Question

I am now trying to use Preference class using

Preferences pfrOfThis = Preferences.userNodeForPackage(this)

It gets an error:

“method userNodeForPackage in class java.util.prefs.Preferences cannot be applied to given types;
required: java.lang.Class
found: myPac.MainApp
reason: actual argument myPac.MainApp cannot be converted to java.lang.Class by method invocation conversion

Leaking this in constructor”

MainApp here extends JFrame. How comes it is not a Class and could not be used here?

Answer 1

The reference “this” is to an object. Try “this.getClass()”.