@Documented @Retention(RetentionPolicy.SOURCE) @Target(ElementType.TYPE) @GroovyASTTransformationClass("org.codehaus.groovy.transform.SingletonASTTransformation") public @interface Singleton
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:
@Singleton annotation becomes merely documentation)