How to destroy an singleton Object in Kotlin and force to call init block

Question

In Java, we can destroy the Singleton Object by below method.

public class MySingleton {
      private static MySingleton ourInstance = null;

  private MySingleton() {
  }

  public static MySingleton getInstance() {
      if(ourInstance == null)
          ourInstance = new MySingleton();
      return ourInstance;
  }

  private void destroy(){
      ourInstance = null;
  }
}

so the constructor will be called the next time.

In the same way how to destroy the Kotlin Singleton object.

object CacheManager{

  init {
     //some operations   
  }

  fun destroy(){
      //How to destroy?
  }

}

I need to destroy the Object and make the init block called again. How can I achieve this?

Answer 1

This is not possible in Kotlin; objects do not have the concept of being destroyed. If you need this possibility, you should not use an object, but instead use a regular class and implement the destroy logic manually, similarly to how you do this in Java.

Answer 2

I just converted your JAVA code to Kotlin using android studio and the result is looks like a singleton class which allows to destroy singleton object.

class MySingleton private constructor() {

    fun destroy() {
        ourInstance = null
    }

    companion object {
        private var ourInstance: MySingleton? = null

        val instance: MySingleton
            get() {
                if (ourInstance == null)
                    ourInstance = MySingleton()
                return ourInstance!!
            }
    }

    var b: String="Default value"
}

You can test this by following code

 var singleton:MySingleton= MySingleton.instance
 singleton.b="Singleton Object Initlized"
 Log.d("Value",singleton.b)
 singleton.destroy()
 singleton= MySingleton.instance
 Log.d("Reset",singleton.b)

May be this approach is wrong. If this is wrong then i will delete the answer, please let me know.