Raible Designs

AppFuse Light converted to Maven modules, upgraded to Tapestry 5 and Stripes 1.5

This past week, I stayed up a couple of late nights to do some of the AppFuse Light work I wrote about in October. I converted all web frameworks to Maven modules, as well as made them inherit from the appfuse-web project. Below is what the new module structure looks like:

At this point, the project is ready to import into AppFuse's SVN project. Here's a list of other changes I made:

• Modules now depend on AppFuse's backend and allow you to use Hibernate, JPA or iBATIS as the persistence framework. Implementations for Spring JDBC, OJB and JDO have been removed.
• Upgraded to JWebUnit 2.1, which now uses HtmlUnit under the hood and has much better JavaScript support. It also has Selenium support, but I've yet to try it.
• Ajaxified Body integrated into all frameworks. You can easily turn it off by modifying the global.js file.
• Prototype and Scriptaculous loaded from Google's Ajax Libraries CDN.
• Upgraded to Tapestry 5. Mad props to Serge Eby and his tapestry5-appfuse project for showing me how to do this. Serge became a committer on AppFuse recently, so hopefully we'll continue to see great things from the Tapestry 5 support. I really like the clean URLs and minimum configuration required in Tapestry 5. It's testing framework is nice too, but I believe it could be improved.
• Upgraded to Stripes 1.5. This was easy and painless. I'm definitely a fan of Stripes and look forward to reading the Stripes book on my bookshelf.
• Dropped support for: Struts 1.x, WebWork, Spring MVC + Velocity.

If you want to try any of these applications, you can create archetypes using the following commands:

svn co https://appfuse-light.dev.java.net/svn/appfuse-light/trunk appfuse-light
cd appfuse-light/preferred-web-framework
mvn archetype:create-from-project
cd target/generated-sources/archetype
mvn install
cd ~/dev
mvn archetype:generate # The new archetype should show up as an option

Next steps include figuring out a way to flatten the inherited dependencies and plugins so archetype:create-from-project can create truly standalone projects. Please let me know if you have any questions.

Dojo/Comet support in Java Web Frameworks

This week I'm doing a research project for a client. The main purpose of the project is to find out which Java-based web framework works best with Dojo and Comet. Here's the key requirement from the client:

It's all about Comet, we want Comet everywhere we can put it, but we want to isolate the icky bits of fiddling with pages with JavaScript. We're kind of wed to the Dojo implementation of the client-side bit, so we may as well use more of the Dojo widgets for a richer UI. For us, "works best with" needs to pay a certain amount of consideration to "fits naturally with", if you understand what I mean. I know that any framework that lets you spit out raw HTML will let you hand code in your Dojo / Comet, but that's certain to become very tiresome very quickly.

The candidate frameworks they asked me to look at are Wicket and Tapestry 5. They're willing to upgrade to Struts 2 since they're already using Struts 1. However, they don't feel that action-based frameworks naturally lead to rich UIs, so they'd prefer a component-based framework. They're currently using Seam for an administration-type application and feel it's too heavy for their customer-facing application.

Here's what I've found so far in my research. Please let me know if anything is incorrect.

• Tapestry 5 doesn't have Dojo or Comet support (Prototype and Scriptaculous are the baked-in Ajax frameworks).
• Struts 2 has old (version 0.4.3) and somewhat deprecated Dojo support. The developers seem to be in favor of removing it and promoting people hand-code Dojo instead. Struts 2 doesn't have support for Comet.
• Wicket has support for Dojo 1.1 that includes Comet support. This was written by Stefan Fußenegger and posted to the mailing list last month. I e-mailed Stefan and asked him about documentation. His response: "I lost my ambition to document it properly since I didn't receive any feedback on the mailing list. :)"

At this point, it seems that if the client really wants to use Dojo, they should use Wicket, and possibly pay Stefan to document it properly. However, they're willing to consider other options, as long as they have Comet support.

One option I thought of is to use DWR and its Reverse Ajax/Comet support. Another option would be to add better Dojo support to Tapestry 5. However, I don't think this is possible since the Prototype/Scriptaculous code is generated by the framework and would likely require a changes to switch it to Dojo.

Are there any other Java-based web frameworks that support easily creating Dojo widgets and working with Comet? Keith Donald tweeted that Spring MVC has Dojo support. However, I believe it's only for widgets and it still requires you to write JavaScript. If your framework doesn't have Dojo/Comet support, how hard would it be to add it?

Update: I also posted this question on LinkedIn. Make sure and check my question for additional thoughts from folks.

RE: Which is the Hottest Java Web Framework?

The "Break it Down" Blog has a lengthy post on Which is the Hottest Java Web Framework? Or Maybe Not Java? Comparing Java Web Frameworks is hard because so many people are passionate about the framework they know best. Add a couple more like Flex and Ruby on Rails and its downright difficult. Nevertheless, this post is good in that it contains a lot of pretty trend graphs and it looks like the author has done some good research. It's likely the folks that will scream foul are the ones that did poor in the comparison (Tapestry and Stripes, I'm talking about you).

Surprising among the top Java Web Frameworks is the rise of Struts 2:

To quote:

Which is much more interesting I think is how Wicket adoption has stayed almost flat while Struts 2 adoption has spiked. Spring MVC/WebFlow seems to be going no where fast and racing JBoss Seam there.

The popularity of Struts 2 really caught me off guard with it being quite a bit different from Struts 1, I figured it got thrown into the "just another web framework" category, but I guess there is something in a name and it's doing quite well.

Regardless of what you think of the post and trends, you have to appreciate the amount of time the author put into it.

Should we change AppFuse to be Struts 2-specific?

Dusty recently posted an interesting idea to the AppFuse developers mailing list:

After thinking/coding/reading for a while I think the more interesting task is: Retool AppFuse to be one or more Struts2 plugins based on various higher level app patterns. (AppFuse Facebook, AppFuse Employee DB, AppFuse Blog, AppFuse Basic LDAP, AppFuse Basic Crowd).

This all comes from the fact, that I have been wanting to refactor the AppFuse web layer for Struts. One of the interesting aspects of AppFuse is that it works pretty much the same across all its web frameworks. It does so with some lowest common denominator abstractions that can be ported and look and work the same across frameworks. I have picked my tool(s): Struts 2 and Ruby On Rails when I want to pretend I am young again. I know Spring MVC, JSF, etc. but I have no desire to build significant apps on those platforms. It's not because they suck and Struts2 rules, it is because I know Struts 2 the best, I am most efficient there and it provides everything I need to build great webapps (Let's not devolve to a framework debate). So, I would rather have a more Struts 2-specific web stack, that really leverages conventions born and raised there. The nice thing about the Struts 2 web stack is that it is complemented nicely by AppFuse's data/service layer, since unlike Grails or Rails, Struts 2 has no data or service layer. [Read More »]

Seems like a good idea to me. What do you think?

Someday I'd like to come up with a "compatibility test" that allows others to improve upon the ideas in AppFuse and develop their stacks independently. A suite of Selenium tests that require extensionless URLs might be a good start.

AppFuse 2.0.2 Released

The AppFuse Team is pleased to announce the release of AppFuse 2.0.2. This release includes upgrades to Spring Security 2.0, jMock 2.4, the ability to customize code generation templates and many bug fixes.

For information on upgrading from 2.0.1, see the Release Notes or changelog. AppFuse 2.0.2 is available as a Maven archetype. For information on creating a new project using AppFuse, please see the QuickStart Guide or the demos and videos.

To learn more about AppFuse, please read Ryan Withers' Igniting your applications with AppFuse.

The 2.0 series of AppFuse has a minimum requirement of the following specification versions:

• Java Servlet 2.4 and JSP 2.0 (2.1 for JSF)
• Java 5+

If you've used AppFuse 1.x, but not 2.x, you'll want to read the FAQ. Join the user mailing list if you have any questions.

Thanks to everyone for their help contributing code, writing documentation, posting to the mailing lists, and logging issues.

Please post any issues you have with this release to the mailing list.

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?

Java Web Framework Smackdown at TSSJS in Vegas

This year's TSSJS is starting to look like an excellent conference. I'm particularly excited to be moderating the following Expert Panel.

Java Web Framework Smackdown: Struts 2, Spring MVC, Grails, Seam/JSF and Wicket
The leading advocates of today's popular Web frameworks will duel under the Vegas Lights. Come and learn when to use your favorite framework and to see if it can live up to its hype.

We're talking about productivity, scalability and maintainability of Java-based Web applications. The emerging trend is that simplicity is better and productivity matters. Furthermore, if maintainability is the most costly part of any application -- how do these frameworks perform?

Attend if you're a Java Web developer, or if you simply like good entertainment. A working knowledge of the popular Java Web framework options will make this session more fun. If you haven't worked with any framework, come and learn who has the best spokesman.

I plan on bringing the boxing bell from OSCON 2005 to make this session one of the best in the show. I'll be coming up with a list of questions for these experts in the next couple of months. In the meantime, if you have any suggestions, please let me know.

With a venue like The Venetian, why wouldn't you go?

AppFuse 2.0.1 Released

The AppFuse Team is pleased to announce the release of AppFuse 2.0.1. This release squashes a number of bugs and includes an upgrade to Spring 2.5. To learn more about Spring 2.5's features, see InfoQ's What's New in Spring 2.5: Part 1 article.

For information on upgrading from 2.0, see the 2.0.1 Release Notes or changelog. AppFuse 2.0.1 is available as a Maven archetype. For information on creating a new project using AppFuse, please see the QuickStart Guide or the demos and videos.

What is AppFuse? Click here to find out.

AppFuse is an open source project and application that uses open source tools built on the Java platform to help you develop Web applications quickly and efficiently. It was originally developed to eliminate the ramp-up time found when building new web applications for customers. At its core, AppFuse is a project skeleton, similar to the one that's created by your IDE when you click through a wizard to create a new web project.

AppFuse 1.x uses Ant to create your project, as well as build/test/deploy it. AppFuse 2.0 uses Maven 2 to create your project as well as build/test/deploy it. IDE support is much better in 2.0 because you can generate the IDE project files with Maven plugins. AppFuse 1.x uses XDoclet and JDK 1.4+.

This project was started in April 2003.

The 2.0 series of AppFuse has a minimum requirement of the following specification versions:

• Java Servlet 2.4 and JSP 2.0 (2.1 for JSF)
• Java 5+

If you've used AppFuse 1.x, but not 2.x, you'll want to read the FAQ. Join the user mailing list if you have any questions.

Thanks to everyone for their help contributing code, writing documentation, posting to the mailing lists, and logging issues.

We greatly appreciate the help from our sponsors, particularly Atlassian, Contegix, JetBrains, and Java.net. Atlassian and Contegix are especially awesome: Atlassian has donated licenses to all its products and Contegix has donated an entire server to the AppFuse project. Thanks guys - you rock!

Please post any issues you have with this release to the mailing list.

Go Light with Apache Struts 2 and REST by Don Brown

After attending Dan's talk on REST, I stayed in the same room and listened to Don Brown talk about Struts 2's support for building RESTful applications. Below are my notes from the event.

What is wrong with today's web applications? You're using a modern web framework and you've cleanly separated your presentation and business logic. The biggest problem in modern web applications is Confusing URLs.

A URL should be a resource indicator - not a method invocation. Often, web applications have little or no caching. People use GET to perform data manipulation and POST may or may not change state (especially with JSF). Another big issue with modern web frameworks is there's too many abstraction layers that hide HTTP headers and it's difficult to manipulate them.

Today's applications are "information silos". There's a lot of information in your applications, but it's all buried in HTML, JavaScript and CSS. There's no way to get this information out of your application unless you explicitly expose it.

The answer to many of these problem is REST. It's the Way of the Web. To solve the information silo problem, you can create a single interface that has multiple representation of the same resource. There's one URI for all types of resources - be it XML, JSON or HTML. How does this work w/o modifying the URL? You modify the URL's extension.

Struts 2 has a couple of plugins that make developing RESTful services easier. The first is the Codebehind plugin and the 2nd is the REST plugin. Don is doing a demo with the REST plugin and shows that there's no Struts configuration files needed (no struts.xml and no struts.properties). The only thing that's necessary is to specify an "actionPackages" init-param on the DispatcherFilter in web.xml. This activates the Codebehind plugin that uses conventions to determine the view template's path.

In Don's demo, he's creating an "OrdersController" that implements ModelDriven. After implementing a setId() method (to set the id from the request parameters), a getModel() method (to return the Order object) and implementing a show() method that returns HttpHeaders, Don starts up his server and shows that http://localhost:8080/order/5 returns an HTML page. Changing the URL to end in /5.json returns JSON, /5.xml returns XML.

public HttpHeaders create() {
    service.save(order);
    return new DefaultHttpHeaders("success").setLocationId(order.getId());
}

The Poster Plugin for Firefox is great when you're working with REST services. Don used this plugin to show us that it's possible to post to JSON and get back JSON results. His demo was impressive, especially the fact that there was no XML configuration required for Struts. I also like how the DefaultHttpHeaders class allows you to manipulate headers in a type-safe manner.

To use the REST plugin, you'll want to use Struts 2.1. If you're using Maven, all you need to depend on is struts-rest-plugin. The struts-codebehind-plugin (as well as struts-core) will be pulled in by transitive dependencies.

One disadvantage of REST vs. WS-* is you can't generate client code from a WSDL. You'll have to write your client by hand. However, one advantage of REST is there's already lots of clients - your browser, curl, etc.

The Struts REST Plugin hasn't been officially released, but hopefully will be in Struts 2.1.1. You can checkout the code from SVN using the URL below. The documentation is located here.

http://svn.apache.org/repos/asf/struts/struts2/trunk/plugins/rest

Great talk Don - and excellent work on the REST plugin for Struts. I can't wait to try it out.

Comparing JVM Web Frameworks Presentation

Early this morning, I assembled a Comparing JVM Web Frameworks presentation in preparation for my talk tomorrow at ApacheCon. As mentioned on Monday, this presentation compares Flex, Grails, GWT, Seam, Struts 2 and Wicket. While I think this presentation would be fun to deliver, I don't believe it has as much meat as the original talk I was planning to give. My original talk compares JSF, Spring MVC, Stripes, Struts 2, Tapestry and Wicket. Since I've used all these frameworks, I'm able to compare them more on their technical features. Since I haven't used Flex, GWT or Seam, there was no way for me to 1) try them all before tomorrow and 2) do a thorough analysis of how well they each handle my desired features.

Since the abstract on ApacheCon's website mentions my original presentation, I don't want to yank out the carpet and present the second without asking. So my plan is to ask the audience which one they'd rather hear and continue from there. I've updated both presentations with the latest statistics and uploaded them for your review. For those of you who've used these frameworks, I'd be interested to hear how accurate you think my Pros and Cons section is. If you know of better pros or cons, please let me know and I'll adjust as needed.

• Comparing JSF, Spring MVC, Stripes, Struts 2, Tapestry and Wicket
• Comparing Flex, Grails, GWT, Seam, Struts 2 and Wicket

While creating the 2nd presentation, I found a couple things that surprised me. The first is how popular Flex is - not only in job listings, but also in skilled developers and mailing list traffic. Below is a graph that shows how there aren't many jobs for most of the frameworks, but there's lots for Flex.

The following graph illustrates while I chose to use Flex instead of OpenLaszlo as the Flash framework. OpenLaszlo has a much smaller community than Flex.

The second thing that was surprising is Seam doesn't have a logo! How does it ever expect to become a popular open source project without a logo?! It's amazing they've made it this far without having this essential feature. To motivate the creation of a Seam logo, I'm using the following butt-ugly logo in my presentation (found here). Hopefully something better comes along before I deliver my talk tomorrow.

Update: Monday's post started an interesting thread on Stripes' mailing list. Also, I really like Spring MVC's new annotation support. It'd be nice to see it go a step further and use defaults (like ControllerClassNameHandlerMapping + subpackage support) and only require annotations to override the defaults. IMO, Stripes, Spring MVC and Struts 2 are all excellent choices if a request-based framework provides the best architecture for your application.

Update 2: Comparing Flex, Grails, GWT, Seam, Struts 2 and Wicket seems to gave gained a lot of interest (and support) in the blogosphere. Because of this, I'm considering submitting it as a JavaOne talk. If I were to do this, how would you like to see this presentation changed and improved?

Update 3: I received the following Seam logo via e-mail. Thanks Christian!

Update 4: I've updated the Dice.com graph to include "Java" with every search term. To understand the comments on this entry, you might want to view the previous graph.

Update 5: This presentation was posted to the Wicket User mailing list. I followed up asking users to post the pros and cons of Wicket. Now there's a lengthy thread on Wicket's Pros and Cons. Good stuff.