How can I call getContentResolver in android?

Question

I'm writing a library class to encapsulate some of my logic in my first Android app. One of the functions which I want to encapsulate is a function which queries the address book. As such, it needs a ContentResolver. I'm trying to figure out how to keep the library functions black-boxed... that is, to avoid having each Activity pass in its own context to get a ContentResolver.

Problem is I cannot for the life of me figure out how to get a ContentResolver from within my library function. I can't find an import that contains getContentResolver. Googling said to use getContext to get a Context on which to call getContentResolver, but I can't find an import containing getContext either. Next posts said to use getSystemService to get an object to call getContext. BUT - I can't find any import containing getSystemService either!

So I'm stuck wondering, how can I get a ContentResolver within an encapsulated library function, or am I pretty much stuck having every calling Activity pass in a reference to its own context?

My code is something basically like this:

public final class MyLibrary {
    private MyLibrary() {  }

    // take MyGroupItem as a class representing a projection
    // containing information from the address book groups
    public static ArrayList<MyGroupItem> getGroups() {
        // do work here that would access the contacts
        // thus requiring the ContentResolver
    }
}

getGroups is the method where I was looking to avoid having to pass in a Context or ContentResolver if I could, as I was hoping to have it cleanly black-boxed.

Answer 1

Have each library function call pass in a ContentResolver... Or extend Application to keep hold of a context and access it statically.

Answer 2

You can use like this:

getApplicationContext().getContentResolver() with the proper context.
getActivity().getContentResolver() with the proper context.