      Parameters:
      index - The start point
      Returns:
      The iterator

    • lastIndexOf

      public int lastIndexOf(Object element)
      Description copied from class: LinkedList
      Method to retrieve the last position of the element.
      Specified by:
      lastIndexOf in interface List<E>
      Overrides:
      lastIndexOf in class LinkedList<E>
      Parameters:
      element - The element
      Returns:
      The last position of this element in the List.

    • size

      public int size()
      Description copied from class: LinkedList
      Accessor for the size of the LinkedList.
      Specified by:
      size in interface Collection<E>
      Specified by:
      size in interface Deque<E>
      Specified by:
      size in interface List<E>
      Overrides:
      size in class LinkedList<E>
      Returns:
      The size.

    • subList

      public List<E> subList(int from, int to)
      Description copied from class: LinkedList
      Accessor for the subList of elements between from and to of the List
      Specified by:
      subList in interface List<E>
      Overrides:
      subList in class LinkedList<E>
      Parameters:
      from - Start index (inclusive)
      to - End index (exclusive)
      Returns:
      The subList

    • toArray

      public Object[] toArray()
      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>
      Overrides:
      toArray in class LinkedList<E>

    • toArray

      public <T> T[] toArray(T[] a)
      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>
      Overrides:
      toArray in class LinkedList<E>

    • add

      public void add(int index, E element)
      Description copied from class: LinkedList
      Method to add an element to a position in the LinkedList.
      Specified by:
      add in interface List<E>
      Overrides:
      add in class LinkedList<E>
      Parameters:
      index - The position
      element - The new element

    • add

      public boolean add(E element)
      Description copied from class: LinkedList
      Method to add an element to the LinkedList.
      Specified by:
      add in interface Collection<E>
      Specified by:
      add in interface Deque<E>
      Specified by:
      add in interface List<E>
      Specified by:
      add in interface Queue<E>
      Overrides:
      add in class LinkedList<E>
      Parameters:
      element - The new element
      Returns:
      Whether it was added ok.

    • addAll

      public boolean addAll(Collection<? extends E> elements)
      Description copied from class: LinkedList
      Method to add a Collection to the LinkedList.
      Specified by:
      addAll in interface Collection<E>
      Specified by:
      addAll in interface List<E>
      Overrides:
      addAll in class LinkedList<E>
      Parameters:
      elements - The collection
      Returns:
      Whether it was added ok.

    • addAll

      public boolean addAll(int index, Collection elements)
      Description copied from class: LinkedList
      Method to add a Collection to a position in the LinkedList.
      Specified by:
      addAll in interface List<E>
      Overrides:
      addAll in class LinkedList<E>
      Parameters:
      index - Position to insert the collection.
      elements - The collection
      Returns:
      Whether it was added ok.

    • addFirst

      public void addFirst(E element)
      Description copied from class: LinkedList
      Method to add an element as first in the LinkedList.
      Specified by:
      addFirst in interface Deque<E>
      Overrides:
      addFirst in class LinkedList<E>
      Parameters:
      element - The new element

    • addLast

      public void addLast(E element)
      Description copied from class: LinkedList
      Method to add an element as last in the LinkedList.
      Specified by:
      addLast in interface Deque<E>
      Overrides:
      addLast in class LinkedList<E>
      Parameters:
      element - The new element

    • clear

      public void clear()
      Description copied from class: LinkedList
      Method to clear the LinkedList.
      Specified by:
      clear in interface Collection<E>
      Specified by:
      clear in interface List<E>
      Overrides:
      clear in class LinkedList<E>

    • remove

      public E remove(int index)
      Description copied from class: LinkedList
      Method to remove an element from the LinkedList.
      Specified by:
      remove in interface List<E>
      Overrides:
      remove in class LinkedList<E>
      Parameters:
      index - The element position.
      Returns:
      The object that was removed

    • remove

      public boolean remove(Object element)
      Description copied from class: LinkedList
      Method to remove (the first occurrence of) an element from the collection
      Specified by:
      remove in interface Collection<E>
      Specified by:
      remove in interface Deque<E>
      Specified by:
      remove in interface List<E>
      Overrides:
      remove in class LinkedList<E>
      Parameters:
      element - The Element to remove
      Returns:
      Whether it was removed successfully.

    • remove

      public boolean remove(Object element, boolean allowCascadeDelete)
      Description copied from class: LinkedList
      Method to remove (the first occurrence of) an element from the collection
      Specified by:
      remove in interface SCOCollection<LinkedList<E>, E>
      Overrides:
      remove in class LinkedList<E>
      Parameters:
      element - The Element to remove
      allowCascadeDelete - Whether to cascade delete
      Returns:
      Whether it was removed successfully.

    • removeAll

      public boolean removeAll(Collection elements)
      Description copied from class: LinkedList
      Method to remove a Collection from the LinkedList.
      Specified by:
      removeAll in interface Collection<E>
      Specified by:
      removeAll in interface List<E>
      Overrides:
      removeAll in class LinkedList<E>
      Parameters:
      elements - The collection
      Returns:
      Whether it was removed ok.

    • removeFirst

      public E removeFirst()
      Description copied from class: LinkedList
      Method to remove the first element from the LinkedList.
      Specified by:
      removeFirst in interface Deque<E>
      Overrides:
      removeFirst in class LinkedList<E>
      Returns:
      The object that was removed

    • removeLast

      public E removeLast()
      Description copied from class: LinkedList
      Method to remove the last element from the LinkedList.
      Specified by:
      removeLast in interface Deque<E>
      Overrides:
      removeLast in class LinkedList<E>
      Returns:
      The object that was removed

    • retainAll

      public boolean retainAll(Collection c)
      Description copied from class: LinkedList
      Method to retain a Collection of elements (and remove all others).
      Specified by:
      retainAll in interface Collection<E>
      Specified by:
      retainAll in interface List<E>
      Overrides:
      retainAll in class LinkedList<E>
      Parameters:
      c - The collection to retain
      Returns:
      Whether they were retained successfully.

    • set

      public E set(int index, E element, boolean allowDependentField)
      Description copied from class: LinkedList
      Wrapper addition that allows turning off of the dependent-field checks when doing the position setting. This means that we can prevent the deletion of the object that was previously in that position. This particular feature is used when attaching a list field and where some elements have changed positions.
      Specified by:
      set in interface SCOList<LinkedList<E>, E>
      Overrides:
      set in class LinkedList<E>
      Parameters:
      index - The position
      element - The new element
      allowDependentField - Whether to allow dependent-field deletes
      Returns:
      The element previously at that position

    • set

      public E set(int index, E element)
      Description copied from class: LinkedList
      Method to set the element at a position in the LinkedList.
      Specified by:
      set in interface List<E>
      Overrides:
      set in class LinkedList<E>
      Parameters:
      index - The position
      element - The new element
      Returns:
      The element previously at that position

    • writeReplace

      protected Object writeReplace() throws ObjectStreamException
      Description copied from class: LinkedList
      The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream. The ObjectOutputStream checks whether the class defines the writeReplace method. If the method is defined, the writeReplace method is called to allow the object to designate its replacement in the stream. The object returned should be either of the same type as the object passed in or an object that when read and resolved will result in an object of a type that is compatible with all references to the object.
      Overrides:
      writeReplace in class LinkedList<E>
      Returns:
      the replaced object
      Throws:
      ObjectStreamException - if an error occurs

    • spliterator

      public Spliterator<E> spliterator()
      Specified by:
      spliterator in interface Collection<E>
      Specified by:
      spliterator in interface Iterable<E>
      Specified by:
      spliterator in interface List<E>
      Overrides:
      spliterator in class LinkedList<E>

    • stream

      public Stream<E> stream()
      Specified by:
      stream in interface Collection<E>
      Overrides:
      stream in class LinkedList<E>

    • parallelStream

      public Stream<E> parallelStream()
      Specified by:
      parallelStream in interface Collection<E>
      Overrides:
      parallelStream in class LinkedList<E>