Safe to synchronize on Class object?

Question

Is it considered safe and good practice for a method to synchronize on the Class object of it's own class? I am using lazy initialization for a static field; the field is initialized to null when the class is loaded and then set to its actual value the first time it is used. I need to make sure the actual initialization is thread safe. Here is a simplified example of what I am doing.
public class Test {
    private static String myField = null;
    public String foo() {
        synchronized (Test.class) {
            if (myField == null) {
                myField = "Hello world!";
        return myField;
}It seems like that should work, but I was a little worried that by locking the Class object I might cause a problem with the class loader or something.

Answer 1

jschell wrote:
Nick_Radov wrote:
I have to use lazy initialization rather than initializing the static field in clinit because it's value depends on a superclass field which isn't fully available until the class loader finishes loading the class. So the lazy initialization is just to get around that sequencing problem.Huh? That is certainly phrased oddly at best. If a "superclass" is used then it is fully loaded before it is used. There is no sequencing problem with that.He might have a design problem. He can se a partly initialized super class if that method is overridden and invoked by the parent constructor.
Kaj