java-overloading-interfaces.md

Scenario: We have an interface that defines an operation.

public interface Validator {
  Optional validate(String subject, String subject2);
}

Some Validators only have 1 String to validate so we can extend the interface with a simpler one.

public interface SimpleValidator extends Validator {
  
  Optional validate(String subject);
  
  @Override
  default Optional validate(String subject, String subject2) {
    return validate(subject);
  }
}

The above can then be implemented as.

public class SomeSimpleValidator implements SimpleValidator {

  @Override
  public Optional validate(String subject) {
    ...
  }
}