Raible Designs

Zero Configuration in Struts 2

Struts 2 has a nifty zero configuration feature. However, it's only useful for registering actions, not for automatically registering results. In other words, you still have to use an @Result annotation to tell your action what page to dispatch to. To use default view names instead of requiring @Result, you can use the Codebehind Plugin. Also, did you know Struts 2 will autowire your Spring dependencies? It's pretty slick.

What does this all mean? It means you can write your Struts 2 application without writing any XML. Of course, you can still use XML to tweak behavior, but with these plugins enabled, you won't have to.

IMO, these plugins should be combined into a single zero configuration feature.

Here's how you can enable Struts 2's Zero Configuration feature in AppFuse 2.0:

1. Add a packageNames parameter to the "struts" filter in your web.xml:
   

   <filter>
       <filter-name>struts</filter-name>
       <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
       <init-param>
           <param-name>actionPackages</param-name>
           <param-value>com.company.newapp.webapp.action</param-value>
       </init-param>
   </filter>
   

2. Add the Codebehind Plugin as a dependency in your pom.xml:

   <dependency>
       <groupId>org.apache.struts</groupId>
       <artifactId>struts2-codebehind-plugin</artifactId>
       <version>2.0.6</version>
   </dependency>
   

3. Add a struts.codebehind.pathPrefix constant in struts.xml for your default pages directory:

   <constant name="struts.codebehind.pathPrefix" value="/WEB-INF/pages/"/>
   

That's it - now you can code away without configuring anything!

How does this compare to other web frameworks in AppFuse? Tapestry has a similar feature, but Spring MVC and JSF don't. Spring MVC still requires you create a bean definition for Controllers and JSF requires you write a chunk of XML for each managed bean. Of course, if you know how to do something similar with Spring MVC or JSF, please let me know.

Comparing Java Web Frameworks at ApacheCon Europe

It's been almost 2 1/2 years since I created and presented my "Comparing Web Frameworks" talk at ApacheCon 2004. It's hard to believe that was my first talk in front of a large audience. Before that conference, I posted a list of possible topics, as well as an outline a few days later. The most recent time I presented this talk was at Spring Forward 2006.

At this year's ApacheCon Europe, I'll be presenting Comparing Java Web Frameworks again. This time, I'll be adding Wicket and Stripes to the mix. I'm adding these two because they seem to be getting the most hype in Java developer's blogs. Of course, it would be great to add Grails, RIFE and Seam, but that's just too much to cover in an hour. Also, Grails is just Spring MVC and Seam uses JSF - so RIFE is the only one that stands out as unique. Here's the current session description:

One of the most difficult things to do (in Java web development) today is pick which web framework to use when development an application. The Apache Software foundation hosts most of the popular Java web frameworks: Struts, MyFaces, Tapestry and Wicket. This session will compare these different web frameworks, as well as Spring MVC and Stripes. It will briefly explain how each works and the strengths and weaknesses of each. Tips, tricks and gotcha's will be plentiful. Lastly, it will provide attendees with a sample application that utilizes all 6 frameworks, so they can compare line-by-line how the frameworks are different. This sample application will include the following features: sortable/pageable list, client and server-side validation, success and error messages as well as some Ajax functionality. The frameworks will be rated on how easy they make it to implement these features.

Over the next couple months, I'll try to post a revised outline so all the folks who care about a comparison like this can voice their opinions. I'll also be integrating Stripes and Wicket into AppFuse and AppFuse Light.

I'm still not sure about the name "AppFuse Light", but it's probably better than "AppFuse LE" which doesn't seem to convey the concept enough. The problem with "Light" is how to spell it (Bud Light vs. Miller Lite). The nice thing about AppFuse LE is we can shorten it to ALE. Regardless, you gotta love how it can all be related back to beer.

I've never been to Amsterdam before, so I'm definitely looking forward to this trip. My dad will be joining me, so I'll probably do more site-seeing that conference-going. If you're from the area, do you have any suggestions on what to do and where to stay? My dad has been pricing tickets and thinks we'd be better off flying into Frankfurt, spending a few days in Germany, and then arriving a day or two before my talk (on Friday). However, Queen's Day is the Monday of the conference and I've heard rumors it shouldn't be missed. I've got some Dutch and German in my blood, so it should be fun to visit my ancestral homeland.

Simplified UI Tags in Struts 2

Struts 2.0.3 contains a much needed simplification of its UI tag libraries. Before 2.0.3, you had to define a property three times (in the value, label and name attributes):

<s:textfield label="%{getText('user.firstName')}" name="user.firstName" 
    value="%{user.firstName}" cssClass="text medium"/>

In 2.0.3+, you can use the "key" attribute to replace all these attributes. For example:

<s:textfield key="user.firstName" cssClass="text medium"/>

One of the things I really like about WebWork/Struts 2 is the previous examples have the ability to write out the entire form row, rather than just an input field. Even better, the markup rendered is customizable via FreeMarker templates.

The bad news is Struts 2.0.3 never got released because the struts-annotations project hasn't had a release yet (good ol' Mavenism). The good news is Struts 2.0.4 is rumored to be out by the end of the month. In the meantime, if you're using Maven 2, you can use AppFuse's repository to get the goods. Here's the repo settings you're need:

<repositories>
    <repository>
        <id>appfuse</id>
        <name>AppFuse Repository</name>
        <url>http://static.appfuse.org/repository</url>
    </repository>
    <repository>
        <id>struts-203-staging</id>
        <name>Apache Struts 2.0.3 Staging Repository</name>
        <url>http://people.apache.org/builds/struts/2.0.3/m2-staging-repository</url>
    </repository>
</repositories>

Yeah, I could just advise you to use AppFuse 2.0 - but we're having a hard enough time supporting our existing users.

[TSE] Keynote: The Bigger Picture with Adrian Colyer

We've seen a lot of things over the last few days, but what about the big picture? It's not just about the Spring Framework anymore, but there's also a lot of sub-projects: SFW, SWF, SWS, S-OSGi. Then there's Enterprise services: clustering, persistence, messaging and scheduling. Industry trends: SOA, Web 2.0/RIA, RAD stacks.

Agenda

• Spring portfolio: unifying themes, fitting the pieces together (by layer) and future direction
• Facing the feature: my boss says I need a SOA, from auto-suggest to RIA and the quest for ever-increasing productivity

[Read More]

[TSE] The Holy Grails of Web Frameworks with Guillaume LaForge

Under the hood, Grails uses Spring MVC. It has support for "flash scope" between requests.

I find it funny that flash scope is so popular these days, we've had this in AppFuse for four years. However, web frameworks didn't add native support for it until it had a name (provided by Rails). To be fair to Struts Classic, they had support for it before Rails was even invented.

Rather than JSPs, Grails uses Grails Server Pages, which look much like JSPs. Grails uses SiteMesh by default and allows you to easily change the layout used with a meta tag.

<meta name="layout" content="main"/>

Most of the dynamic attributes in a GSP are rendered using the various "g" tags. There's dynamic taglibs for logic (if, else, elseif), iterating, linking, ajax (remoteFunction, remoteLink, formRemote, submitToRemote), form (select, currencySelect, localeSelect, datePicker, checkBox), rendering (render*, layout*, paginate), validation (eachError, hasError, message) and UI (i.e. richtexteditor). [Read More]

[TSE] Designing Stateful Web Application Control Flow with Erwin Vervaet

Spring Web Flow (SWF) does not fit into an application or a feature where free-flow navigation is required. It works best where you need to lock down and control navigation. SWF is not designed to be a web framework, but rather to solve the specific problem of navigation and state management between many pages.

Erwin is a Senior consultant at Ervacon and has extensive experience using Java SE and Java EE. He is the inventor and co-lead of the Spring Web Flow project.[Read More]

[TSE] Using Dynamic Languages with Spring with Rod Johnson and Guillaume LaForge

Spring 2.0 has dynamic language support. To make it work, you do need a Java interface as a contract between callers and dynamic beans. There's no special requirements on the interface. It's a "POJI" and doesn't have to extend or implement anything. For example:

There's 3 ways of configuring Groovy beans:

1. GroovyScriptFactory <bean> element defining source location and properties
2. <lang:groovy> element from a <lang> namespace
3. POBD (Plain old <bean> definition) - this is unique for Groovy since it can be compiled into Java bytecode

[Read More]

[TSE] Rapid Web Application Development with Rob Harrop

There's a couple of other sessions I should probably go to, namely Juergen's talk on Transactions and Mark Fisher's Message Driven POJOs Rock! However, transactions is generally a pretty boring topic and I don't see myself developing any MDPs in the next two weeks. If you don't use your knowledge in two weeks, you generally lose it, so I'll wait to learn more about MDPs until someone pays me to. I know a fair bit already, so I don't know that there's a whole lot more to learn.

I'm attending Rob Harrop's Rapid Web Application Development Essentials talk. With any luck, I'll learn some new tips that we can use in AppFuse.[Read More]

Spring's "p" namespace and AppFuse Performance Tuning

After seeing Rod Johnson's post about Spring 2.0's "p" namespace, I'm wondering if it's something we should include in AppFuse? I don't think it's quite as intuitive as <property name="">, but I'm curious to see what users think. The biggest reason against using it is (AFAIK) neither Eclipse nor IDEA will give you code-completion on (whereas they will for <property name="">).

In other news, Matt Fleming has an excellent writeup on how he optimized AppFuse (Spring MVC flavor) to handle pages with large forms. His form was 38 MB worth of HTML when saved to disk so I doubt everyone will need this, but it certainly is interesting information. If there's enough demand, we'll make Matt's suggestions available options in an upcoming release.

Equinox (a.k.a. AppFuse Light) 1.7 Released!

This release's major new features are upgrading to Spring 2.0, Hibernate 3.2, an Ajax + Spring MVC version, an Acegi Security + Spring MVC version and Struts 2.0 as an optional web framework. It's highly likely that the "extras/security" package can be installed with other web frameworks, but it's only been tested with Spring MVC. Furthermore, this release provided all of the different combinations that Equinox provides - all 50 of them!

All of the frameworks used in Equinox, as well as most of its build/test system is explained in Spring Live. A summary of the changes are below (detailed release notes can be found in JIRA):

• Added extras/spring-ajax with examples of ajaxified displaytag (with AjaxAnywhere), in-place editing (Script.aculo.us), in-page updates (DWR) and lightbox (Lightbox gone Wild) popups.
• Added extras/security with Acegi Security integration for authentication and authorization.
• Automated creation and testing of all possible combinations for distribution.
• Converted from JSP to Facelets for JSF/MyFaces option.
• Integrated Ajax4JSF into JSF/MyFaces option.
• Added Struts 2.0.1 as web framework.
• Upgraded to Spring 2.0, including improved XML syntax and JSP Form Tags
• Added Cargo settings to pom.xml so it's possible to run web tests from Maven.
• Changed dataSource bean to use a connection pool.
• Added popup calendar (using jscalendar) to Spring MVC and Struts 2.
• Added OpenSessionInViewFilter for Hibernate and OpenPersistenceManagerInViewFilter for JDO/JPOX.
• Fixed foreign-language encoding issues with Spring's CharacterEncodingFilter.
• Changed from DAO to Dao to be more consistent with other projects.
• Dependent packages upgraded:
  • Canoo WebTest 1393
  • Cargo 0.8
  • Commons Validator 1.3.0
  • DWR 1.1.1
  • FreeMarker 2.3.8
  • jMock 1.1.0
  • JPOX 1.1.1
  • Hibernate 3.2
  • MyFaces 1.1.4
  • Spring 2.0
  • Spring Modules Validation 0.5
  • Struts 1.2.9
  • Tapestry 4.0.2
  • WebWork 2.2.4
• Dependent packages added:
  • Acegi Security 1.0.2
  • Ajax4JSF 1.0.2
  • AjaxAnywhere 1.2-rc2
  • Facelets 1.1.11
  • Struts 2.0.1

Download. For more information about installing the various options, see the README.txt file.

Demos:

• Spring · Spring + Ajax · Spring + Acegi
• JSF + Facelets
• Struts 1 · Struts 2
• Tapestry
• WebWork

Thanks to all the users of Equinox for making this a great release!

P.S. I'm fully aware that this project's name conflicts with an Eclipse project.