final static SecureRandom.getInstanceStrong()

Question

Here is my annotated code.

class RandomThing{

// This is one way to do it, but I want more randomness.
    protected final static Random rand = new Random();

// This is how I do it with SecureRandom.
    protected final static Random rand = new SecureRandom();

// Here is the best way I can get a strong instance, but rand is no longer final.
    protected static Random rand = null;

    static {
        try {
            rand = SecureRandom.getInstanceStrong();
        } catch (NoSuchAlgorithmException ex) {
            // Blow up.
        }
    }
}

How can I have something like this?

protected final static Random rand = SecureRandom.getInstanceStrong();
// not okay because getInstanceStrong throws NoSuchAlgorithmException

*but rand is no longer final*: that's because you removed the `final` keyword. Add it back, and remove the useless `= null`. — JB Nizet, Apr 22 '14 at 21:25
@JBNizet If the field is `final` and `static` it needs to be initialized at declaration. — Sotirios Delimanolis, Apr 22 '14 at 21:27
@SotiriosDelimanolis: nope. A static block can initialize a static final field. It can't be initialized more than once, though. — JB Nizet, Apr 22 '14 at 21:34
@JBNizet Right. But because of the multiple branches...(is what I was missing) — Sotirios Delimanolis, Apr 22 '14 at 21:37
Just take the above RandomThing code, add `final` to the `rand` declaration, and remove the `= null`, and it will compile fine (if you remove the two other `rand` fields, of course). — JB Nizet, Apr 22 '14 at 21:38
@JB It doesn't. My IDE gives me an error for the exception that `SecureRandom.getInstanceStrong()` can throw. — Simon Kuang, Apr 22 '14 at 21:41
Put `rand = null` in the `catch` block (or do something else drastic, like throw an unchecked exception). — chrylis -cautiouslyoptimistic-, Apr 22 '14 at 22:03

final static SecureRandom.getInstanceStrong()

0 Answers0