从实际类中具有相同名称的抽象类中的另一个方法调用方法

Question

I have an abstract class and one class that extend it, I have a method with same name in both class. I want to call the method in abstract class in another method of abstract class.

Controller.java

public abstract class Controller {

    public Result delete(Long id) {
        return this.delete(id, true);
    }
    public Result delete(Long id, boolean useTransaction) {
        // do something and return result
    }
}

FileGroup.java

public class FileGroup extends Controller {

    public Result delete(Long id, boolean central) {
        // do something
        return super.delete(id);
    }
}

super.delete call Controller.delete but this.delete(id, true) call delete in FileGroup instead of calling delete in Controller which is causing recursive infinite loop and stack overflows.

Answer 1

[...] but this.delete(id, true) call delete in FileGroup instead of calling delete in Controller .

Yes, all methods are virtual in Java, and there's no way to avoid that. You can however work around this by creating a (non overridden) helper method in Controller as follows:

public abstract class Controller {

    private Result deleteHelper(Long id, boolean useTransaction) {
        // do something and return result
    }

    public Result delete(Long id) {
        return deleteHelper(id, true);
    }
    public Result delete(Long id, boolean useTransaction) {
        return deleteHelper(id, useTransaction);
    }
}

By doing this you avoid having Controller.delete delegate the call to the subclass.

Answer 2

It's not entirely clear what your question is. If you are just trying to make the method delete in FileGroup call the method delete(id, true) in Controller without causing a stack overflow, you can just do this:

public class FileGroup extends Controller {

    public Result delete(Long id, boolean central) {
        // do something
        return super.delete(id, true);
    }
}

If your question is how to make the one-argument delete method in Controller call the two-argument delete method in Controller rather than the version in FileGroup , the answer is that you should use @aioobe's helper method solution.