com.helger.commons.scopes.singleton

Class RequestSingleton

java.lang.Object

com.helger.commons.scopes.AbstractSingleton

com.helger.commons.scopes.singleton.RequestSingleton

All Implemented Interfaces:

IScopeDestructionAware

Direct Known Subclasses:

RequestSingletonTreeWithUniqueID

public abstract class RequestSingleton
extends AbstractSingleton

This is the base class for singleton objects that reside in the request scope. This class can be used for web scopes and non-web scopes as it handled in the same object.

Author:

Philip Helger

See Also:

EScope.REQUEST

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RequestSingleton()

Method Summary

Modifier and Type	Method and Description
static List<RequestSingleton>	getAllRequestSingletons() Get all instantiated singleton objects registered in the current request scope.
static <T extends RequestSingleton> T	getRequestSingleton(Class<T> aClass) Get the singleton object in the current request scope, using the passed class.
static <T extends RequestSingleton> T	getRequestSingletonIfInstantiated(Class<T> aClass) Get the singleton object if it is already instantiated inside the current request scope or null if it is not instantiated.
static boolean	isRequestSingletonInstantiated(Class<? extends RequestSingleton> aClass) Check if a singleton is already instantiated inside the current request scope

Methods inherited from class com.helger.commons.scopes.AbstractSingleton

getAllSingletons, getSingleton, getSingletonIfInstantiated, getSingletonScopeKey, isDestroyed, isInDestruction, isInInstantiation, isInstantiated, isSingletonInstantiated, isUsableObject, onAfterInstantiation, onDestroy, onScopeDestruction, readAbstractSingletonFields, setDestroyed, setInDestruction, setInInstantiation, setInstantiated, toString, writeAbstractSingletonFields

Methods inherited from class java.lang.Object

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

Constructor Detail

RequestSingleton

protected RequestSingleton()

Method Detail

getRequestSingleton

@Nonnull
public static final <T extends RequestSingleton> T getRequestSingleton(@Nonnull
                                                                                 Class<T> aClass)

Get the singleton object in the current request scope, using the passed class. If the singleton is not yet instantiated, a new instance is created.

Parameters:

aClass - The class to be used. May not be null. The class must be public as needs to have a public no-argument constructor.

Returns:

The singleton object and never null.

getRequestSingletonIfInstantiated

@Nullable
public static final <T extends RequestSingleton> T getRequestSingletonIfInstantiated(@Nonnull
                                                                                                Class<T> aClass)

Get the singleton object if it is already instantiated inside the current request scope or null if it is not instantiated.

Parameters:

aClass - The class to be checked. May not be null.

Returns:

The singleton for the specified class is already instantiated, null otherwise.

isRequestSingletonInstantiated

public static final boolean isRequestSingletonInstantiated(@Nonnull
                                                           Class<? extends RequestSingleton> aClass)

Check if a singleton is already instantiated inside the current request scope

Parameters:

aClass - The class to be checked. May not be null.

Returns:

true if the singleton for the specified class is already instantiated, false otherwise.

getAllRequestSingletons

@Nonnull
public static final List<RequestSingleton> getAllRequestSingletons()

Get all instantiated singleton objects registered in the current request scope.

Returns:

A non-null list with all instances of this class in the current request scope.