Question

I need to use some methods from a helper class but having trouble when I try to create a object of the helper class in my activity.

HelperClass helper = new HelperClass();

When I do the above I get an error saying I need to make the visibility of Helper() default.
Here is the relevant part of the helper class.

public class HelperClass {

private static HelperClass helperClass;
private String list;

private HelperClass() {
    initialiseHelper();
}

When I take out the private in the HelperClass it is fine but I do not want to edit this class. Is there a way around this?

Answer 1

It looks like you’re trying to apply Singleton pattern, but you’re missing the getInstance() method, which should look like this:

public static synchronized HelperClass getInstance() {
    if (helperClass == null) {
        helperClass = new HelperClass();
    }
    return helperClass;
}

Now you should use this method everywhere you want to reference an instance of HelperClass. Hope this helps.