java : in what order are static final fields initialized?

Question

好的，假设我有一个看起来像这样的类(class):

public class SignupServlet extends HttpServlet {
    private static final Logger SERVLET_LOGGER=COMPANYLog.open(SignupServlet.class);
    private static final ExceptionMessageHandler handler = new ExceptionMessageHandler();   
    private static final SignupServletObservableAgent signupObservableAgent = 
        new SignupServletObservableAgent(null, SERVLET_LOGGER);
}

我可以指望类加载器按顺序初始化这些字段，以便我可以依赖 SERVLET_LOGGER 在 signupObservableAgent 之前实例化吗？

Answer 1

是的，它们按照它们在源中出现的顺序进行初始化。您可以在 The Java Language Specification, §12.4.2 中阅读所有血腥细节.见第 9 步，内容如下:

... execute either the class variable initializers and static initializers of the class, or the field initializers of the interface, in textual order, as though they were a single block, except that final class variables and fields of interfaces whose values are compile-time constants are initialized first ...