Public constructor in abstract class

Reports public constructors of abstract classes.

Constructors of abstract classes can only be called from the constructors of their subclasses, declaring them public may be confusing.

The quick-fix makes such constructors protected.

Example:

  public abstract class Foo {
    public Foo () { // warning: has 'public' modifier
        /* ... */
    }
  }

After the quick-fix is applied:

  public abstract class Foo {
    protected Foo () {
        /* ... */
    }
  }

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.

ConstructorNotProtectedInAbstractClass

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.

Settings or Preferences | Editor | Inspections | Java | Inheritance issues

Configure the inspection:

Use the Ignore for non-public classes option below to ignore public constructors in non-public classes.

Inspection ID: NonProtectedConstructorInAbstractClass

Inspection options

Here you can find the description of settings available for the Public constructor in abstract class inspection, and the reference of their default values.

Ignore for non-public classes

Option ID:

m_ignoreNonPublicClasses

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 ConstructorNotProtectedInAbstractClass

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