• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Maven Optimism
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Maven Optimism


  • Subject: Re: Maven Optimism
  • From: Chuck Hill <email@hidden>
  • Date: Wed, 9 Jul 2008 10:06:30 -0700

Hi Pierce,


On Jul 9, 2008, at 2:50 AM, Pierce T. Wetter III wrote:

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.

Lets place the blame where the blame belongs and make a more honest comparison. This is most NOT an Ant issue. It is a WOProject / build philosophy issue. The duplication between .classpath and some of the files in woproject/ are a deficiency in the woproject Ant tasks in that they currently can't use what is in .classpath. Mike is working on fixing this.


Now, what does maven do for this? Unless it is reading the .classpath file, it also has to somehow, somewhere duplicate the information that Eclipse uses. Duplication is duplication. And will Eclipse update the Maven information in the pom.xml when a new framework is added? When a new jar is added to the project? Or is that all manual pom fiddling?

The rest of the patternsets are also not an Ant issue, but a design philosophy in woproject (to not force a project layout). If you do use a project layout, as Wonder does, these can easily be rendered unnecessary.

Finally, build.properties:

principalClass=
project.name=
customInfoPListContent=
eoAdaptorClassName=
webXML=
webXML_CustomContent=
classes.dir=

If Maven does not use these and does not have a parallel system, then it has less flexibility. How would Maven handle it if the package name for the Application were changed in Eclispe?


Chuck


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
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden


--

Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems.
http://www.global-village.net/products/practical_webobjects






_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden


  • Follow-Ups:
    • Re: Maven Optimism
      • From: Henrique Prange <email@hidden>
    • Re: Maven Optimism
      • From: Lachlan Deck <email@hidden>
References: 
 >Maven Optimism (From: Pierce T.Wetter III <email@hidden>)
 >Re: Maven Optimism (From: Anjo Krank <email@hidden>)
 >Re: Maven Optimism (From: "Pierce T. Wetter III" <email@hidden>)

  • Prev by Date: Re: [Wonder-disc] HINT: If you ever switch to ERPrototypes ...
  • Next by Date: Re: Maven Optimism
  • Previous by thread: Re: Maven Optimism
  • Next by thread: Re: Maven Optimism
  • Index(es):
    • Date
    • Thread