Package ch.raffael.meldioc

Annotation Interface Provision

@Documented
@Target(METHOD)
@Retention(CLASS)
public @interface Provision

Provisions are components that implement the functionality of the features (Spring beans, Guice bindings, "services"). By default, provisions are unscoped, i.e. a new instance will be created every time the provision is requested. By declaring @Provision(singleton=true), a single, lazily initialized instance will be returned every time the provision is requested. Provision methods cannot be final, as they will be extended in Configurations. They may be abstract, in which case they'll be forwarded to an implementation found in the Configuration.

According to the Java specification, annotations on methods are not inherited. To comply to the constraints set by Java, the annotation must be repeated on all overriding classes. The annotation processor will report an error otherwise. Additionally, if a provision is declared as singleton, this declaration must be repeated in overriding methods, because otherwise, it would fall back to the default, i.e. false. The annotation processor checks that a provision isn't accidentally "downgraded" from singleton to unscoped, it's an error to override a singleton provision with @Provision(singleton=false) or just @Provision. It is possible to "downgrade" a singleton provision to unscoped by additionally specifying the override attribute: @Provision(singleton=false, override=true).

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
boolean	override
boolean	singleton

Element Details

singleton

boolean singleton

Default:

false

override

boolean override

Default:

false