Examples:

• Overriding methods are not annotated:

  
  abstract class A {
    @NotNull abstract String m();
  }
  class B extends A {
      String m() { return "empty string"; }
  }
      

• Annotated primitive types: @NotNull int myFoo;
• Both @Nullable and @NotNull are present on the same member: @Nullable @NotNull String myFooString;
• Collection of nullable elements is assigned into a collection of non-null elements:

  
  void testList(List<@Nullable String> nullableList) {
     List<@NotNull String> list2 = nullableList;
  }
      

Use the Configure Annotations button to specify nullability annotations. The options are grouped into three sections — overriding methods and parameters, generic types, and declarations and annotations — to fine-tune where the inspection should provide warnings. Each option has a ? icon that explains what it reports.

This inspection only reports if the language level of the project or module is 5 or higher, and nullability annotations are available on the classpath.