Package checkers.quals

Annotation Interface Unused

@Documented @Retention(RUNTIME) @Target(FIELD) public @interface Unused
Declares that the field may not be accessed if the receiver is of the specified qualifier type (or any supertype). This property is verified by the checker that type-checks the when element value qualifier.

Example Consider a class, Table, with a locking field, lock. The lock is used when a Table instance is shared across threads. When running in a local thread, the lock field ought not to be used. You can declare this behavior in the following way: 


 class Table {
   private @Unused(when=LocalToThread.class) final Lock lock;
   ...
 }
The checker for @LocalToThread would issue an error for the following code: 
  @LocalToThread Table table = ...;
   ... table.lock ...;

  • Required Element Summary

    Required Elements
    Modifier and Type
    Required Element
    Description
    Class<? extends Annotation>
    when
    The field that is annotated with @Unused may not be accessed via a receiver that is annotated with the "when" annotation.

  • Element Details

    • when

      Class<? extends Annotation> when
      The field that is annotated with @Unused may not be accessed via a receiver that is annotated with the "when" annotation.
      Returns:
      the annotation class