@Documented @Retention(RetentionPolicy.SOURCE) @Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.FIELD}) @GroovyASTTransformationClass("org.codehaus.groovy.transform.FinalASTTransformation") public @interface Final
Annotation to add the final modifier to classes, methods, constructors, and fields.
Using `final` and directly using `@Final` will have the same result.
However, the intention is almost never to use `@Final` directly but rather as part
of an annotation collector (meta-annotation).
If you like the behavior of an existing annotation but would really like a version that
also ensured the respective annotated node was final, you can create such an element, e.g.:
@AnnotationCollector
@Canonical
@Final
@interface MyCanonical {}
@MyCanonical class Foo {}
Here, class Foo will be final as well as having all the normal Canonical enhancements.
Similarly, if you wanted to, you could define:
@AnnotationCollector([Singleton, Final]) @interface MySingleton {}
Classes annotated with @MySingleton would be final as well as have all the Singleton enhancements.
As another example, you could define:
@AnnotationCollector([NullCheck, Final, AutoFinal]) @interface MyNullCheck {}
Methods annotated with @MyNullCheck would be final (from @Final),
would have all parameters marked final (from @AutoFinal), and
would have all parameters checked against null (from @NullCheck).
In general, it would be bad style to have an explicit final modifier and a @Final annotation
(or more than one @Final annotation),
but in that scenario if there is an explicit final or at least one enabled @Final,
then the annotated class or member will be final.
| Type | Name and Description |
|---|---|
boolean |
enabledWhen disabled, this annotation effectively becomes a no-op. |
When disabled, this annotation effectively becomes a no-op.
Typically only used to override an annotation collector already containing an enabled @Final annotation.
Care must be taken when disabling final in this way since the annotation collector probably had good reason for enabling final.