IndirectSet

java.lang.Object
- oracle.toplink.essentials.indirection.IndirectSet

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Iterable, java.util.Collection, java.util.Set, IndirectContainer
```
public class IndirectSet
extends java.lang.Object
implements java.util.Set, IndirectContainer, java.lang.Cloneable, java.io.Serializable
```
IndirectSet is an example implementation of the Set protocol that allows a domain class to take advantage of TopLink Indirection without having to declare its instance variable as a ValueHolderInterface.
To use an IndirectSet:
- Declare the appropriate instance variable with type Set (or Collection).
- Send the message #useTransparentCollection() to the appropriate CollectionMapping.
- Send the message #useCollectionClass(IndirectSet.class) to the same CollectionMapping. (The order of these two message sends is significant.)
TopLink will place an IndirectSet in the instance variable when the containing domain object is read from the datatabase. With the first message sent to the IndirectSet, the contents are fetched from the database and normal Set behavior is resumed.
Implementation notes:
- The Set interface is implemented by delegating nearly every message to the Set held on to by the 'delegate' instance variable. (The 'delegate' will be either a HashSet or yet another IndirectSet.)
- The IndirectContainer interface is implemented in a straightforward fashion:
  - #get- and #setValueHolder() are implemented as simple accessors for the 'valueHolder' instance variable. (Note that #setValueHolder() clears out the 'delegate' instance variable, since its contents are invalidated by the arrival of a new value holder.)
  - #isInstantiated() is simply delegated to the value holder.
- TopLink requires that the Cloneable interface be implemented. The #clone() method must clone the 'delegate'. (The implementation here uses reflection to invoke the #clone() method because it is not included in the common interface shared by IndirectSet and its base delegate class, HashSet; namely, Set.)
- TopLink requires that the Serializable interface be implemented.
- The database read is ultimately triggered when one of the "delegated" methods makes the first call to #getDelegate(), which in turn calls #buildDelegate(), which sends the message #getValue() to the value holder. The value holder performs the database read.
- For debugging purposes, #toString() will not trigger a database read. This is not required behavior.
Since:

TOPLink/Java 3.0+

Author:

Big Country

See Also:

CollectionMapping, Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

protected int initialCapacity
Store initial size for lazy init.

protected float loadFactor
Store load factor for lazy init.

Fields
Modifier and Type	Field and Description
`protected int`	`initialCapacity` Store initial size for lazy init.
`protected float`	`loadFactor` Store load factor for lazy init.

Constructor Summary

Constructors
Constructor and Description
`IndirectSet()` Construct an empty IndirectSet.
`IndirectSet(java.util.Collection c)` Construct an IndirectSet containing the elements of the specified collection.
`IndirectSet(int initialCapacity)` Construct an empty IndirectSet with the specified initial capacity.
`IndirectSet(int initialCapacity, float loadFactor)` Construct an empty IndirectSet with the specified initial capacity and load factor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(java.lang.Object o)`
`boolean`	`addAll(java.util.Collection c)`
`protected java.util.Set`	`buildDelegate()` Return the freshly-built delegate.
`void`	`clear()`
`java.lang.Object`	`clone()`
`protected java.util.Set`	`cloneDelegate()` Clone the delegate.
`boolean`	`contains(java.lang.Object o)`
`boolean`	`containsAll(java.util.Collection c)`
`boolean`	`equals(java.lang.Object o)`
`protected java.util.Set`	`getDelegate()` Check whether the contents have been read from the database.
`java.lang.String`	`getTopLinkAttributeName()` Return the mapping attribute name, used to raise change events.
`ValueHolderInterface`	`getValueHolder()` Return the valueHolder.
`boolean`	`hasBeenRegistered()` INTERNAL: Return whether this IndirectSet has been registered in a UnitOfWork
`int`	`hashCode()`
`boolean`	`isEmpty()`
`boolean`	`isInstantiated()` Return whether the contents have been read from the database.
`java.util.Iterator`	`iterator()`
`protected void`	`raiseAddChangeEvent(java.lang.Object element)` Raise the add change event and relationship maintainence.
`protected void`	`raiseRemoveChangeEvent(java.lang.Object element)` Raise the remove change event.
`boolean`	`remove(java.lang.Object o)`
`boolean`	`removeAll(java.util.Collection c)`
`boolean`	`retainAll(java.util.Collection c)`
`void`	`setTopLinkAttributeName(java.lang.String attributeName)` Set the mapping attribute name, used to raise change events.
`void`	`setValueHolder(ValueHolderInterface valueHolder)` Set the value holder.
`int`	`size()`
`java.lang.Object[]`	`toArray()`
`java.lang.Object[]`	`toArray(java.lang.Object[] a)`
`java.lang.String`	`toString()` Use the delegate's #toString(); but wrap it with braces to indicate there is a bit of indirection.

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

Methods inherited from interface java.util.Set
spliterator

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable
forEach

- Field Detail
  - initialCapacity
```
protected int initialCapacity
```
    Store initial size for lazy init.
  - loadFactor
```
protected float loadFactor
```
    Store load factor for lazy init.
- Constructor Detail
  - IndirectSet
```
public IndirectSet()
```
    Construct an empty IndirectSet.
  - IndirectSet
```
public IndirectSet(int initialCapacity)
```
    Construct an empty IndirectSet with the specified initial capacity.
    
    Parameters:
    
    initialCapacity - the initial capacity of the set
    
    Throws:
    
    java.lang.IllegalArgumentException - if the specified initial capacity is negative
  - IndirectSet
```
public IndirectSet(int initialCapacity,
                   float loadFactor)
```
    Construct an empty IndirectSet with the specified initial capacity and load factor.
    
    Parameters:
    
    initialCapacity - the initial capacity of the set
    
    loadFactor - the load factor of the set
    
    Throws:
    
    java.lang.IllegalArgumentException - if the specified initial capacity is negative
  - IndirectSet
```
public IndirectSet(java.util.Collection c)
```
    Construct an IndirectSet containing the elements of the specified collection.
    
    Parameters:
    
    c - the initial elements of the set
- Method Detail
  - add
```
public boolean add(java.lang.Object o)
```
    Specified by:
    
    add in interface java.util.Collection
    
    Specified by:
    
    add in interface java.util.Set
    
    See Also:
    
    Set.add(java.lang.Object)
  - addAll
```
public boolean addAll(java.util.Collection c)
```
    Specified by:
    
    addAll in interface java.util.Collection
    
    Specified by:
    
    addAll in interface java.util.Set
    
    See Also:
    
    Set.addAll(java.util.Collection)
  - buildDelegate
```
protected java.util.Set buildDelegate()
```
    Return the freshly-built delegate.
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface java.util.Collection
    
    Specified by:
    
    clear in interface java.util.Set
    
    See Also:
    
    Set.clear()
  - clone
```
public java.lang.Object clone()
```
    Overrides:
    
    clone in class java.lang.Object
    
    See Also:
    
    This will result in a database query if necessary.
  - cloneDelegate
```
protected java.util.Set cloneDelegate()
```
    Clone the delegate.
  - contains
```
public boolean contains(java.lang.Object o)
```
    Specified by:
    
    contains in interface java.util.Collection
    
    Specified by:
    
    contains in interface java.util.Set
    
    See Also:
    
    Set.contains(java.lang.Object)
  - containsAll
```
public boolean containsAll(java.util.Collection c)
```
    Specified by:
    
    containsAll in interface java.util.Collection
    
    Specified by:
    
    containsAll in interface java.util.Set
    
    See Also:
    
    Set.containsAll(java.util.Collection)
  - equals
```
public boolean equals(java.lang.Object o)
```
    Specified by:
    
    equals in interface java.util.Collection
    
    Specified by:
    
    equals in interface java.util.Set
    
    Overrides:
    
    equals in class java.lang.Object
    
    See Also:
    
    Set.equals(java.lang.Object)
  - getDelegate
```
protected java.util.Set getDelegate()
```
    Check whether the contents have been read from the database. If they have not, read them and set the delegate.
  - getValueHolder
```
public ValueHolderInterface getValueHolder()
```
    Return the valueHolder.
    
    Specified by:
    
    getValueHolder in interface IndirectContainer
    
    Returns:
    
    oracle.toplink.essentials.indirection.ValueHolderInterface A representation of the valueholder * which this container uses
  - hasBeenRegistered
```
public boolean hasBeenRegistered()
```
    INTERNAL: Return whether this IndirectSet has been registered in a UnitOfWork
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface java.util.Collection
    
    Specified by:
    
    hashCode in interface java.util.Set
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    See Also:
    
    Set.hashCode()
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface java.util.Collection
    
    Specified by:
    
    isEmpty in interface java.util.Set
    
    See Also:
    
    Set.isEmpty()
  - isInstantiated
```
public boolean isInstantiated()
```
    Return whether the contents have been read from the database.
    
    Specified by:
    
    isInstantiated in interface IndirectContainer
  - iterator
```
public java.util.Iterator iterator()
```
    Specified by:
    
    iterator in interface java.lang.Iterable
    
    Specified by:
    
    iterator in interface java.util.Collection
    
    Specified by:
    
    iterator in interface java.util.Set
    
    See Also:
    
    Set.iterator()
  - remove
```
public boolean remove(java.lang.Object o)
```
    Specified by:
    
    remove in interface java.util.Collection
    
    Specified by:
    
    remove in interface java.util.Set
    
    See Also:
    
    Set.remove(java.lang.Object)
  - removeAll
```
public boolean removeAll(java.util.Collection c)
```
    Specified by:
    
    removeAll in interface java.util.Collection
    
    Specified by:
    
    removeAll in interface java.util.Set
    
    See Also:
    
    Set.removeAll(java.util.Collection)
  - retainAll
```
public boolean retainAll(java.util.Collection c)
```
    Specified by:
    
    retainAll in interface java.util.Collection
    
    Specified by:
    
    retainAll in interface java.util.Set
    
    See Also:
    
    Set.retainAll(java.util.Collection)
  - setValueHolder
```
public void setValueHolder(ValueHolderInterface valueHolder)
```
    Set the value holder. Note that the delegate must be cleared out.
    
    Specified by:
    
    setValueHolder in interface IndirectContainer
  - size
```
public int size()
```
    Specified by:
    
    size in interface java.util.Collection
    
    Specified by:
    
    size in interface java.util.Set
    
    See Also:
    
    Set.size()
  - toArray
```
public java.lang.Object[] toArray()
```
    Specified by:
    
    toArray in interface java.util.Collection
    
    Specified by:
    
    toArray in interface java.util.Set
    
    See Also:
    
    Set.toArray()
  - toArray
```
public java.lang.Object[] toArray(java.lang.Object[] a)
```
    Specified by:
    
    toArray in interface java.util.Collection
    
    Specified by:
    
    toArray in interface java.util.Set
    
    See Also:
    
    Set.toArray(java.lang.Object[])
  - toString
```
public java.lang.String toString()
```
    Use the delegate's #toString(); but wrap it with braces to indicate there is a bit of indirection. Don't allow this method to trigger a database read.
    
    Overrides:
    
    toString in class java.lang.Object
    
    See Also:
    
    AbstractCollection.toString()
  - raiseAddChangeEvent
```
protected void raiseAddChangeEvent(java.lang.Object element)
```
    Raise the add change event and relationship maintainence.
  - raiseRemoveChangeEvent
```
protected void raiseRemoveChangeEvent(java.lang.Object element)
```
    Raise the remove change event.
  - getTopLinkAttributeName
```
public java.lang.String getTopLinkAttributeName()
```
    Return the mapping attribute name, used to raise change events.
  - setTopLinkAttributeName
```
public void setTopLinkAttributeName(java.lang.String attributeName)
```
    Set the mapping attribute name, used to raise change events. This is required if the change listener is set.

Class IndirectSet

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Set

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Field Detail

initialCapacity

loadFactor

Constructor Detail

IndirectSet

IndirectSet

IndirectSet

IndirectSet

Method Detail

add

addAll

buildDelegate

clear

clone

cloneDelegate

contains

containsAll

equals

getDelegate

getValueHolder

hasBeenRegistered

hashCode

isEmpty

isInstantiated

iterator

remove

removeAll

retainAll

setValueHolder

size

toArray

toArray

toString

raiseAddChangeEvent

raiseRemoveChangeEvent

getTopLinkAttributeName

setTopLinkAttributeName