>>
>> To give you some examples, for the current Wonder Ant builds,
>> between build.xml files, generic.xml, build.properties
>> files, .classpath and .patternset files, there are 5320 lines of
>> build configuration information in the current Wonder build. The
>> equivalent pom files are 2447 lines, which is not only more
>> efficient, but includes more information to help avoid the
>> jarmeggedon/jarhell problem.
>
> Rubbish.
>
> First, the build files are *way* lighter:
....Anjo counts the lines of xml in Build/build/*.xml...
>
>
> These 1500 lines build *all* of Wonder in the way you specify, with
> the values you specify and the order you specify. *And* they allow
> you to specify your own builds with just a build property and a
> symlink to a build file. You could also use includes or or add your
> own customizations, but the tasks they do are very light.
I may have miscounted by overcounting the symlinks to build.xml though
as I didn't notice those but I think you're undercounting by only
looking at Build/build/*.xml.
I'm using this as a measure:
wc -l `find . -name "build.xml" -print` Build/build/build-*.xml Build/
build/generic.xml `find . -name "build.properties" -print` `find . -
name "*.patternset" -print` `find . -name ".classpath" -print`
Because the problem as I've found with Ant is that the build
information is in all of those files, not just build.xml. This makes
it easier to use a single generic Ant build file, but to some extent
that's the whole point of maven in my mind. With Ant, everything is so
bloody explicit that you end up creating a sort of virtual maven via
Wonder's generic.xml.
To quote from "generic.xml":
2) to build your own projects that have the same layout as a wonder
project
So mvn/Wonder have the same approach. Standardize on a layout, so that
you can use the same build methodology everywhere. You use the same
recipe you get the same bread.
But I have to say, the ant build files are very complicated to
understand compared to the pom.xml files. In the past, I've found that
I end up having to grok all 1300 lines of Build/build/build.xml and
Build/build/generic.xml in order to debug the build of one of my
projects.
>
> Second, the individual build files build way more projects:
>
> macbook:Wonder ak$ find . -name build.xml|wc
> 67 67 2775
> macbook:Wonder ak$ find . -name pom.xml|wc
> 56 56 2121
You're looking at what you have, but I've rewritten all of those and
added new ones. I have files to build nearly everything in Wonder on
my system:
sierramadre:Wonder pierce$ find . -name pom.xml | wc
68 68 2440
>
> Thirdly from what I've seen, someone needs to change all these files
> whenever we bump a version. All of Ulrichs commits so far where
> these xml fixes. All *I* need to do is set one property.
I'm using a property in my pom.xml versions as well. So changing
all those files isn't really necessary, I can change the version by
changing the master pom.xml, same as you can. Eventually, I'll move
all the jar references up to the master pom, which will save me a line
per reference, and standardize the versions used.
>
>
> Fourth, adding a project typically requires five lines in Build/
> build/build.xml to add it to the correct group and some props. I
> might consider moving these props from the build file to a
> build.properties and making Build/build/build.xml only specify the
> inter-related deps.
Except you have to add the build dependencies somewhere as well,
which if you want to compare apples/oranges, you really have to count
right? You also have to count the information in build.properties. The
information in the pom.xml file for a new project without dependencies
is more then 5 lines, its like 10 lines, but 5 of those name the
project so you can reference it elsewhere and the other 5 reference
the super-pom.
>
>
> I'll grant you one point for the commons-logging versions, but I use
> neither ERJGroups or EROpenID. If I were and I'd be bothered, I'd
> figure out a way to keep them using only one.
>
>
It's not just that jar. WO uses commons-logging as well. The real
point here is that managing jar dependencies sucks. I know you feel
criticized but you shouldn't take it personal because I'm talking
about Wonder as my real point is that Wonder, which is widely used,
and considered pretty stable, has some jar dependency issues. The
solution to the jar problem that Wonder uses is the ERJars framework
for common jars, and Libraries directories for unique jars, but that
doesn't really solve the problem unless someone with Obsessive-
Compulsive-Disorder dedicates their life to keeping ERJars in sync.
Even then, what if you want some frameworks and not others from
Wonder, or you need the same (but newer version) jar in one of your
applications.
The maven solution is to document the dependencies, and setup a
whole bunch of infrastructure in order to be able to compute all that
stuff on the fly.
Again, you use the same recipe you get the same bread;
conceptually, ERJars functions as a maven repository, just one
manually maintained.
Having had to fight with a whole bunch of jar dependency issues in
production recently, I'm leaning more towards the maven way; as
opposed to trusting that every engineer will dutifully scour all the
other Libraries directories in all the other projects to see what's
needed where. Or even that I'll remember to push the missing jar into
production.
>
>
> So far we've seen that maven is neither more terse nor more powerful
> (at least in a way that would mean something to me).
I think maven makes a reasonable attempt to solve a really, really
annoying problem.
As far as terseness goes, perhaps that's not the right measure,
but generic.xml gives me the freaking willies, while pom.xml seems
stunningly obvious. I mean I really, really detest Ant build files.
I'd actually prefer regular make files.
>
> The other issues I have with it is that I actually *need* the
> flexibility in deployment structure. In some projects I *don't* want
> all-embedded builds as that stuff goes out of hand with 7 apps*all
> the frameworks. The resulting release tops 250M. So I want some of
> them embed only some jars. Show me how this works with maven
> *without* writing any "goals" or "mojos".
Well, now you're bottoming out my maven knowledge, as I'm not quite
sure what you're complaining about.
>
>
> So in summary, maven may or may not be nice. But I've been building
> Wonder with the build files for 7 years now and they haven't really
> changed a lot in this time. They do the roughly the same as some
> 20MB tool chain where you *still* have to write java plugins for.
And I have to maintain a build that's based on some stale snapshot
of the Wonder build files, and given a choice between grokking
generic.xml and or throwing it out and learning maven, I'm leaning
towards Maven, because its sucked so far. Of course, the latest Wonder
generic.xml looks a lot cleaner then what I have now, so that's not
necessarily a fair criticism. But maybe it is, because I would never
have dived into Wonder to tweak the Ant builds, but tweaking the Maven
builds was pretty simple.
But as I keep saying, you use the same recipe you get the same
bread. The Wonder Ant build and the Maven build at the end of the day
have to do the same steps and need the same information. Ant, being
more explicit, ends up pushing you towards a generic.xml type
solution, where every step in the build is spelled out explicitly, but
a certain folder layout is assumed, and certain things are stored in
external files. That way, you can use the same Ant build script over
and over.
Maven, being more implicit, ends up pulling the equivalent of
generic.xml into these plugin definitions based on the assumption that
all WO framework projects have to be built the same way for all
developers. That leaves the project specific information to be
specified somewhere like the project name and dependencies. Which goes
in one place, the pom.xml.
So at the end of the day, to use Wonder's generic.xml, you have to
setup your folder structure in a certain way and put certain
information in .classpath, .patternset, and .properties files. To use
maven, you have to setup your folder structure in a certain way and
put that same information in pom.xml. At the system level you have to
think of Ant as Ant plus the generic.xml you're using, and at that
point, Ant+Wonder Build Scripts == Maven. Maven just goes on to
leverage the information in the pom in other ways.
This title of this post is "Maven Optimism", following up from
"Maven Skepticism". I'm still a long way from being a maven expert,
but I've sort of refused to become an Ant expert. But so far, I'm a
lot more optimistic about being able to use Maven effectively. I think
it brings a lot to the table, and solves some tough development issues.
Pierce
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