Cast to incompatible type

Reports type cast expressions where the casted expression has a class/interface type that neither extends/implements the cast class/interface type, nor has subclasses that do.

Such a construct is likely erroneous, and will throw a java.lang.ClassCastException at runtime.

Example:

  interface A {}
  interface Z {}
  static class C {}

  void x(C c) {
    if (c instanceof Z) {
      A a = ((A)c); // cast to incompatible interface 'A'
    }
  }

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.

CastToIncompatibleInterface

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 | Probable bugs

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