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Posted to dev@struts.apache.org by Wes Wannemacher <we...@wantii.com> on 2009/06/03 17:02:19 UTC
use of private final vs. protected
I am looking at subclassing JakartaMultiPartRequest and almost all of
the members are 'private final', but they are Lists and Maps, so I am
curious what the justification is... I want to subclass and get at the
data, obviously I'd have to change the declarations to protected, but
is final necessary? From what I can see, the only thing it guarantees
is that with each instance of JakartaMultiPartRequest, the Lists or
Maps will point to new instances. I guess what I'm wondering is if
there is an intention to follow a coding standard or something that
I'm missing because I don't see much point for these members to be
private or final (especially since it makes it pretty much impossible
for me to subclass it).
-Wes
--
Wes Wannemacher
Author - Struts 2 In Practice
Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
http://www.manning.com/wannemacher
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Re: use of private final vs. protected
Posted by Musachy Barroso <mu...@gmail.com>.
I think it is a case of "one standard per developer" :). IMO "private"
and "final" should be used carefully in a framework, as people are
always doing things we didn't expect them to do. I have that problem
at work, where I have to "copy and paste reuse" code, because parts
that I need to overwrite are private for no reason.
musachy
On Wed, Jun 3, 2009 at 8:02 AM, Wes Wannemacher <we...@wantii.com> wrote:
> I am looking at subclassing JakartaMultiPartRequest and almost all of
> the members are 'private final', but they are Lists and Maps, so I am
> curious what the justification is... I want to subclass and get at the
> data, obviously I'd have to change the declarations to protected, but
> is final necessary? From what I can see, the only thing it guarantees
> is that with each instance of JakartaMultiPartRequest, the Lists or
> Maps will point to new instances. I guess what I'm wondering is if
> there is an intention to follow a coding standard or something that
> I'm missing because I don't see much point for these members to be
> private or final (especially since it makes it pretty much impossible
> for me to subclass it).
>
> -Wes
>
> --
> Wes Wannemacher
> Author - Struts 2 In Practice
> Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
> http://www.manning.com/wannemacher
>
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> To unsubscribe, e-mail: dev-unsubscribe@struts.apache.org
> For additional commands, e-mail: dev-help@struts.apache.org
>
>
--
"Hey you! Would you help me to carry the stone?" Pink Floyd
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Re: use of private final vs. protected
Posted by Martin Cooper <ma...@apache.org>.
On Thu, Jun 4, 2009 at 7:21 AM, Wes Wannemacher <we...@wantii.com> wrote:
> On Thu, Jun 4, 2009 at 9:54 AM, Martin Cooper <ma...@apache.org> wrote:
> >
> >
> > Ha! Old code always comes back to haunt, no? ;-)
> >
> > Yep, I did a lot of work on that code a few years ago, partly in support
> of
> > Struts 1 and partly in support of extensibility (which I never got around
> to
> > documenting properly, but which worked like a charm). I handed the reins
> > over, though, at about the time the streaming API came along. While I
> also
> > did a lot of work on the S1 wrapper, I haven't even looked at the S2
> > wrapper, so I'm not sure you really want me messing with it. ;-) Still,
> if I
> > can find some time lurking under a rock somewhere, I can try to keep tabs
> on
> > what you're up to (assuming there's a "plan" of sorts).
>
> Am I supposed to plan? You might as well fire me now then :)
I used quotes advisedly. ;-) All I meant was that I can only realistically
comment on what you're doing if I have some idea of the end goal.
--
Martin Cooper
> -W
>
> --
> Wes Wannemacher
> Author - Struts 2 In Practice
> Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
> http://www.manning.com/wannemacher
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@struts.apache.org
> For additional commands, e-mail: dev-help@struts.apache.org
>
>
Re: use of private final vs. protected
Posted by Wes Wannemacher <we...@wantii.com>.
On Thu, Jun 4, 2009 at 9:54 AM, Martin Cooper <ma...@apache.org> wrote:
>
>
> Ha! Old code always comes back to haunt, no? ;-)
>
> Yep, I did a lot of work on that code a few years ago, partly in support of
> Struts 1 and partly in support of extensibility (which I never got around to
> documenting properly, but which worked like a charm). I handed the reins
> over, though, at about the time the streaming API came along. While I also
> did a lot of work on the S1 wrapper, I haven't even looked at the S2
> wrapper, so I'm not sure you really want me messing with it. ;-) Still, if I
> can find some time lurking under a rock somewhere, I can try to keep tabs on
> what you're up to (assuming there's a "plan" of sorts).
Am I supposed to plan? You might as well fire me now then :)
-W
--
Wes Wannemacher
Author - Struts 2 In Practice
Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
http://www.manning.com/wannemacher
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Re: use of private final vs. protected
Posted by Martin Cooper <ma...@apache.org>.
On Wed, Jun 3, 2009 at 8:23 AM, Wes Wannemacher <we...@wantii.com> wrote:
> On Wed, Jun 3, 2009 at 11:14 AM, Al Sutton <al...@funkyandroid.com> wrote:
> > Back in the dim and distant past I remember final being used to give the
> JIT an optimization hint that whatever's described as final can be inlined
> as it won't change (note JIT not compiler). It's not a big saving, but in
> tight loops and heavily called code it can all add up.
> >
> > I found http://www.javaperformancetuning.com/tips/final.shtml which
> expands on it a bit.
> >
> > Al.
> >
>
>
> That makes sense, Al, but in cases like this (non-primitives) all it
> does is finalize the reference. So the referred objects are not
> immutable, and I guess I was just wondering whether the optimization
> that final provides in this case is worth the pain it causes for
> subclassing.
>
> I agree with Musachy, we should be careful using private and final,
> especially in struts since we inject objects like this. I figured I
> could subclass it, make some changes and then have the plugin define a
> bean overriding the definition that comes from core. With the fields
> defined the way they are, it's not possible. I'll make the changes to
> JakartaMultiPartRequest, but wanted to make sure I wasn't breaking
> some rule.
>
> Funny side-note... So I was reading all the JavaDocs on commons
> file-upload and low-and-behold, who wrote most of the classes I was
> looking at? Our own Martin Cooper! So, Martin, you wanna help out with
> enhancing struts2 file uploading capabilities? 8-D
Ha! Old code always comes back to haunt, no? ;-)
Yep, I did a lot of work on that code a few years ago, partly in support of
Struts 1 and partly in support of extensibility (which I never got around to
documenting properly, but which worked like a charm). I handed the reins
over, though, at about the time the streaming API came along. While I also
did a lot of work on the S1 wrapper, I haven't even looked at the S2
wrapper, so I'm not sure you really want me messing with it. ;-) Still, if I
can find some time lurking under a rock somewhere, I can try to keep tabs on
what you're up to (assuming there's a "plan" of sorts).
--
Martin Cooper
-Wes
>
>
> --
> Wes Wannemacher
> Author - Struts 2 In Practice
> Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
> http://www.manning.com/wannemacher
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@struts.apache.org
> For additional commands, e-mail: dev-help@struts.apache.org
>
>
Re: use of private final vs. protected
Posted by Wes Wannemacher <we...@wantii.com>.
On Wed, Jun 3, 2009 at 11:14 AM, Al Sutton <al...@funkyandroid.com> wrote:
> Back in the dim and distant past I remember final being used to give the JIT an optimization hint that whatever's described as final can be inlined as it won't change (note JIT not compiler). It's not a big saving, but in tight loops and heavily called code it can all add up.
>
> I found http://www.javaperformancetuning.com/tips/final.shtml which expands on it a bit.
>
> Al.
>
That makes sense, Al, but in cases like this (non-primitives) all it
does is finalize the reference. So the referred objects are not
immutable, and I guess I was just wondering whether the optimization
that final provides in this case is worth the pain it causes for
subclassing.
I agree with Musachy, we should be careful using private and final,
especially in struts since we inject objects like this. I figured I
could subclass it, make some changes and then have the plugin define a
bean overriding the definition that comes from core. With the fields
defined the way they are, it's not possible. I'll make the changes to
JakartaMultiPartRequest, but wanted to make sure I wasn't breaking
some rule.
Funny side-note... So I was reading all the JavaDocs on commons
file-upload and low-and-behold, who wrote most of the classes I was
looking at? Our own Martin Cooper! So, Martin, you wanna help out with
enhancing struts2 file uploading capabilities? 8-D
-Wes
--
Wes Wannemacher
Author - Struts 2 In Practice
Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
http://www.manning.com/wannemacher
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RE: use of private final vs. protected
Posted by Al Sutton <al...@funkyandroid.com>.
Back in the dim and distant past I remember final being used to give the JIT an optimization hint that whatever's described as final can be inlined as it won't change (note JIT not compiler). It's not a big saving, but in tight loops and heavily called code it can all add up.
I found http://www.javaperformancetuning.com/tips/final.shtml which expands on it a bit.
Al.
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-----Original Message-----
From: Wes Wannemacher [mailto:wesw@wantii.com]
Sent: 03 June 2009 16:02
To: Struts Developers List
Subject: use of private final vs. protected
I am looking at subclassing JakartaMultiPartRequest and almost all of
the members are 'private final', but they are Lists and Maps, so I am
curious what the justification is... I want to subclass and get at the
data, obviously I'd have to change the declarations to protected, but
is final necessary? From what I can see, the only thing it guarantees
is that with each instance of JakartaMultiPartRequest, the Lists or
Maps will point to new instances. I guess what I'm wondering is if
there is an intention to follow a coding standard or something that
I'm missing because I don't see much point for these members to be
private or final (especially since it makes it pretty much impossible
for me to subclass it).
-Wes
--
Wes Wannemacher
Author - Struts 2 In Practice
Includes coverage of Struts 2.1, Spring, JPA, JQuery, Sitemesh and more
http://www.manning.com/wannemacher
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