UsingAnnotations.java

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Inherited
@interface Deletable {
}

@Deletable
class Entity  {
    // implementation details
}

class ShapeDao extends Entity{
    // other dao methods
    boolean delete(Object object) {
        if (!(object instanceof Deletable)) {
            return false;
        }
        // delete implementation details
        return true;
    }
}

public class UsingAnnotations {
    public static void main(String[] args) {
        ShapeDao sd = new ShapeDao();
        System.out.println(sd.delete(sd));
    }
}