@NotNull/@Nullable problems

Reports problems related to nullability annotations.

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; }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

NullableProblems

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Use the Configure Annotations button to specify nullability annotations and the checkboxes to fine-tune where the inspection should provide warnings.

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.

Inspection ID: NullableProblems

Inspection options

Here you can find the description of settings available for the @NotNull/@Nullable problems inspection, and the reference of their default values.

Report @NotNull parameters overriding @Nullable and vice versa

Option ID:

REPORT_NOTNULL_PARAMETER_OVERRIDES_NULLABLE

Default value:

Selected

Report non-annotated parameters or methods overriding @NotNull

Option ID:

REPORT_NOT_ANNOTATED_METHOD_OVERRIDES_NOTNULL

Default value:

Selected

Report non-annotated type arguments instantiating non-null type parameter

Option ID:

REPORT_NOT_ANNOTATED_INSTANTIATION_NOT_NULL_TYPE

Default value:

Not selected

Report @NotNull parameters overriding non-annotated

Option ID:

REPORT_NOTNULL_PARAMETERS_OVERRIDES_NOT_ANNOTATED

Default value:

Not selected

Report non-annotated setter parameters or getters of annotated fields

Option ID:

REPORT_NOT_ANNOTATED_GETTER

Default value:

Selected

Report @NotNull parameters with null-literal argument usages

Option ID:

REPORT_NULLS_PASSED_TO_NOT_NULL_PARAMETER

Default value:

Selected

Report nullability annotations on local variables when they are non-applicable

Option ID:

REPORT_NULLABILITY_ANNOTATION_ON_LOCALS

Default value:

Selected

Report assignment of a not null type parameter to nullable type parameter

Option ID:

REPORT_NOT_NULL_TO_NULLABLE_CONFLICTS_IN_ASSIGNMENTS

Default value:

Not selected

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection NullableProblems

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.3

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.3, Qodana for JVM 2025.3,

Last modified: 03 December 2025