Annotation Type Optional

  • @Target(METHOD)
    public @interface Optional
    Marks a service contribution method within a module as being optional: it is not an error if the contribution does not match against an actual service. In that case, the method will simply never be invoked. This is occasionally useful when a module is designed to work with another module if the second module is present. Without optional contributions, you would see hard errors when registry is created, and have to create a layer cake of small modules to prevent such errors.
    See Also:
    Contribute, ContributionDef3.isOptional()