Class Stack<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<E>
java.util.Vector<E>
java.util.Stack<E>
org.datanucleus.store.types.wrappers.Stack<E>
org.datanucleus.store.types.wrappers.backed.Stack<E>
All Implemented Interfaces:
Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, RandomAccess, SCO<Stack<E>>, SCOCollection<Stack<E>,E>, SCOContainer<Stack<E>>, SCOList<Stack<E>,E>, BackedSCO
public class Stack<E> extends Stack<E> implements BackedSCO
A mutable second-class Stack object. This class extends Stack, 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

    • Stack

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

  • Method Details

    • initialise

      public void initialise(Stack<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 Stack<E>
      Parameters:
      newValue - New value (to wrap)
      oldValue - Old value (to use in deciding what needs deleting etc)

    • initialise

      public void initialise(Stack<E> c)
      Method to initialise the SCO from an existing value.
      Specified by:
      initialise in interface SCO<E>
      Overrides:
      initialise in class Stack<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 Stack<E>

    • getValue

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

    • contains

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

    • empty

      public boolean empty()
      Description copied from class: Stack
      Accessor for whether the Stack is empty.
      Overrides:
      empty in class Stack<E>
      Returns:
      Whether it is empty.

    • equals

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

    • forEach

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

    • hashCode

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

    • get

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

    • indexOf

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

    • isEmpty

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

    • iterator

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

    • listIterator

      public ListIterator<E> listIterator()
      Description copied from class: Stack
      Method to retrieve a List iterator for the list.
      Specified by:
      listIterator in interface List<E>
      Overrides:
      listIterator in class Stack<E>
      Returns:
      The iterator

    • listIterator

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

    • lastIndexOf

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

    • peek

      public E peek()
      Description copied from class: Stack
      Method to retrieve the element at the top of the stack.
      Overrides:
      peek in class Stack<E>
      Returns:
      The element at the top of the stack

    • size

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

    • subList

      public List<E> subList(int from, int to)
      Description copied from class: Stack
      Accessor for the subList of elements between from and to of the List
      Specified by:
      subList in interface List<E>
      Overrides:
      subList in class Stack<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 Stack<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 Stack<E>

    • add

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

    • add

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

    • addElement

      public void addElement(E element)
      Description copied from class: Stack
      Method to add an element to the Stack
      Overrides:
      addElement in class Stack<E>
      Parameters:
      element - The new element

    • addAll

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

    • addAll

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

    • clear

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

    • pop

      public E pop()
      Description copied from class: Stack
      Method to remove the top element in the stack and return it.
      Overrides:
      pop in class Stack<E>
      Returns:
      The top element that was in the Stack (now removed).

    • push

      public E push(E element)
      Description copied from class: Stack
      Method to push an element onto the stack and return it.
      Overrides:
      push in class Stack<E>
      Parameters:
      element - The element to push onto the stack.
      Returns:
      The element that was pushed onto the Stack

    • remove

      public boolean remove(Object element)
      Description copied from class: Stack
      Method to remove (the first occurrence of) an element from the collection
      Specified by:
      remove in interface Collection<E>
      Specified by:
      remove in interface List<E>
      Overrides:
      remove in class Stack<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: Stack
      Method to remove (the first occurrence of) an element from the collection
      Specified by:
      remove in interface SCOCollection<Stack<E>,E>
      Overrides:
      remove in class Stack<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: Stack
      Method to remove a Collection of objects from the Stack
      Specified by:
      removeAll in interface Collection<E>
      Specified by:
      removeAll in interface List<E>
      Overrides:
      removeAll in class Stack<E>
      Parameters:
      elements - The Collection
      Returns:
      Whether the collection of elements were removed

    • removeElement

      public boolean removeElement(Object element)
      Description copied from class: Stack
      Method to remove an element from the Stack
      Overrides:
      removeElement in class Stack<E>
      Parameters:
      element - The element
      Returns:
      Whether the element was removed

    • remove

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

    • removeElementAt

      public void removeElementAt(int index)
      Description copied from class: Stack
      Method to remove an element from the Stack
      Overrides:
      removeElementAt in class Stack<E>
      Parameters:
      index - The element position.

    • removeAllElements

      public void removeAllElements()
      Description copied from class: Stack
      Method to remove all elements from the Stack. Same as clear().
      Overrides:
      removeAllElements in class Stack<E>

    • retainAll

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

    • setElementAt

      public void setElementAt(E element, int index)
      Description copied from class: Stack
      Method to set the element at a position in the Stack
      Overrides:
      setElementAt in class Stack<E>
      Parameters:
      element - The new element
      index - The position

    • writeReplace

      protected Object writeReplace() throws ObjectStreamException
      Description copied from class: Stack
      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 Stack<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 Stack<E>

    • stream

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

    • parallelStream

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