'equals()' method that does not check the class of its parameter

Reports equals() methods that do not check the type of their parameter.

Failure to check the type of the parameter in the equals() method may result in latent errors if the object is used in an untyped collection.

Example:

  class MyClass {
    int x;

    @Override
    public boolean equals(Object obj) {
      // equals method should return false if obj is not MyClass
      return ((MyClass)obj).x == x;
    }
  }

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.

EqualsWhichDoesntCheckParameterClass

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

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 EqualsWhichDoesntCheckParameterClass

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025