Class List<E>

  • All Implemented Interfaces:
    Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, SCO<List<E>>, SCOCollection<List<E>,​E>, SCOContainer<List<E>>, SCOList<List<E>,​E>, BackedSCO

    public class List<E>
    extends List<E>
    implements BackedSCO
    A mutable second-class List object. This class extends AbstractList, 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:
    Serialized Form
    • Field Detail

      • backingStore

        protected transient ListStore<E> backingStore
      • allowNulls

        protected transient boolean allowNulls
      • useCache

        protected transient boolean useCache
      • isCacheLoaded

        protected transient boolean isCacheLoaded
    • Constructor Detail

      • List

        public List​(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 Detail

      • initialise

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

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

        public List getValue()
        Accessor for the unwrapped value that we are wrapping.
        Specified by:
        getValue in interface SCO<E>
        Overrides:
        getValue in class List<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 List<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 List<E>
        Returns:
        Whether it is loaded
      • loadFromStore

        protected void loadFromStore()
        Method to load all elements from the "backing store" where appropriate.
      • 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<List<E>,​E>
        Overrides:
        updateEmbeddedElement in class List<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 List<E>
      • clone

        public Object clone()
        Creates and returns 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 List<E>
        Returns:
        The cloned object
      • contains

        public boolean contains​(Object element)
        Description copied from class: List
        Accessor for whether an element is contained in the List.
        Specified by:
        contains in interface Collection<E>
        Specified by:
        contains in interface List<E>
        Overrides:
        contains in class List<E>
        Parameters:
        element - The element
        Returns:
        Whether the element is contained here
      • containsAll

        public boolean containsAll​(Collection c)
        Description copied from class: List
        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 List<E>
        Parameters:
        c - The collection of elements.
        Returns:
        Whether they are contained.
      • equals

        public boolean equals​(Object o)
        Description copied from class: List
        Equality operator.
        Specified by:
        equals in interface Collection<E>
        Specified by:
        equals in interface List<E>
        Overrides:
        equals in class List<E>
        Parameters:
        o - The object to compare against.
        Returns:
        Whether this object is the same.
      • get

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

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

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

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

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

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

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

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

        public Object[] toArray()
        Description copied from class: List
        Method to return the List as an array.
        Specified by:
        toArray in interface Collection<E>
        Specified by:
        toArray in interface List<E>
        Overrides:
        toArray in class List<E>
        Returns:
        The array
      • toArray

        public Object[] toArray​(Object[] a)
        Description copied from class: List
        Method to return the List as an array.
        Specified by:
        toArray in interface Collection<E>
        Specified by:
        toArray in interface List<E>
        Overrides:
        toArray in class List<E>
        Parameters:
        a - The array to copy to
        Returns:
        The array
      • add

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

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

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

        public boolean addAll​(int index,
                              Collection elements)
        Description copied from class: List
        Method to add a collection of elements.
        Specified by:
        addAll in interface List<E>
        Overrides:
        addAll in class List<E>
        Parameters:
        index - The position to add them
        elements - The collection of elements to add.
        Returns:
        Whether they were added successfully.
      • clear

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

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

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

        public boolean removeAll​(Collection elements)
        Description copied from class: List
        Method to remove a collection of elements from the List.
        Specified by:
        removeAll in interface Collection<E>
        Specified by:
        removeAll in interface List<E>
        Overrides:
        removeAll in class List<E>
        Parameters:
        elements - Collection of elements to remove
        Returns:
        Whether it was successful.
      • retainAll

        public boolean retainAll​(Collection c)
        Description copied from class: List
        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 List<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: List
        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<List<E>,​E>
        Overrides:
        set in class List<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: List
        Method to set the element at a position in the ArrayList.
        Specified by:
        set in interface List<E>
        Overrides:
        set in class List<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: List
        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 List<E>
        Returns:
        the replaced object
        Throws:
        ObjectStreamException - if an error occurs