Abstract class with a single direct inheritor

Reports abstract classes that have precisely one direct inheritor. While such classes may offer admirable clarity of design, in memory-constrained or bandwidth-limited environments, they needlessly increase the total footprint of the application. Consider merging the abstract class with its inheritor.

This inspection is intended for Java ME and other highly resource constrained environments. Applying the results of this inspection without consideration might have negative effects on code clarity and design.

Example:

  abstract class Base {} // will be reported

  class Inheritor extends Base {}

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.

AbstractClassWithOnlyOneDirectInheritor

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.

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.3, Qodana for JVM 2024.3,
Can be installed with plugin:	Java, 243.26483

01 April 2025