CODEWITHSUNDEEP
javaandroid
Kaloyan Roussev
Kaloyan Roussev

Reputation: 14711

Is there a difference between the way these two usages of a constructor work?

I have an Application class in my Android App, lets call it 

MyApplication.

I have utility classes that I instatiate once in it and then use everywhere in the app

Lets say:

TimeConverter
ImageManager

now, I need to pass those in some asynctask class' constructor

Is there a difference between those two ways of doing so?:

Variant 1:

I pass each of those individually

MyApplication application = (MyApplication) getApplication();

new SomeAsyncTask(application.timeConverter, application.imageManager).execute():


class SomeAsyncTask extends AsyncTask<Void, Void, Void> {

    TimeConverter timeConverter;
    ImageManager imageManager;


    public SomeAsyncTask(TimeConverter timeConverter, ImageManager imageManager) {
        this.timeConverter = timeConverter;
        this.imageManager = imageManager;
    }

    doInBackground...

}

Variant 2:

MyApplication application = (MyApplication) getApplication();

new SomeAsyncTask(application).execute():


class SomeAsyncTask extends AsyncTask<Void, Void, Void> {

    TimeConverter timeConverter;
    ImageManager imageManager;


    public SomeAsyncTask(MyApplication application) {
        this.timeConverter = application.timeConverter;
        this.imageManager = application.imageManager;
    }

    doInBackground...

}

So is there some tangible difference in these two ways of using a constructor from a OOP standpoint (or any other standpoint)

Upvotes: 0

Views: 26

Answers (1)

Manu Zi
Manu Zi

Reputation: 2370

There is not really a different, but the variant 2 is more flexible.

Because if you want to expand the construction, the caller doesn't need to change the method, all new parameters (eg. Stringconverter or something like that) can be in the application object too.

This princip in Java is called value object or DTO (Data Transfer Object) See: http://martinfowler.com/bliki/ValueObject.html

Upvotes: 1

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