Problem with calling super in overridden default method

[Frettman]

This problem is probably easiest to describe using the following standalone code. It's cut down as much as possible from a real world example. Basically I'm trying to extend a class and override a method whose implementation has been provided as default method in an interface somewhere in the hierarchy. Trying to call the overridden method via super fails with Cannot directly invoke the abstract method setReadOnly(boolean) for the type HasValue.

The same code compiles fine with OpenJDK 17.

public class TestField
  extends
    CustomField
{
  @Override
  public void setReadOnly(boolean readOnly)
  {
    // Eclipse shows this compile error: Cannot directly invoke the abstract method setReadOnly(boolean) for the type HasValue
    super.setReadOnly(readOnly);
  }
}

abstract class CustomField
  extends
    AbstractField
  implements
    HasValue
{
}

abstract class AbstractField
  implements
    HasValueAndElement
{
}

interface HasValue
{
  void setReadOnly(boolean readOnly);
}

interface HasValueAndElement
  extends
    HasValue
{
  @Override
  default void setReadOnly(boolean readOnly)
  {
  }
}

[iloveeclipse]

Is this a recent regression? In which version do you see this bug?

[Frettman]

This happened after upgrading the version of a framework. I'm using a fairly recent Eclipse version (4.29), but I just tried and it's the same on 2021-09 (4.21.0). So it's not a recent regression as far as JDT is concerned.

[iloveeclipse]

OK, thanks. I see it also still on latest 4.30 master.
Here the same example just reformatted for clarity

public class TestField extends CustomField {
	@Override
	public void setReadOnly(boolean readOnly) {
		// Eclipse shows this compile error: Cannot directly invoke the abstract
		// method setReadOnly(boolean) for the type HasValue
		super.setReadOnly(readOnly);
	}
}

abstract class CustomField extends AbstractField implements HasValue {}

abstract class AbstractField implements HasValueAndElement {}

interface HasValue {
	void setReadOnly(boolean readOnly);
}

interface HasValueAndElement extends HasValue {
	@Override
	default void setReadOnly(boolean readOnly) {
	}
}

[roeltje25]

I have this issue as well. in 2025-06. In exactly the same framework (Vaadin) and the same code. with javac I can compile it just without issues, in IntelliJ: also no issues. only in eclipse...

[iloveeclipse]

@srikanth-sankaran, could you please check?

[stephan-herrmann]

house keeping: moving to a future milestone.