Q:

How to initialize context where we cannot get context from getApplicationContext()?

I want to access a class extending SQLiteOpenHelper to get the context of database from a java class. I need to pass application context to get that but don`t have access to getApplicationContext().
How can I get Application Context in java class that is not activity?

A:

I suggest you create a constructor that has a parameter of the Context type. 
public class MySQLiteOpenHelper extends SQLiteOpenHelper {
    // Variables
    private Context ctx;

    public MySQLiteOpenHelper(Context ctx) {
        this.ctx = ctx;
    }

    //More code
}

Now, in your activities, you can do this:
MySQLiteOpenHelper helper = new MySQLiteOpenHelper(this);

And in your fragments, you can do this:
MySQLiteOpenHelper helper = new MySQLiteOpenHelper(getActivity().getApplicationContext()); //getActivity() would work too, Activity (indirectly) extends Context.

