CODEWITHSUNDEEP
javaoopstaticabstract-classstatic-methods
Daulet Nurgali
Daulet Nurgali

Reputation: 65

Abstract vs No instance approach?

I have one class (class util) for generating password(it has only one public static method ). Here two ways are : To make it abstract so no one can create its instance 

public abstract  class PasswordGenerator {

  public static String randomstring(int lo, int hi) {
     // Some logic , doesn't matter 
      return "";
  }
}

or to make its constructor private. So What's the best approach to do that ?

public class PasswordGenerator {

  private PasswordGenerator() {

  }

  public static String randomstring(int lo, int hi) {
    // Some logic , doesn't matter 
    return "";
  }
}

So What's the best approach to do that ?

Upvotes: 0

Views: 57

Answers (2)

Spotted
Spotted

Reputation: 4091

Make both the class final and the constructor private.

With the final keyword you clearly express the intent that the class is not made to be inherited. With the private constructor you clearly express the intent that the class is not made to be instanciated.

public final class PasswordGenerator {

  private PasswordGenerator() {}

  public static String randomstring(int lo, int hi) {
    // Some logic , doesn't matter 
    return "";
  }
}

Upvotes: 1

mad_manny
mad_manny

Reputation: 1091

You should definitely not make the class abstract, as this might indicate to other developers, that it is intended to be extended (and therefor instantiated).

Having a class technically being able to be instantiated is a minor problem.

But in this SO thread you can see a workaround, that uses a private constructor in combination with making the class final.

Upvotes: 3

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