Package org.eclipse.rap.rwt
Class SingletonUtil
- java.lang.Object
-
- org.eclipse.rap.rwt.SingletonUtil
-
public final class SingletonUtil extends java.lang.Object
Creates and maintains a unique instance of a given type for the given scope. The scope is either a UI session or an application context. Within the context of this scope,getUniqueInstance(...)
will always return the same object, but for different scopes the returned instances will be different.This utility class can be used to adjust classic singletons to the appropriate scope in RAP. Example:
public class FooSingleton { private FooSingleton() { } public static FooSingleton getInstance() { return SingletonUtil.getUniqueInstance( FooSingleton.class, RWT.getUISession() ); } }
- Since:
- 2.0
-
-
Constructor Summary
Constructors Constructor Description SingletonUtil()
-
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static <T> T
getSessionInstance(java.lang.Class<T> type)
Returns an instance of the specified type that is unique within the current UI session.static <T> T
getUniqueInstance(java.lang.Class<T> type, ApplicationContext applicationContext)
Returns an instance of the specified type that is unique within the given UI session.static <T> T
getUniqueInstance(java.lang.Class<T> type, UISession uiSession)
Returns an instance of the specified type that is unique within the given UI session.
-
-
-
Method Detail
-
getSessionInstance
public static <T> T getSessionInstance(java.lang.Class<T> type)
Returns an instance of the specified type that is unique within the current UI session. If no such instance exists yet, a new one will be created. The specified type must have a parameterless constructor.This method is a shortcut for
getUniqueInstance( type, RWT.getUISession() )
.- Parameters:
type
- the type to obtain a singleton instance for- Returns:
- the unique instance of the specified type that is associated with the current UI session
-
getUniqueInstance
public static <T> T getUniqueInstance(java.lang.Class<T> type, UISession uiSession)
Returns an instance of the specified type that is unique within the given UI session. If no such instance exists yet, a new one will be created. The specified type must have a parameterless constructor.- Parameters:
type
- the type to obtain a singleton instance foruiSession
- the UI session to store the singleton instance in- Returns:
- the unique instance of the specified type that is associated with the given UI session
- Since:
- 2.3
-
getUniqueInstance
public static <T> T getUniqueInstance(java.lang.Class<T> type, ApplicationContext applicationContext)
Returns an instance of the specified type that is unique within the given UI session. If no such instance exists yet, a new one will be created. The specified type must have a parameterless constructor.- Parameters:
type
- the type to obtain a singleton instance forapplicationContext
- the application context to store the singleton instance in- Returns:
- the unique instance of the specified type that is associated with the given application context
- Since:
- 2.3
-
-