```
@Documented
@Retention(RUNTIME)
@Target({TYPE_USE,TYPE_PARAMETER})
@SubtypeOf(MonotonicNonNull.class)
@DefaultQualifierInHierarchy
@QualifierForLiterals(STRING)
@DefaultFor(EXCEPTION_PARAMETER)
@UpperBoundFor(typeKinds={PACKAGE,INT,BOOLEAN,CHAR,DOUBLE,FLOAT,LONG,SHORT,BYTE})
public @interface NonNull
```
If an expression's type is qualified by @NonNull, then the expression never evaluates to null. (Unless the program has a bug; annotations specify intended behavior.)
For fields of a class, the NonNull annotation indicates that this field is never null after the class has been fully initialized. For static fields, the NonNull annotation indicates that this field is never null after the containing class is initialized. "Fully initialized" essentially means that the Java constructor has completed. See the Initialization Checker documentation for more details.
This annotation is rarely written in source code, because it is the default.

See Also:

Nullable, MonotonicNonNull

See the Checker Framework Manual:
Nullness Checker, Initialization Checker, the bottom type

Annotation Type NonNull