ej.bon

Class Immutables

java.lang.Object

ej.bon.Immutables

public class Immutables
extends Object

This class gives access to the global immutable objects pool.

Immutable objects are persistent and normally reside in read-only-memory, such as flash memory.

Immutable objects are created in two ways:

• at runtime by calling put(String, Object) or putAll(Hashtable),
• at system/application configuration time by specifying objects in an XML configuration file.

The method get(String) allows to retrieve an object from the pool using its ID.

Constructor Summary

Constructors

Constructor and Description
Immutables()

Method Summary

Modifier and Type	Method and Description
static String[]	allIDs() Returns an array with the IDs of all the objects in the pool.
static long	freeMemory() Returns the amount of free immutable memory still available.
static Object	get(String ID) Retrieves the object that match the the given ID in the immutable objects pool.
static boolean	isImmutable(Object object) Gets whether or not the given object is in the immutable objects pool or not.
static void	put(String ID, Object object) Maps the given ID to the given object in the immutable objects pool.
static void	putAll(Hashtable table) Maps all the mappings in the given table in the immutable objects pool.
static long	totalMemory() Returns the total amount of immutable memory.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Immutables

public Immutables()

Method Detail

get

public static Object get(String ID)

Retrieves the object that match the the given ID in the immutable objects pool.

If no object can be found with such ID, a NoSuchElementException is thrown.

Parameters:

ID - the ID of the immutable object to get

Returns:

the immutable object matching the ID

Throws:

NoSuchElementException - if the ID is not found

ImmutablesError - if an internal error occurred during immutable access

put

public static void put(String ID,
                       Object object)

Maps the given ID to the given object in the immutable objects pool.

The object can be retrieved by calling the get method with an ID that is equal to the original ID.

Parameters:

ID - the ID of the immutable object to set

object - the object to set immutable

Throws:

NullPointerException - if given object is null

OutOfMemoryError - if the immutable memory is full

See Also:

freeMemory()

putAll

public static void putAll(Hashtable table)

Maps all the mappings in the given table in the immutable objects pool.

Parameters:

table - the table that contains the objects to set immutable

Throws:

NullPointerException - if given table is null

ClassCastException - if an ID is not a String

OutOfMemoryError - if the immutable memory is full

See Also:

freeMemory(), put(String, Object)

isImmutable

public static boolean isImmutable(Object object)

Gets whether or not the given object is in the immutable objects pool or not.

Parameters:

object - the object to check

Returns:

true if the given object is immutable, false otherwise

Throws:

NullPointerException - if given object is null

allIDs

public static String[] allIDs()

Returns an array with the IDs of all the objects in the pool.

Returns:

all the immutable objects ID.

See Also:

get(String)

freeMemory

public static long freeMemory()

Returns the amount of free immutable memory still available.

Returns:

the amount of free immutable memory

totalMemory

public static long totalMemory()

Returns the total amount of immutable memory.

Note that the amount of memory required to hold an object of any given type may be implementation-dependent.

Returns:

the total amount of immutable memory