Class Abstract class and Interface method precedence

Implementations in classes, including abstract declarations, take precedence over all interface defaults.

Abstract class method takes precedence over Interface Default Method.

public interface Swim {
    default void backStroke() {
        System.out.println("Swim.backStroke");
    }
}

public abstract class AbstractSwimmer implements Swim {
    public void backStroke() {
        System.out.println("AbstractSwimmer.backStroke");
    }
}

public class FooSwimmer extends AbstractSwimmer {
}

The following statement

new FooSwimmer().backStroke();

Will produce

AbstractSwimmer.backStroke

Class method takes precedence over Interface Default Method

public interface Swim {
    default void backStroke() {
        System.out.println("Swim.backStroke");
    }
}

public abstract class AbstractSwimmer implements Swim {
}

public class FooSwimmer extends AbstractSwimmer {
    public void backStroke() {
        System.out.println("FooSwimmer.backStroke");
    }
}

The following statement

new FooSwimmer().backStroke();

Will produce

FooSwimmer.backStroke

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