```
@Retention(RUNTIME)
@Target({FIELD,METHOD,PARAMETER,TYPE_PARAMETER})
public @interface NonNull
```
Indicates that the annotated field or parameter must not be set to null. If validation is active, an exception is thrown when a message is received where a NonNull field has a null or undefined value. In order to achieve consistent behavior, for every field with this annotation the corresponding getter method as well as the parameter of the corresponding setter method are also expected to be annotated.

Annotation Type NonNull