LinkedList (DataNucleus Core 3.2.11 API)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractList<E>
  - - java.util.AbstractSequentialList<E>
    - - java.util.LinkedList
      - org.datanucleus.store.types.simple.LinkedList
        
        org.datanucleus.store.types.backed.LinkedList

All Implemented Interfaces:

Serializable, Cloneable, Iterable, Collection, Deque, List, Queue, BackedSCO, SCO, SCOCollection, SCOContainer, SCOList
```
public class LinkedList
extends LinkedList
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:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`allowNulls`
`protected ListStore`	`backingStore`
`protected boolean`	`isCacheLoaded`
`protected boolean`	`queued`
`protected boolean`	`useCache`

Fields inherited from class org.datanucleus.store.types.simple.LinkedList
delegate, LOCALISER, ownerMmd, ownerOP

Fields inherited from class java.util.AbstractList
modCount

Constructor Summary

Constructors
Constructor and Description

LinkedList(ObjectProvider ownerOP, AbstractMemberMetaData mmd)
Constructor, using the ObjectProvider of the "owner" and the field name.

Constructors
Constructor and Description
`LinkedList(ObjectProvider ownerOP, AbstractMemberMetaData mmd)` Constructor, using the ObjectProvider of the "owner" and the field name.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(int index, Object element)` Method to add an element to a position in the LinkedList.
`boolean`	`add(Object element)` Method to add an element to the LinkedList.
`boolean`	`addAll(Collection elements)` Method to add a Collection to the LinkedList.
`boolean`	`addAll(int index, Collection elements)` Method to add a Collection to a position in the LinkedList.
`void`	`addFirst(Object element)` Method to add an element as first in the LinkedList.
`void`	`addLast(Object element)` Method to add an element as last in the LinkedList.
`void`	`clear()` Method to clear the LinkedList.
`Object`	`clone()` Clone operator to return a copy of this object.
`boolean`	`contains(Object element)` Method to return if the list contains this element.
`boolean`	`containsAll(Collection c)` Accessor for whether a collection of elements are contained here.
`boolean`	`equals(Object o)` Equality operator.
`Object`	`get(int index)` Method to retrieve an element no.
`Store`	`getBackingStore()`
`Object`	`getFirst()` Method to retrieve the first element.
`Object`	`getLast()` Method to retrieve the last element.
`Object`	`getValue()` Accessor for the unwrapped value that we are wrapping.
`int`	`hashCode()` Hashcode operator.
`int`	`indexOf(Object element)` Method to the position of an element.
`void`	`initialise()` Method to initialise the SCO for use.
`void`	`initialise(Object o, boolean forInsert, boolean forUpdate)` Method to initialise the SCO from an existing value.
`boolean`	`isEmpty()` Accessor for whether the LinkedList is empty.
`boolean`	`isLoaded()` Method to return if the SCO has its contents loaded.
`Iterator`	`iterator()` Method to retrieve an iterator for the list.
`int`	`lastIndexOf(Object element)` Method to retrieve the last position of the element.
`ListIterator`	`listIterator(int index)` Method to retrieve a List iterator for the list from the index.
`void`	`load()` Method to effect the load of the data in the SCO.
`protected void`	`loadFromStore()` Method to load all elements from the "backing store" where appropriate.
`Object`	`remove(int index)` Method to remove an element from the LinkedList.
`boolean`	`remove(Object element)` Method to remove an element from the LinkedList.
`boolean`	`remove(Object element, boolean allowCascadeDelete)` Method to remove an element from the collection, and observe the flag for whether to allow cascade delete.
`boolean`	`removeAll(Collection elements)` Method to remove a Collection from the LinkedList.
`Object`	`removeFirst()` Method to remove the first element from the LinkedList.
`Object`	`removeLast()` Method to remove the last element from the LinkedList.
`boolean`	`retainAll(Collection c)` Method to retain a Collection of elements (and remove all others).
`Object`	`set(int index, Object element)` Method to set the element at a position in the LinkedList.
`Object`	`set(int index, Object element, boolean allowDependentField)` Wrapper addition that allows turning off of the dependent-field checks when doing the position setting.
`int`	`size()` Accessor for the size of the LinkedList.
`List`	`subList(int from, int to)` Accessor for the subList of elements between from and to of the List
`Object[]`	`toArray()` Method to return the list as an array.
`Object[]`	`toArray(Object[] a)` Method to return the list as an array.
`void`	`unsetOwner()` Method to unset the owner and field information.
`void`	`updateEmbeddedElement(Object element, int fieldNumber, Object value)` Method to update an embedded element in this collection.
`protected Object`	`writeReplace()` The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream.

Methods inherited from class org.datanucleus.store.types.simple.LinkedList
attachCopy, detachCopy, getFieldName, getOwner, makeDirty

Methods inherited from class java.util.LinkedList
descendingIterator, element, offer, offerFirst, offerLast, peek, peekFirst, peekLast, poll, pollFirst, pollLast, pop, push, remove, removeFirstOccurrence, removeLastOccurrence

Methods inherited from class java.util.AbstractList
listIterator, removeRange

Methods inherited from class java.util.AbstractCollection
toString

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List
listIterator

- Field Detail
  - backingStore
```
protected transient ListStore backingStore
```
  - allowNulls
```
protected transient boolean allowNulls
```
  - useCache
```
protected transient boolean useCache
```
  - isCacheLoaded
```
protected transient boolean isCacheLoaded
```
  - queued
```
protected transient boolean queued
```
- Constructor Detail
  - LinkedList
```
public LinkedList(ObjectProvider ownerOP,
          AbstractMemberMetaData mmd)
```
    Constructor, using the ObjectProvider of the "owner" and the field name.
    
    Parameters:
    ownerOP - The owner ObjectProvider
    mmd - Metadata for the member
- Method Detail
  - initialise
```
public void initialise(Object o,
              boolean forInsert,
              boolean forUpdate)
```
    Method to initialise the SCO from an existing value.
    
    Specified by:
    
    initialise in interface SCO
    
    Overrides:
    
    initialise in class LinkedList
    
    Parameters:
    o - The object to set from
    forInsert - Whether the object needs inserting in the datastore with this value
    forUpdate - Whether to update the datastore with this value
  - initialise
```
public void initialise()
```
    Method to initialise the SCO for use.
    
    Specified by:
    
    initialise in interface SCO
    
    Overrides:
    
    initialise in class LinkedList
  - getValue
```
public Object getValue()
```
    Accessor for the unwrapped value that we are wrapping.
    
    Specified by:
    
    getValue in interface SCO
    
    Overrides:
    
    getValue in class LinkedList
    
    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
    
    Overrides:
    
    load in class LinkedList
  - 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 SCOContainer
    
    Overrides:
    
    isLoaded in class LinkedList
    
    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(Object element,
                         int fieldNumber,
                         Object value)
```
    Method to update an embedded element in this collection.
    
    Specified by:
    
    updateEmbeddedElement in interface SCOCollection
    
    Overrides:
    
    updateEmbeddedElement in class LinkedList
    
    Parameters:
    element - The element
    fieldNumber - Number of field in the element
    value - New value for this field
  - unsetOwner
```
public void unsetOwner()
```
    Method to unset the owner and field information.
    
    Specified by:
    
    unsetOwner in interface SCO
    
    Overrides:
    
    unsetOwner in class LinkedList
  - 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 PersistenceCapable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.
    
    Specified by:
    
    clone in interface SCO
    
    Overrides:
    
    clone in class LinkedList
    
    Returns:
    The cloned object
  - contains
```
public boolean contains(Object element)
```
    Method to return if the list contains this element.
    
    Specified by:
    
    contains in interface Collection
    
    Specified by:
    
    contains in interface Deque
    
    Specified by:
    
    contains in interface List
    
    Overrides:
    
    contains in class LinkedList
    
    Parameters:
    element - The element
    
    Returns:
    Whether it is contained
  - containsAll
```
public boolean containsAll(Collection c)
```
    Accessor for whether a collection of elements are contained here.
    
    Specified by:
    
    containsAll in interface Collection
    
    Specified by:
    
    containsAll in interface List
    
    Overrides:
    
    containsAll in class LinkedList
    
    Parameters:
    c - The collection of elements.
    
    Returns:
    Whether they are contained.
  - equals
```
public boolean equals(Object o)
```
    Equality operator.
    
    Specified by:
    
    equals in interface Collection
    
    Specified by:
    
    equals in interface List
    
    Overrides:
    
    equals in class LinkedList
    
    Parameters:
    o - The object to compare against.
    
    Returns:
    Whether this object is the same.
  - get
```
public Object get(int index)
```
    Method to retrieve an element no.
    
    Specified by:
    
    get in interface List
    
    Overrides:
    
    get in class LinkedList
    
    Parameters:
    index - The item to retrieve
    
    Returns:
    The element at that position.
  - getFirst
```
public Object getFirst()
```
    Method to retrieve the first element.
    
    Specified by:
    
    getFirst in interface Deque
    
    Overrides:
    
    getFirst in class LinkedList
    
    Returns:
    The first element
  - getLast
```
public Object getLast()
```
    Method to retrieve the last element.
    
    Specified by:
    
    getLast in interface Deque
    
    Overrides:
    
    getLast in class LinkedList
    
    Returns:
    The last element
  - hashCode
```
public int hashCode()
```
    Hashcode operator.
    
    Specified by:
    
    hashCode in interface Collection
    
    Specified by:
    
    hashCode in interface List
    
    Overrides:
    
    hashCode in class LinkedList
    
    Returns:
    The Hash code.
  - indexOf
```
public int indexOf(Object element)
```
    Method to the position of an element.
    
    Specified by:
    
    indexOf in interface List
    
    Overrides:
    
    indexOf in class LinkedList
    
    Parameters:
    element - The element.
    
    Returns:
    The position.
  - isEmpty
```
public boolean isEmpty()
```
    Accessor for whether the LinkedList is empty.
    
    Specified by:
    
    isEmpty in interface Collection
    
    Specified by:
    
    isEmpty in interface List
    
    Overrides:
    
    isEmpty in class LinkedList
    
    Returns:
    Whether it is empty.
  - iterator
```
public Iterator iterator()
```
    Method to retrieve an iterator for the list.
    
    Specified by:
    
    iterator in interface Iterable
    
    Specified by:
    
    iterator in interface Collection
    
    Specified by:
    
    iterator in interface Deque
    
    Specified by:
    
    iterator in interface List
    
    Overrides:
    
    iterator in class LinkedList
    
    Returns:
    The iterator
  - listIterator
```
public ListIterator listIterator(int index)
```
    Method to retrieve a List iterator for the list from the index.
    
    Specified by:
    
    listIterator in interface List
    
    Overrides:
    
    listIterator in class LinkedList
    
    Parameters:
    index - The start point
    
    Returns:
    The iterator
  - lastIndexOf
```
public int lastIndexOf(Object element)
```
    Method to retrieve the last position of the element.
    
    Specified by:
    
    lastIndexOf in interface List
    
    Overrides:
    
    lastIndexOf in class LinkedList
    
    Parameters:
    element - The element
    
    Returns:
    The last position of this element in the List.
  - size
```
public int size()
```
    Accessor for the size of the LinkedList.
    
    Specified by:
    
    size in interface Collection
    
    Specified by:
    
    size in interface Deque
    
    Specified by:
    
    size in interface List
    
    Overrides:
    
    size in class LinkedList
    
    Returns:
    The size.
  - subList
```
public List subList(int from,
           int to)
```
    Accessor for the subList of elements between from and to of the List
    
    Specified by:
    
    subList in interface List
    
    Overrides:
    
    subList in class LinkedList
    
    Parameters:
    from - Start index (inclusive)
    to - End index (exclusive)
    
    Returns:
    The subList
  - toArray
```
public Object[] toArray()
```
    Method to return the list as an array.
    
    Specified by:
    
    toArray in interface Collection
    
    Specified by:
    
    toArray in interface List
    
    Overrides:
    
    toArray in class LinkedList
    
    Returns:
    The array
  - toArray
```
public Object[] toArray(Object[] a)
```
    Method to return the list as an array.
    
    Specified by:
    
    toArray in interface Collection
    
    Specified by:
    
    toArray in interface List
    
    Overrides:
    
    toArray in class LinkedList
    
    Parameters:
    a - The runtime types of the array being defined by this param
    
    Returns:
    The array
  - add
```
public void add(int index,
       Object element)
```
    Method to add an element to a position in the LinkedList.
    
    Specified by:
    
    add in interface List
    
    Overrides:
    
    add in class LinkedList
    
    Parameters:
    index - The position
    element - The new element
  - add
```
public boolean add(Object element)
```
    Method to add an element to the LinkedList.
    
    Specified by:
    
    add in interface Collection
    
    Specified by:
    
    add in interface Deque
    
    Specified by:
    
    add in interface List
    
    Specified by:
    
    add in interface Queue
    
    Overrides:
    
    add in class LinkedList
    
    Parameters:
    element - The new element
    
    Returns:
    Whether it was added ok.
  - addAll
```
public boolean addAll(Collection elements)
```
    Method to add a Collection to the LinkedList.
    
    Specified by:
    
    addAll in interface Collection
    
    Specified by:
    
    addAll in interface List
    
    Overrides:
    
    addAll in class LinkedList
    
    Parameters:
    elements - The collection
    
    Returns:
    Whether it was added ok.
  - addAll
```
public boolean addAll(int index,
             Collection elements)
```
    Method to add a Collection to a position in the LinkedList.
    
    Specified by:
    
    addAll in interface List
    
    Overrides:
    
    addAll in class LinkedList
    
    Parameters:
    index - Position to insert the collection.
    elements - The collection
    
    Returns:
    Whether it was added ok.
  - addFirst
```
public void addFirst(Object element)
```
    Method to add an element as first in the LinkedList.
    
    Specified by:
    
    addFirst in interface Deque
    
    Overrides:
    
    addFirst in class LinkedList
    
    Parameters:
    element - The new element
  - addLast
```
public void addLast(Object element)
```
    Method to add an element as last in the LinkedList.
    
    Specified by:
    
    addLast in interface Deque
    
    Overrides:
    
    addLast in class LinkedList
    
    Parameters:
    element - The new element
  - clear
```
public void clear()
```
    Method to clear the LinkedList.
    
    Specified by:
    
    clear in interface Collection
    
    Specified by:
    
    clear in interface List
    
    Overrides:
    
    clear in class LinkedList
  - remove
```
public Object remove(int index)
```
    Method to remove an element from the LinkedList.
    
    Specified by:
    
    remove in interface List
    
    Overrides:
    
    remove in class LinkedList
    
    Parameters:
    index - The element position.
    
    Returns:
    The object that was removed
  - remove
```
public boolean remove(Object element)
```
    Method to remove an element from the LinkedList.
    
    Specified by:
    
    remove in interface Collection
    
    Specified by:
    
    remove in interface Deque
    
    Specified by:
    
    remove in interface List
    
    Overrides:
    
    remove in class LinkedList
    
    Parameters:
    element - The element
    
    Returns:
    Whether the object was removed ok
  - remove
```
public boolean remove(Object element,
             boolean allowCascadeDelete)
```
    Method to remove an element from the collection, and observe the flag for whether to allow cascade delete.
    
    Specified by:
    
    remove in interface SCOCollection
    
    Overrides:
    
    remove in class LinkedList
    
    Parameters:
    element - The element
    allowCascadeDelete - Whether to allow cascade delete
    
    Returns:
    Whether it was removed successfully.
  - removeAll
```
public boolean removeAll(Collection elements)
```
    Method to remove a Collection from the LinkedList.
    
    Specified by:
    
    removeAll in interface Collection
    
    Specified by:
    
    removeAll in interface List
    
    Overrides:
    
    removeAll in class LinkedList
    
    Parameters:
    elements - The collection
    
    Returns:
    Whether it was removed ok.
  - removeFirst
```
public Object removeFirst()
```
    Method to remove the first element from the LinkedList.
    
    Specified by:
    
    removeFirst in interface Deque
    
    Overrides:
    
    removeFirst in class LinkedList
    
    Returns:
    The object that was removed
  - removeLast
```
public Object removeLast()
```
    Method to remove the last element from the LinkedList.
    
    Specified by:
    
    removeLast in interface Deque
    
    Overrides:
    
    removeLast in class LinkedList
    
    Returns:
    The object that was removed
  - retainAll
```
public boolean retainAll(Collection c)
```
    Method to retain a Collection of elements (and remove all others).
    
    Specified by:
    
    retainAll in interface Collection
    
    Specified by:
    
    retainAll in interface List
    
    Overrides:
    
    retainAll in class LinkedList
    
    Parameters:
    c - The collection to retain
    
    Returns:
    Whether they were retained successfully.
  - set
```
public Object set(int index,
         Object element,
         boolean allowDependentField)
```
    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
    
    Overrides:
    
    set in class LinkedList
    
    Parameters:
    index - The position
    element - The new element
    allowDependentField - Whether to allow dependent-field deletes
    
    Returns:
    The element previously at that position
  - set
```
public Object set(int index,
         Object element)
```
    Method to set the element at a position in the LinkedList.
    
    Specified by:
    
    set in interface List
    
    Overrides:
    
    set in class LinkedList
    
    Parameters:
    index - The position
    element - The new element
    
    Returns:
    The element previously at that position
  - writeReplace
```
protected Object writeReplace()
                       throws ObjectStreamException
```
    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
    
    Returns:
    the replaced object
    
    Throws:
    
    ObjectStreamException

Class LinkedList

Modes of Operation

Mutators

Accessors

Field Summary

Fields inherited from class org.datanucleus.store.types.simple.LinkedList

Fields inherited from class java.util.AbstractList

Constructor Summary

Method Summary

Methods inherited from class org.datanucleus.store.types.simple.LinkedList

Methods inherited from class java.util.LinkedList

Methods inherited from class java.util.AbstractList

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.List

Field Detail

backingStore

allowNulls

useCache

isCacheLoaded

queued

Constructor Detail

LinkedList

Method Detail

initialise

initialise

getValue

load

isLoaded

loadFromStore

getBackingStore

updateEmbeddedElement

unsetOwner

clone

contains

containsAll

equals

get

getFirst

getLast

hashCode

indexOf

isEmpty

iterator

listIterator

lastIndexOf

size

subList

toArray

toArray

add

add

addAll

addAll

addFirst

addLast

clear

remove

remove

remove

removeAll

removeFirst

removeLast

retainAll

set

set

writeReplace