Junit: Calling private method without instance

Question

There are no Junits are written in application. But in other module we have started writing Junits using Jmockit. So any core java or Jmockit solution will be highly appreciated.

I have application initialization class, which is singleton, it initialize application by calling database[data load], property file etc. Its object creation is complex.

I am writing new method to initialize class [method name addMoreInitilization].

I want to write Junit for above scenario. Is there way to write Junit for addMoreInitilization method without calling complex object creation logic because it have lot of dependencies and mocking them all is not feasible and also do not want to make method static ?

Pseudo java code for ApplicationStartUp class below

Class ApplicationStartUp {

   private ApplicationStartUp applicationStartUp;
   // assume single ton implemented

   private ApplicationStartUp () {
       // complex object creation
       addMoreInitilization();
   }

    public static getInstance() {
    }

    // new method
    private addMoreInitilization() {
        // my logic needs to be tested using junit
    }

}

Answer 1

You can extend the "ApplicationStartUp" in your tests. Then override the unwanted methods. This way, you can create an Object of the subclass and call the method "addMoreInitialization" of the super class.