Raible Designs

Building a Better Maven with Ant

It looks like the Ant folks are thinking of building a better Maven.

I see many developers adopt Maven because they want a build system able to provide common features with no effort. Most of them don't want to spend much time writing an Ant script, or have seen or heard that maintaining Ant build scripts is troublesome. So they choose to use Maven only because it's easy to use for common use cases: install, write a simple pom of a few lines or generate it using an archetype, and you're ready to compile, test and package your new project following the Maven standard structure. They also get dependency management for free, and with only a few more effort they have multi module builds, and some nice features like code analysis, coverage, and a set of report gathered in a web site. That's really nice and that's what I like about Maven.

But Maven suffers from a lack of flexibility and robustness IMHO. And later the same people who first adopted Maven because of its perceived ease of use become frustrated when they need to tweek the system to their own needs or don't understand how the release plugin work. Then some of them go back to Ant, first having to go through a sometimes painful road to describe their whole build system in xml, especially if they aren't Ant experts. Others try to use new build tools like raven, buildr or others.

I really like Ant, and think it is a very good basis for robust and flexible build systems. People with enough knowledge of Ant can write very good build systems, testable, maintainable and adaptable. But you need to get your hands dirty, and you need to get a good knowledge of some of the mechanisms which can make an Ant based build system manageable: import, scripts and scriptdef, macrodef, presetdef, and so on. [Read More]

What do you think - is this a good idea?

I agree that Maven has its warts, but I don't think it's that bad. I've also heard that Maven has been successfully implemented at large companyies like eBay, Intuit and E*Trade[1]. Is the "Maven sucks" meme largely something that exists in the blogosphere, but not in the real world?

I think the biggest benefit of Maven is dependency management. I think it makes your code more modular and easier to build. Rather than having a monolithic source-code tree that depends on itself being built in a certain order, you can have individual modules that pull dependencies from a central location. This can be done with Maven's Ant Tasks as well. I don't see a problem with building a better Maven with Ant, but to try and build a better Central Repository sounds like a nightmare to me. The current repository has been improved for years and is much better than it was a couple years ago. That being said, I would love to see somebody build a more accurate Central Repository. Ideally, it'd be done sometime next week.

[1] I could be wrong about these companies. If you're a developer at one of these companies, please confirm or deny. Any comments on Maven's success at these companies would be great as well.

Update: Speaking of Maven, there's an interesting comment on a Javalobby post I wrote:

With all the critical remarks the Maven project is receiving, wouldn't it be time for some Maven project lead to step up and explain the team's position? Or is it completely deaf to the sentiments? How many builds have to fail, how much more headaches are needed before others start their own version of Maven and do it the right way (like Don [Brown])?

Seems like an excellent question to me. Guys?

Maven 2 Archetypes get a much needed improvement

Yesterday, a new version of the Maven Archetype Plugin was released. This release incorporates many of the improvements that were developed in a different project - code named "Archetype NG". The two major improvements are 1) you only have to use "mvn archetype:create" now and 2) you can create archetypes from existing projects.

I haven't tried #2, but #1 seems to work pretty well (especially since AppFuse archetypes are the first 9 ).

[Read More]

Reviews: Getting Started with Grails, Rails for Java Developers and Groovy Recipes

Two weeks ago, I mentioned a number of books I was hoping to read to get up to speed on Rails and Grails quickly. Over the last two weeks, I was able to polish off three of these (listed in order of reading):

• Getting Started with Grails
• Rails for Java Developers
• Groovy Recipes

Below are short reviews of each book.

Getting Started with Grails
The Good: This is the perfect book to learn the basics of Grails quickly. At 133 pages, I was able to read this entire book in one sitting. The first couple chapters are very introductory, but likely necessary for beginners. The good news is you start writing your first Grails application on page 7 (Chapter 3).

Chapter 4 (Improving the User Experience) is good in that it shows you how to do warning, error and confirmation messages. This is something often overlooked in web frameworks and Rails and its "flash" concept seem to have made it important again. I remember way back in 2003 when I complained about frameworks not allowing messages to live through a redirect - everyone said it was something you didn't need. Now it's a standard part of most web frameworks.

The Bad: Uses Grails 0.3.1. This is understandable since the book was written in 2006 and published in 2007. Also, it doesn't cover testing that much (5 pages). If testing is so easy with Groovy and if Grails has Canoo WebTest support built-in, it should be shown IMO.

Rails for Java Developers
The Good: This was an interesting book for me because it uses AppFuse for many of its Java-based examples. Unfortunately, it uses the Struts 1.x version which is cumbersome and verbose as far as Java web frameworks go. The most impressive part of this book is how Justin and Stu do an excellent job of walking the line and not insulting Java nor developers using it. They provide an easy to understand view of Rails from a Java Developer's perspective. There's detailed chapters on ActiveRecord (as it compares to Hibernate), ActiveController (compared to Struts) and ActiveView (compared to JSP). This book has excellent chapters on Testing, Automating the Development Process and Security.

The Bad: This book was published over a year ago, so it uses an older version of Rails. This means some commands don't work if you're using Rails 2.0. It's also a little light on Ruby, so I didn't feel I learned as much about the language as I was hoping to. That's understandable as it's more of a Rails book than a Ruby book.

Groovy Recipes (Beta from Jan 3, 2008)
The Good: I really like the style of this book and that it shows you how to get things done quickly with code samples. It's very no-nonsense in the fact that it contains a lot of code and howtos. I really like Scott's writing style and found this book the easiest to read of the three. This may have something to do with my eagerness to learn Groovy more than anything. The most refreshing part about this book is how up-to-date it is. Because it's a Beta, it seems to contain the most up-to-date information on Groovy and Grails. After reading Getting Started with Grails and working with it for a couple weeks, the first Grails chapter seemed a little basic - but that's likely because I've figured out how to mix all those recipes already. The Grails and Web Services chapter definitely has some interesting content, but I've rarely had a need to implement these recipes in a real-world environment. I'd rather see recipes on testing the UI (with the WebTest plugin) and how to use GWT and Flex with Grails. If SOUIs are the way of the feature, this is a must.

The Bad: Not much information on testing with GroovyTestCase, mock objects or implementing Security. If one of Groovy's sweet spots is testing, why isn't there more coverage on this topic? The Java and Groovy integration chapter is especially good, but there's very limited information on Ant and Maven. It's likely the websites provide sufficient documentation, but the Maven section only fills 5 lines on an otherwise blank page. The biggest problem I have with this book is I really like the recipes writing style and would love to see more tips and tricks. At 250 pages, I was able to finish this book with pleasure in a few days.

What's Next?
Now I'm reading JRuby on Rails (Apress) and Programming Groovy (Pragmatic Programmers). Following that, I'll be perusing dead-tree versions of Struts 2 Web 2.0 Projects (Apress), Prototype and script.aculo.us (Pragmatics) and Laszlo in Action (Manning). If any publishers want to send me books on GWT and Flex, I'd be happy to add them to my list.

Groovy, Rails needs Components, RIA Frameworks compared and faster WebTests

Here's some interesting snippets I found while reading blogs today:

• Stop writing plain old Java code. Groovy obsoletes plain old Java. We ought to just say "Java 7 = Groovy" and move on. -- Stuart Halloway
• So far my experience is that I love the Ruby language and don't want to go back to doing Java except when/if I need to to pay the bills. But Rails I'm not as sold on. Mind you I'm not here to bash on Rails, there are some great things there and other people have done a fine job of praising them. But there are some things I definitely miss from Tapestry, and the most significant one is components. -- MysteryCoder
• If you're looking for maximum control over presentation and the best possible appearance for the finished product, I would say Flex is probably the way to go. If you're a Java developer using Java on the server side, or you just can't stand the thought of having your app run in the Flash player and would prefer JavaScript, GWT is probably going to work out very well for you. Open Laszlo is going to offer a great deal of platform versatility, but at the expense of some polish and features available in the other two frameworks. - Kevin Whinnery in Three RIA Platforms Compared: Adobe Flex, Google Web Toolkit, and OpenLaszlo
• A new experimental feature of WebTest allows to specify the number of threads that should be used for the tests what can bring enormous speed improvements without modification of the tests. -- Marc Guillemot

To summarize: use Groovy over Java, Rails needs components, Flex is the best RIA framework and WebTest keeps getting better. These aren't my words, but I don't see much fault in them either.

Don Brown Makes Maven 2 Not Suck

Don Brown spent some time over the weekend Making Maven 2 not suck:

While there are a few (very important, I might add) things Maven 2 gets right, there are a bunch that just suck, yet I use it at my day job (Atlassian) and in Open Source work, so in true Open Source tradition, rather than continue bitching, I'm doing something about it. I'm embarking on a quest to fix all the bits of Maven 2 that really annoy me and waste my time. I hope to get most, if not all, of the changes back into the codebase, but my personal deliverable is a build of Maven 2 that doesn't suck.

On his blog, Don lists a number of improvements he hopes to make. This weekend, he implemented the first three, which concentrates on speeding up remote repository access and downloading of artifacts.

First up, tasks #1-3. I implemented these changes in a bored Sunday afternoon and saw a example build (Struts 2 core) go from 3 minutes, 26 seconds to 2 minutes even, so a little over 40% performance improvement.

Interested, I decided to try Don's improvements on AppFuse. Since it fetches seemingly hundreds of artifacts from Maven's central repository, it seemed like a good testing ground. With a clean repository (rm -r ~/.m2/repository), a 8 MB/sec internet connection and "mvn -Dmaven.test.skip", I achieved the following results with the stock version of Maven 2.0.8:

[INFO] Total time: 7 minutes 40 seconds
[INFO] Finished at: Mon Jan 28 09:02:11 MST 2008
[INFO] Final Memory: 55M/508M

With Don's improved uber-jar, I received the following results:

[INFO] Total time: 5 minutes 17 seconds
[INFO] Finished at: Mon Jan 28 09:10:56 MST 2008
[INFO] Final Memory: 56M/508M

460 vs. 317 seconds = a 31.1% improvement -- Nice work Don!

When he implements #4 (Should support artifacts checked into the SCM in the lib/ directory so no external repository needed), I'll be a much happier Maven consumer. I've always wanted the ability to bundle all of AppFuse's dependencies for offline use like we did in 1.9.x.

Don - I'll buy you numerous beverages in Vegas if you add the ability to run a Maven command to put all a project's dependencies in its lib directory too.

All Java web frameworks should support hot deploy of a single class

In Anyone else using Groovy?, Tim Fennell (inventor of Stripes) raves at how much he likes Groovy now that it supports Java 5 features. He writes that Groovy might offer a solution to make development with Stripes faster:

The other thing I've been wondering about is that if there were enough demand for it we could try adding "improved" groovy support. E.g. throw your groovy actions under WEB-INF and we'll use groovy's built in stuff to do auto-reloading etc.

Gregg Bolinger responds with an excellent idea:

It would be really cool if Stripes could automatically discover and load changes to action beans (including new ones) without the entire app restarting, regardless of what the action bean is written in. But I realize that is a pretty tall order. :)

I agree that it might be a tall order, but I don't think it's impossible. In fact, I think all Java-based web frameworks should support hot deploy of a single class. We shouldn't have to buy JavaRebel to do this. It should be mandatory.

When an application reaches a certain size, the startup time can get pretty lengthy. This is lost development time. Furthermore, if any part of the development cycle takes longer than 15 seconds, there's a good chance developers will do something else (check their e-mail, move onto another task, etc.). Multi-tasking may be a good skill to have, but it's a horrible way to be productive.

Of the frameworks I'm familiar with, only Tapestry 5 and Seam support reloading single classes without restarting the whole application. Why can't the other frameworks "borrow" Tapestry 5's code? Maybe someone should just buy ZeroTurnaround and give away JavaRebel for free.

If I had one wish for 2008, it would be for all Java web frameworks to support this feature. Pretty Please?

Migrating a Rails app to Grails

There's an interesting trend I've seen happening at companies over the last year. More and more, they're experimenting with Rails and/or Grails for both prototyping and real applications. I think this is an excellent use for these frameworks as they both are very productive. The reasons for their productivity is simple: zero turnaround and less code.

For a Java-based company that's built their bread and butter applications on Java and been successful with it, both frameworks can be disruptive. Bread and butter applications tend to be large and somewhat difficult to maintain. In my experience, the biggest maintenance headache is not writing code or fixing bugs, it's the turnaround time required to make changes, run tests and build the application to test in your browser. Since Rails and Grails eliminate the turnaround, it's only natural for developers at companies with a lengthy build process to love their increased productivity.

Over the next couple weeks, I'm going to do some experimenting with porting a Rails application to Grails. Why? Because I think companies are going to have a difficult time choosing between these two frameworks for rapid prototyping and (possible) production deployments. While both frameworks are great for prototyping, the last thing most developers want to do is throw away the prototype and develop it with something else. They want to continue to enhance the prototype and eventually put it into production. With Rails and Grails (and many others), it's possible to build the real application in a matter of weeks, so why shouldn't it be put into production?

For most Java-based companies, putting a Rails application into production is unfamiliar territory. However, a Grails application is just a WAR, so they can continue to use all the Java infrastructure they know and love. So for companies with an established, tuned and successful JVM infrastructure, does it really make sense to use Rails over Grails? The only thing I can think of is language reasons - there's a lot of Ruby fanatics out there.

So again, the purpose of my experiment is simple: to see if a Grails app can do everything a Rails app can. As for language features and scalability, I'm not really concerned with that right now. I'm not looking to prove that either framework should be used for all web applications - just certain types.

Has anyone out there ported a Rails application to Grails? If so, are there any gotchas I should watch out for?

NOTE: I realize that Rails can be deployed on the JVM with JRuby. However, I think many companies have existing Java-based tools (logging, JMX, Spring backends, etc.) that more easily integrate with Grails than Rails. I could be wrong.

FreeMarker vs. JSP 2

I've been doing quite a bit of prototyping with Spring MVC and Struts 2 with both JSP and FreeMarker in the last few months. I'm trying to migrate a proprietary servlet-based framework with a proprietary JSP compiler to something that's open source. There's a couple of important features that the proprietary view framework has:

1. It's expression language allows methods to be called with arguments.
2. Templates can be loaded from a JAR on a remote server.
3. XML in variables is escaped by default.

For #1, I've found this to be impossible with JSP EL or JSTL. I've created JSP functions that allow argument passing, but they don't allow overloading of functions. FreeMarker solves #1.

For #2, JSPs again fail because the templates have to be on the file system or in a WAR. FreeMarker solves this problem as well.

For #3, neither JSP or FreeMarker solve this problem. I realize it can be fixed in FreeMarker by hacking the code - I've done the same with Tomcat and solved it for JSP as well.

So based on the requirements in this project, FreeMarker is the clear winner. Here's some problems that I see with using it:

• No XML escaping of expressions by default
• No compile-time checking of expressions
• IDE support is limited to Eclipse (meaning very little in the way of code-completion)

FreeMarker users - are there other problems you've experienced when using FreeMarker in your applications?

RE: Why Grails doesn't use Maven

Graeme Rocher's in Why Grails doesn't use Maven:

In his post entitled "Grails - The Good, The Bad and the Ugly", Jonas has some nice praise for Grails, his main beef is that it is not built on Maven.

So I wanted to clarify why exactly we chose not use Maven (by default) and the explanation is there for all to see in Jonas' first example of creating a Grails application vs creating a Maven project:

Instead of

grails create-app name

could be just

mvn archetype:create -U\
-DarchetypeGroupId=net.liftweb\
-DarchetypeArtifactId=lift-archetype-blank\
-DarchetypeVersion=0.4\
-DremoteRepositories=http://scala-tools.org/repo-releases\
-DgroupId=your.proj.gid -DartifactId=your-proj-id

My goodness, what a mouthful the Maven example is. There is a common acronym in the open source world called RTFM (read the *ing manual), when a user asks a question on a mailing list and the "experts" respond by pointing them to the place in the manual.

I think Maven's biggest problems are 1) poor metadata in the central repository and 2) the source of metadata in projects (pom.xml).

I believe #1 can be fixed if the Maven guys allow dependencies to be fixed based on user feedback. It's also gotten a lot better in recent years. In reality, maintaining transitive dependencies is hard and I believe Maven has done a good job. In reality, they're the only ones that slurp up transitive dependencies, so the only other option is to maintain the dependencies yourself.

To fix #2, I think the problem is mainly XML and the verboseness of the elements-only pom.xml that Maven requires. Most of the contents of a pom.xml are either dependencies, plugins or exclusions/variances of Maven's conventions. What if Maven's metadata was pluggable? What if XML was only one option? What if you could write a pom.groovy and describe your entire build process in 5 lines instead of 500? That would be very cool.

I'm still a Maven fan, mostly because it's greatly simplified the maintenance of and releasing of AppFuse. When I do GWT, Seam or Grails development in the future, you can be sure I'll try to use Maven to do the development. Why? Because I've learned how to use it and I don't feel the pain that so many others talk about. I also think it really shines on really large projects (builds that produce 30+ WARs for example). An Ant-based system on really large projects can become quite burdensome and difficult to maintain. Not only that, but it's very difficult to maintain a modular build system (where you can build/test/deploy a single WAR) with Ant. In my experience, really large Ant-based systems take forever to process that everything is up-to-date whereas Maven systems depend on each other and require you to keep them up to date. Sure it requires you to be smarter and run "mvn install" on your subprojects, but I'd rather do that than wait 5 minutes for Ant to process everything just to run a test.

You might remember that the main reason I used to prefer Ant over Maven was speed. That was in Maven 1 days. With Maven 2, speed is no longer a problem and I've found it much easier to run "mvn jetty:run" than "ant deploy" and wait for Tomcat to restart. IMO, the perfect development environment is one were you can run a command-line command (or use your IDE to start the server) and code away without worrying about restarts. Seam and Grails offer this environment, but it's unlikely your entire organization is going to use standardize on those frameworks and not have anything else. I think Maven and the Maven Jetty Plugin offer a nice alternative for the rest of those applications.

GWT Presentation with Bob Vawter

Tonight I'm in Mountain View attending the inaugural meeting for the new Silicon Valley Google Technology User Group (SV-GTUG). The good news about this meeting is Bob plans to discuss some of the new features in the GWT 1.5 release. Although it is not available yet, it sounds like they are putting the finishing touches on the 1.5 release and that it will be available soon.

The first ting I've learned is that GWT is actually pronounced "gwit". Bob is a member of the GWT team and he's the only one that's not based out of Atlanta. GWT has a very Swing-like programming model. It has widgets, panels and windows and operates very much like a traditional UI programming API. To create an application, you create a class that implements EntryPoint. Below is an example Hello World application.

One of the really nice things about GWT is that you can easily debug your application in your favorite Java IDE. GWT doesn't prevent you from writing JavaScript - you can insert native JavaScript into your code using a special /*-{ script here }-*/.

When you compile a GWT application, you get a whole bunch of stuff. When trying to develop cross-browser JavaScript code, you often end up with "if soup" to handle the different browsers. GWT does the same thing, but it creates different versions of the application for the different browsers. The naming of these files is an MD5 hash that's bootstrapped by a simple JS file. GWT files are all static and the file sizes are ~40KB/each for the Hello World application.

If you have to write fewer than 100 lines of code, it's likely that GWT will be overkill - you can do it with JavaScript easier. Once you get more lines of code and larger teams, Java's tools do all the heavy lifting. Yes, you can create large applications with large teams with scripting languages, but Java is the clear winner when you have large teams of developers working on projects.

GWT provides a RemoteService for client code and a RemoteServiceServlet for server-side code that you can use to implement RPC calls. For more information, see the Remote Procedure Calls documentation.

At this point, we're 45 minutes into the presentation and it's pretty disappointing. This is likely because there's no presentation and Bob doesn't seem to have any sort of agenda. I think this type of presentation would work well if folks had experience with GWT and were asking lots of questions. However, it seems that most folks haven't used GWT - so the questions (and his resulting answers) aren't very meaty.

One attendee asked about making GWT applications SEO-able. Bob's suggested solution is to continue to use Servlet or JSPs to render the page, but then use GWT to for the user interaction that needs to happen within the page. The RootPanel class has a get(String id) method that can be used to put the GWT application into a particular div or other placeholder.

Google Base and Google Checkout are currently using GWT. There's also a lot of Google internal development that uses GWT. Apparently, there's quite a few applications built with GWT that haven't launched yet.

Has anyone used the Maven Gwt Plugin? It sounds like it might be pretty nice as it contains the GWT compiler with no OS-dependent Google tooling.

The main new feature in GWT 1.5 is Java 5 support. There's also a GWT Incubator that's used to host GWT features that may go into GWT's core. You can view the demos online.

GWT's mission statement:

GWT's mission is to radically improve the web experience for users by enabling developers to use existing Java tools to build no-compromise AJAX for any modern browser.

GWT's competition according to Bob - Visual Studio.