Static field initializer is being invoked after static method execution

Question

I've got a class with only static members, designed like that:

public class Clazz {

    public static final Foo foo = FooFactory.createFoo();

    private static Bar bar;

    public static void prepare() {
        bar = new Bar(foo);
    }
}

When calling Clazz.prepare(), I can see that foo is null at bar initializing. As far as I know, static initializer should be invoked just before the invocation of any static method of the class. Therefore, foo should already be initialized when prepare() is called. Am I missing something?

It doesn't return a null value. More that that, after prepare() has finished, foo is actually initialized, just **after** the method invocation. — basme, Nov 19 '15 at 14:49
@basme Basically is not good enough, [class initialisation can be tricky](http://stackoverflow.com/questions/30192250/how-are-object-dependencies-between-static-blocks-resolved/30192463#30192463). Can you please post a full code example that exhibits the odd behaviour? — biziclop, Nov 19 '15 at 14:49
@basme Then the question is: where do you call `Clazz.prepare()` from. — biziclop, Nov 19 '15 at 14:50

score 1 · Answer 1 · answered Nov 19 '15 at 14:47

1

FooFactory.createFoo() must be returning a null value

answered Nov 19 '15 at 14:47

Rafik BELDI

4,140
4
24
38

Which can also be caused by the value returned depending on `Clazz.foo`. – biziclop Nov 19 '15 at 14:47
An alternative problem is if `Clazz.prepare()` is called from the class initialiser of `Foo`, `FooFactory`, or `Bar`. – biziclop Nov 19 '15 at 14:50
1

@biziclop yes indeed but we must see FooFactory to tell. – Rafik BELDI Nov 19 '15 at 15:06

score -1 · Answer 2 · answered Nov 19 '15 at 15:18

-1

Actually, initializer of Foo calls Clazz.prepare() too. That's the reason. Thanks @biziclop for the idea.

answered Nov 19 '15 at 15:18

basme

81
9

Static field initializer is being invoked after static method execution

2 Answers2