Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #15392

Re: "Small" Program Challenge.

From Lew <lewbloch@gmail.com>
Newsgroups comp.lang.java.programmer
Subject Re: "Small" Program Challenge.
Date 2012-06-18 13:31 -0700
Organization http://groups.google.com
Message-ID <b9f48b24-bc75-490d-84fb-56e4acb8d1ae@googlegroups.com> (permalink)
References (6 earlier) <IqxDr.28704$hJ3.24051@newsfe14.iad> <jrmaju$u48$1@news.albasani.net> <jrmbpg$6ik$1@speranza.aioe.org> <20ad5d23-f0a7-4926-9d99-b9dc0a7ea18e@googlegroups.com> <jro181$dp7$1@speranza.aioe.org>

Show all headers | View raw

On Monday, June 18, 2012 12:57:53 PM UTC-7, javax.swing.JSnarker wrote:
> On 18/06/2012 3:47 PM, Lew wrote:
> > Loading does not imply initialization, and in fact cannot.
> 
> Wrong. Loading and initialization go hand-in-hand.
> 
> > The JVM is forbidden to initialize a class except under specific
> > circumstances, a
> 
> What?

See JLS 12.4, which I cited upthread:
<http://docs.oracle.com/javase/specs/jls/se7/html/jls-12.html#jls-12.4>
"A class or interface type T will be initialized immediately before the first occurrence of any one of the following:

- T is a class and an instance of T is created.

- T is a class and a static method declared by T is invoked.

- A static field declared by T is assigned.

- A static field declared by T is used and the field is not a constant variable (§4.12.4).

- T is a top level class (§7.6), and an assert statement (§14.10) lexically nested within T (§8.1.3) is executed.

A reference to a static field (§8.3.1.1) causes initialization of only the class or interface that actually declares it, even though it might be referred to through the name of a subclass, a subinterface, or a class that implements an interface.

Invocation of certain reflective methods in class Class and in package java.lang.reflect also causes class or interface initialization.

A class or interface will not be initialized under any other circumstance."

> 
> >> Exactly. It loads the specified class, as part of which that class's
> >> static initializer runs. And if it's an enum, the enum elements'
> >> initializers run too.
> >
> > Not true. Loading does not imply initialization, and in fact is forbidden to.
> 
> Wrong. Loading and initialization go hand-in-hand.

Not according to the JLS. What authority are you using?

> > The initializers only run under specific circumstances, separately from
> > loading.
> >
> > I have cited the relevant JLS sections.
> 
> You haven't cited anything except my own post, and your quotation of 
> *that* was a jumbled mess with some sections repeated for some reason.

Again, I quoted the section I re-quoted in this post. I provided the link 
*and* quoted the relevant content. How can you say I didn't?

> > False premise, unreliable conclusion.
> 
> On your part, Lew.
> 
> > Loading does not imply initialization.
> 
> Wrong. Loading and initialization go hand-in-hand.

Except according to the JLS.

> >> However, the observed behavior seems to be out of spec. The main
> >> method's absence should prompt an error upon the attempt to invoke it,
> >
> > Indeed.
> 
> And not before.
> 
> When invoking a static method of a non-loaded class, the standard 
> procedure always has been:
> 
> Load the class.
> Initialize the class.

Note - that is two steps, not one.

> Invoke the method.
> 
> In particular, the spec requires that in this:
> 
> class A {
>      static int x;
> 
>      static { x = 100; }
> 
>      static int foo () { return x; }
> }
> 
> a call to A.foo() should return 100, not 0. If it can attempt to invoke 
> foo before the static initializer has executed that would be violated.

It can attempt to call 'foo()' before the initializer has executed. This is 
exactly one of the circumstances that causes the initializers to execute.

Read the JLS! I have referenced and quoted the relevant section twice now.

> On the other hand, it complaining that a reflective call to A.bar() 
> can't be resolved sooner than the loading and initializing of A as part 
> of trying to resolve bar is equally anomalous. If it hasn't loaded and 

I haven't seen any examples of reflection in this thread. Regardless, 
"certain reflective methods" invoked will cause initialization.

> initialized A yet, how can it be sure whether or not it has a method 
> bar? On the other hand, if it's a non-reflective call the code calling 
> bar won't even compile.

-- 
Lew

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

"Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-13 13:45 -0700
  Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-13 13:52 -0700
    Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-13 16:17 -0700
      Re: "Small" Program Challenge. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-06-14 00:16 +0000
    Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-13 16:19 -0700
      Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-13 16:24 -0700
    Re: "Small" Program Challenge. markspace <-@.> - 2012-06-13 17:40 -0700
  Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-13 21:28 -0400
  Re: "Small" Program Challenge. Roedy Green <see_website@mindprod.com.invalid> - 2012-06-13 20:52 -0700
    Re: "Small" Program Challenge. "Hiram Hunt" <hiramhunt@verizon.net> - 2012-06-14 08:23 -0400
      Re: "Small" Program Challenge. "Hiram Hunt" <hiramhunt@verizon.net> - 2012-06-14 08:30 -0400
    Re: "Small" Program Challenge. Arne Vajhøj <arne@vajhoej.dk> - 2012-06-17 21:17 -0400
  Re: "Small" Program Challenge. Paul Cager <paul.cager@googlemail.com> - 2012-06-14 02:32 -0700
  Re: "Small" Program Challenge. Bent C Dalager <bcd@pvv.ntnu.no> - 2012-06-14 11:29 +0000
  Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-14 12:50 -0700
  Re: "Small" Program Challenge. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-14 15:49 -0500
  Re: "Small" Program Challenge. Gene Wirchenko <genew@ocis.net> - 2012-06-14 14:56 -0700
  Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-14 17:02 -0700
  Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-14 17:09 -0700
  Re: "Small" Program Challenge. Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2012-06-15 22:13 -0700
    Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-16 12:11 -0700
  Re: "Small" Program Challenge. Wanja Gayk <brixomatic@yahoo.com> - 2012-06-17 15:22 +0200
    Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-17 15:24 -0700
      Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-17 18:25 -0400
        Re: "Small" Program Challenge. Arne Vajhøj <arne@vajhoej.dk> - 2012-06-17 20:31 -0400
          Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-17 20:55 -0400
            Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-17 20:40 -0700
              Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-17 23:43 -0400
              Re: "Small" Program Challenge. Lew <noone@lewscanon.com> - 2012-06-17 21:25 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 00:45 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 12:47 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 15:57 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 13:31 -0700
                Re: "Small" Program Challenge. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-18 16:05 -0500
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 14:18 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 19:50 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 19:48 -0400
                Re: "Small" Program Challenge. David Lamb <dalamb@cs.queensu.ca> - 2012-06-19 08:07 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 15:26 -0400
                Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-18 09:04 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 13:09 -0400
                Re: "Small" Program Challenge. markspace <-@.> - 2012-06-18 11:06 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 14:46 -0400
                Re: "Small" Program Challenge. markspace <-@.> - 2012-06-18 13:22 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 19:51 -0400
                Re: "Small" Program Challenge. Wanja Gayk <brixomatic@yahoo.com> - 2012-06-20 13:11 +0200
                Re: "Small" Program Challenge. Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-06-22 12:54 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-22 18:30 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-25 12:59 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-25 16:49 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 12:44 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 16:01 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 13:36 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 20:01 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-18 18:25 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 22:01 -0400
                Re: "Small" Program Challenge. Gene Wirchenko <genew@ocis.net> - 2012-06-18 19:04 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-18 22:12 -0400
                Re: "Small" Program Challenge. Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-06-19 12:36 +0000
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 15:28 -0400
                Re: "Small" Program Challenge. Gene Wirchenko <genew@ocis.net> - 2012-06-19 09:12 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 15:30 -0400
                Re: "Small" Program Challenge. Gene Wirchenko <genew@ocis.net> - 2012-06-19 15:04 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 18:23 -0400
                Re: "Small" Program Challenge. Gene Wirchenko <genew@ocis.net> - 2012-06-19 15:32 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 19:09 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 19:10 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-19 17:19 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 20:42 -0400
                Re: "Small" Program Challenge. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-19 20:01 -0500
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-19 21:12 -0400
                Re: "Small" Program Challenge. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-06-19 20:32 -0500
                Re: "Small" Program Challenge. Lew <noone@lewscanon.com> - 2012-06-19 22:01 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-20 21:15 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-20 21:05 -0400
                Re: "Small" Program Challenge. Wanja Gayk <brixomatic@yahoo.com> - 2012-06-23 13:42 +0200
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-23 12:12 -0400
                Re: "Small" Program Challenge. Wanja Gayk <brixomatic@yahoo.com> - 2012-06-23 23:10 +0200
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-23 17:14 -0400
                Re: "Small" Program Challenge. Lew <noone@lewscanon.com> - 2012-06-19 22:15 -0700
                Re: "Small" Program Challenge. Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-06-20 10:34 +0000
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-20 10:45 -0700
                Re: "Small" Program Challenge. Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2012-06-21 08:13 +0000
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-21 17:18 -0400
                Re: "Small" Program Challenge. Lew <lewbloch@gmail.com> - 2012-06-21 15:30 -0700
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-21 20:28 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-20 21:22 -0400
                Re: "Small" Program Challenge. "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2012-06-20 21:19 -0400

csiph-web