Alternatives to invoking instance method on static variable/method?

Question

I read that invoking instance methods on static variables/methods is considered bad practice( I don't know exactly why but that's not the question anyway).

Eg:

class Dice
{
    private int value;
    private static Random randomizer=new Random(); 
    
    public int setAndget_DiceValue()
    {
        value=randomizer.nextInt(6)+1; //Accessing static variable via instance class. Any alternatives?
        return value;
    }
}

What are then alternatives to modifying a static variable that doesn't involve invoking instance method? Even if I used a static method on randomizer, I would then have to use that instance method on a static method which is still considered bad practice.

Edit: Some places I first saw about this being considered a bad practice:

1 ) Writing to a static variable in an instance method, why is this a bad practice?

2 ) A comment to the OP's post: Can non-static methods modify static variables. He was a high-rep user so I was inclined to believe him.

3 )

Where have you read that it's bad practice? It's not. You have either misunderstood it, or taken it out of context. — Sweeper, Jun 28 '20 at 01:40
Nothing wrong with that code, but if your program is multithreaded, you should heed this note in the javadoc of [`Random`](https://docs.oracle.com/javase/8/docs/api/java/util/Random.html): *Instances of `java.util.Random` are threadsafe. However, the concurrent use of the same `java.util.Random` instance across threads may encounter contention and consequent poor performance. Consider instead using [`ThreadLocalRandom`](https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ThreadLocalRandom.html) in multithreaded designs.* — Andreas, Jun 28 '20 at 01:44
@Andreas, sorry I'm a beginner and haven't reached multithreading yet — HelloWorld, Jun 28 '20 at 01:47
1) Not applicable, since you are not writing to the static variable. 2) Not applicable, since you are not modifying the static variable. 3) Not applicable, since you are not returning the value of the static variable. — Andreas, Jun 28 '20 at 01:47

score 0 · Answer 1 · answered Jun 28 '20 at 01:48

Usually the static variables will be accompanied by, final so once initialized they cannot be reassigned with a different value inside the class.

The only invalid context would a static method trying to use a instance level variable or a method directly but I don't think the converse is invalid.

Alternatives to invoking instance method on static variable/method?

1 Answers1