oracle.toplink.indirection
Class IndirectMap

java.lang.Object
java.util.Dictionary
java.util.Hashtable
oracle.toplink.indirection.IndirectMap

All Implemented Interfaces:

java.lang.Cloneable, IndirectContainer, java.util.Map, java.io.Serializable

public class IndirectMap

extends java.util.Hashtable

implements IndirectContainer

IndirectMap allows a domain class to take advantage of TopLink indirection without having to declare its instance variable as a ValueHolderInterface.

To use an IndirectMap:

• Declare the appropriate instance variable with type Hashtable (jdk1.1) or Map (jdk1.2).
• Send the message #useTransparentMap(String) to the appropriate CollectionMapping.

TopLink will place an IndirectMap in the instance variable when the containing domain object is read from the datatabase. With the first message sent to the IndirectMap, the contents are fetched from the database and normal Hashtable/Map behavior is resumed.

Since:

TOPLink/Java 2.5

See Also:

CollectionMapping, IndirectList, Serialized Form

Constructor Summary

IndirectMap()
PUBLIC: Construct a new, empty IndirectMap with a default capacity and load factor.

IndirectMap(int initialCapacity)
PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and default load factor.

IndirectMap(int initialCapacity, float loadFactor)
PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and load factor.

IndirectMap(java.util.Map m)
PUBLIC: Construct a new IndirectMap with the same mappings as the given Map.

Method Summary

void	clear()
java.lang.Object	clone()
boolean	contains(java.lang.Object value)
boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
java.util.Enumeration	elements()
java.util.Set	entrySet()
boolean	equals(java.lang.Object o)
java.lang.Object	get(java.lang.Object key)
ValueHolderInterface	getValueHolder() PUBLIC: Return the valueHolder.
int	hashCode()
boolean	isEmpty()
boolean	isInstantiated() PUBLIC: Return whether the contents have been read from the database.
java.util.Enumeration	keys()
java.util.Set	keySet()
java.lang.Object	put(java.lang.Object key, java.lang.Object value)
void	putAll(java.util.Map t)
java.lang.Object	remove(java.lang.Object key)
void	setValueHolder(ValueHolderInterface valueHolder) PUBLIC: Set the value holder.
int	size()
java.lang.String	toString() PUBLIC: Use the Hashtable.toString(); but wrap it with braces to indicate there is a bit of indirection.
java.util.Collection	values()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

IndirectMap

public IndirectMap()

PUBLIC: Construct a new, empty IndirectMap with a default capacity and load factor.

IndirectMap

public IndirectMap(int initialCapacity)

PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and default load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable

IndirectMap

public IndirectMap(int initialCapacity,
                   float loadFactor)

PUBLIC: Construct a new, empty IndirectMap with the specified initial capacity and load factor.

Parameters:

initialCapacity - the initial capacity of the hashtable

loadFactor - a number between 0.0 and 1.0

Throws:

java.lang.IllegalArgumentException - if the initial capacity is less than or equal to zero, or if the load factor is less than or equal to zero

IndirectMap

public IndirectMap(java.util.Map m)

PUBLIC: Construct a new IndirectMap with the same mappings as the given Map. The IndirectMap is created with a capacity of twice the number of entries in the given Map or 11 (whichever is greater), and a default load factor, which is 0.75.

Parameters:

m - a map containing the mappings to use

Method Detail

clear

public void clear()

Specified by:

clear in interface java.util.Map

See Also:

Hashtable.clear()

clone

public java.lang.Object clone()

See Also:

This will result in a database query if necessary.

contains

public boolean contains(java.lang.Object value)

See Also:

Hashtable.contains(java.lang.Object)

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map

See Also:

Hashtable.containsKey(java.lang.Object)

containsValue

public boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map

See Also:

Hashtable.containsValue(java.lang.Object)

elements

public java.util.Enumeration elements()

See Also:

Hashtable.elements()

entrySet

public java.util.Set entrySet()

Specified by:

entrySet in interface java.util.Map

See Also:

Hashtable.entrySet()

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map

See Also:

Hashtable.equals(java.lang.Object)

get

public java.lang.Object get(java.lang.Object key)

Specified by:

get in interface java.util.Map

See Also:

Hashtable.get(java.lang.Object)

getValueHolder

public ValueHolderInterface getValueHolder()

PUBLIC: Return the valueHolder.

Specified by:

getValueHolder in interface IndirectContainer

Returns:

oracle.toplink.indirection.ValueHolderInterface A representation of the valueholder * which this container uses

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map

See Also:

Hashtable.hashCode()

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map

See Also:

Hashtable.isEmpty()

isInstantiated

public boolean isInstantiated()

PUBLIC: Return whether the contents have been read from the database.

Specified by:

isInstantiated in interface IndirectContainer

keys

public java.util.Enumeration keys()

See Also:

Hashtable.keys()

keySet

public java.util.Set keySet()

Specified by:

keySet in interface java.util.Map

See Also:

Hashtable.keySet()

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Specified by:

put in interface java.util.Map

See Also:

Hashtable.put(java.lang.Object, java.lang.Object)

putAll

public void putAll(java.util.Map t)

Specified by:

putAll in interface java.util.Map

See Also:

Hashtable.putAll(java.util.Map)

remove

public java.lang.Object remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map

See Also:

Hashtable.remove(java.lang.Object)

setValueHolder

public void setValueHolder(ValueHolderInterface valueHolder)

PUBLIC: Set the value holder.

Specified by:

setValueHolder in interface IndirectContainer

size

public int size()

Specified by:

size in interface java.util.Map

See Also:

Hashtable.size()

toString

public java.lang.String toString()

PUBLIC: Use the Hashtable.toString(); but wrap it with braces to indicate there is a bit of indirection. Don't allow this method to trigger a database read.

See Also:

Hashtable.toString()

values

public java.util.Collection values()

Specified by:

values in interface java.util.Map

See Also:

Hashtable.values()