lombok

Annotation Type NonNull

@Target(value={FIELD,METHOD,PARAMETER,LOCAL_VARIABLE,TYPE_USE})
 @Retention(value=CLASS)
 @Documented
public @interface NonNull

If put on a parameter, lombok will insert a null-check at the start of the method / constructor's body, throwing a NullPointerException with the parameter's name as message. If put on a field, any generated method assigning a value to this field will also produce these null-checks.