Applying this annotation to a declaration has the effect that type references, which are contained in the declaration, and for which a null annotation is otherwise lacking, should be considered as @NonNull.

Locations

This annotation is permitted for these declarations: PACKAGE, TYPE, METHOD, CONSTRUCTOR, FIELD, LOCAL_VARIABLE.

Fine tuning

The exact effect is further controlled by the attribute value, specifying what kinds of locations within the given declaration will be affected. See DefaultLocation for the meaning of the available values.

Nested defaults

If this annotation is applied to a declaration that is already affected by the same annotation at an enclosing scope, the inner annotation replaces the effect of the outer annotation for the scope of the inner declaration.

Canceling a default

In particular, specifying an empty value ({}) for the value attribute has the effect of canceling any null defaults that might be defined for any enclosing scope.

Note that for applying an annotation to a package, a file by the name package-info.java is used.