-
Class annotation to make a singleton class. The singleton is obtained through normal property access using the singleton property (defaults to "instance").
Such classes can be initialized during normal static initialization of the class or lazily (on first access).
To make the singleton lazy use @Singleton(lazy=true)
.
Lazy singletons are implemented with double-checked locking and a volatile backing field.
By default, no explicit constructors are allowed. To create one or more explicit constructors
use @Singleton(strict=false)
.
This could be used to:
- provide your own custom initialization logic in your own no-arg constructor - you
will be responsible for the entire code (the
@Singleton
annotation becomes merely documentation)
- provide one or more constructors with arguments for a quasi-singleton - these constructors will be used
to create instances that are independent of the singleton instance returned by the singleton property
- Authors:
- Alex Tkachman
- Paul King
-
-
Element Summary
Optional Element Summary
Type |
Name and Description |
boolean |
lazy
@default false- Returns:
- if this singleton should be lazy
|
String |
property
@default "instance"- Returns:
- the singleton property name
|
boolean |
strict
@default true- Returns:
- if this singleton should have strict semantics
|
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Inherited Methods Summary
-
-
Element Detail
-
public boolean lazy
@default false
- Returns:
- if this singleton should be lazy
-
public String property
@default "instance"
- Returns:
- the singleton property name
-
public boolean strict
@default true
- Returns:
- if this singleton should have strict semantics
Copyright © 2003-2018 The Apache Software Foundation. All rights reserved.