Question

Suppose I have a Utility class,

public class Utility {

    private Utility() {} //Don't worry, just doing this as guarantee.

    public static int stringToInt(String s) {
        return Integer.parseInt(s);
    }
};

Now, suppose, in a multithreaded application, a thread calls, Utility.stringToInt() method and while the operation enters the method call, another thread calls the same method passing a different s.
What happens in this case? Does Java lock a static method?

Answer 1

There is no issue here. Each thread will use its own stack so there is no point of collision among different s. And Integer.parseInt() is thread safe as it only uses local variables.