Covariant 'equals()'

Reports equals() methods taking an argument type other than java.lang.Object if the containing class does not have other overloads of equals() that take java.lang.Object as its argument type.

A covariant version of equals() does not override the Object.equals(Object) method. It may cause unexpected behavior at runtime. For example, if the class is used to construct one of the standard collection classes, which expect that the Object.equals(Object) method is overridden.

Example:

  class Foo {
      public boolean equals(Foo foo) {  // warning
          return false;
      }
  }
  class Bar {
      public boolean equals(Bar bar) {  // no warning here
          return false;
      }
      @Override
      public boolean equals(Object obj) {
          return false;
      }
  }

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.

CovariantEquals

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