Return of 'null'

Reports return statements with null return values. While occasionally useful, this construct may make the code more prone to failing with a NullPointerException.

If a method is designed to return null, it is suggested to mark it with the @Nullable annotation - such methods will be ignored by this inspection.

Example:

  class Person {
    public String getName () {
      return null;
    }
  }

After the quick-fix is applied:

  class Person {
    public @Nullable String getName () {
      return null;
    }
  }

If the return type is java.util.Optional, an additional quick-fix to convert null to Optional.empty() is suggested.

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.

ReturnOfNull

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 following options to configure the inspection:

Whether to ignore private methods. This will also ignore return of null from anonymous classes and lambdas.
Whether null values on array returns, collection object returns, plain object returns, or a combination of the three should be reported. Return of null in methods with return type java.util.Optional are always reported.
Click Configure annotations to specify which annotations should be considered 'nullable'.

Inspection options

Here you can find the description of settings available for the Return of 'null' inspection, and the reference of their default values.

Ignore 'private' methods, anonymous classes & lambda's: Not selected
Report methods that return arrays: Default: Selected
Report methods that return collection objects: Default: Selected
Report methods that return objects: Default: Selected

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.2, Qodana for JVM 2024.2,
Can be installed with plugin:	Java, 242.22892

Last modified: 11 September 2024