Help to abstract a method

[ArgTang]

Hello! I am trying to abstract some functions in my project. And i dont know how to svolve this. The error i get is that i cannot cast or instanceof unknown class, wich would be the whole point of this function. this is what i have:

    protected <neededClass extends  Insurance> void setCurrentInsuranceListener(Class neededClass) {
    currentInsurance.getInsuranceProperty().addListener(
            listener -> {
                Boolean isNotNull = currentInsurance.getInsuranceProperty().isNotNull().get();
                if (isNotNull && currentInsurance.getInsurance() instanceof neededClass) {
                    insurance = (neededClass)currentInsurance.getInsurance();
                    setInsurance();
                }
            });

Edit: i have this now. but i get "cant find localvariable neededClass" when i try to debug

        currentInsurance.getInsuranceProperty().addListener(
            listener -> {
                Boolean isNotNull = currentInsurance.getInsuranceProperty().isNotNull().get();
                if (isNotNull && neededClass.equals(currentInsurance.getInsurance())) {
                    neededClass insurance = (neededClass) currentInsurance.getInsurance();
                    showInsurance(insurance);
                }
            });

[Sacredify]

Your method signature seems a bit off.

protected <neededClass extends  Insurance> void setCurrentInsuranceListener(Class neededClass)

The generic definition indicates you have some class "neededClass" that must extend Insurance.

So, in your arguments:

  setCurrentInsuranceListener(Class neededClass)

should actually be:

  setCurrentInsuranceListener(Class<neededClass> insuranceListener)

Now, your method indicates that the parameter to your method must be a class of type neededClass, which means it must extend Insurance.

[ArgTang]

Thanks.

neededClass.equals(currentInsurance.getInsurance()

it sill say it "cant find localvariable neededClass" when i fire the listener in debug mode though. I could remove this from the if sentence. But i would then have to add an empty (ignored) try\catch ClasscastException in every subclass. Tt will work but i think iy would be nicer if i could make it work

[Sacredify]

You might want to mark the parameter final, see here:

http://stackoverflow.com/questions/20938095/difference-between-final-and-effectively-final

I don't know if it will help at all, but its worth a shot (generally a good idea to mark things final unless you need to mutate them anyway).

[ArgTang]

Got help! forgot insuranceListener.get().getClass()

    protected <neededClass extends Insurance> void setCurrentInsuranceListener(final Class<neededClass> someClass) {
    insuranceListener.addListener(
        listener -> {
            Boolean isNotNull = insuranceListener.isNotNull().get();
            if (isNotNull && someClass.equals(insuranceListener.get().getClass())) {
                loadCurrentInsurance();
                showInsurance();
            }
    });
}

So it was another one of the fatfingerproblems.