Comparing JVM Web Frameworks at vJUG

A couple months ago, I was invited to speak at Virtual JUG - an online-only Java User Group organized by the ZeroTurnaround folks. They chose my Comparing JVM Web Frameworks presentation and we agreed I'd speak yesterday morning. They used a combination of Google Hangouts, live streaming on YouTube and IRC to facilitate the meeting. It all went pretty smoothly and produced a comfortable speaking environment. To practice for vJUG, I delivered the same talk on Tuesday night at the Denver Open Source Users Group.

The last time I delivered this talk was at Devoxx France in March 2013. I didn't change any of the format this time, keeping with referencing the Paradox of Choice and encouraging people to define constraints to help them make their decision. I did add a few new slides regarding RebelLabs' Curious Coder’s Java Web Frameworks Comparison: Spring MVC, Grails, Vaadin, GWT, Wicket, Play, Struts and JSF and The 2014 Decision Maker’s Guide to Java Web Frameworks.

I also updated all the pretty graphs (which may or may not have any significance) with the latest stats from Dice.com, LinkedIn, StackOverflow and respective mailing lists. Significant changes I found compared to one year ago:

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Posted in Java at Feb 06 2014, 10:54:17 AM MST 2 Comments

Switching AppFuse from MyFaces to PrimeFaces

When describing my bias against JSF back in November, I wrote:

... there's a lot of folks praising JSF 2 (and PrimeFaces moreso). That's why I'll be integrating it (or merging your pull request) into the 2.3 release of AppFuse. Since PrimeFaces contains a Bootstrap theme, I hope this is a pleasant experience and my overall opinion of JSF improves.

Shortly after the AppFuse 2.2.1 release in December, Gilberto Andrade contributed a sample project that used Mojarra (the JSF RI) and PrimeFaces instead of MyFaces and its Tomahawk components. Last week, I spent a few hours integrating Gilberto's changes into AppFuse's master branch. You can see all the changes I made (which include a Jetty plugin upgrade and some cleanup) in this Crucible review. Feel free to leave comments on ask questions in the review itself.

The first thing I noticed when integrating PrimeFaces is you have to add a custom repository in order to get its artifacts via Maven.

<repositories>
    <repository>
        <id>prime-repo</id>
        <name>Prime Repo</name>
        <url>http://repository.primefaces.org</url>
    </repository>
</repositories>

This is unfortunate since all of AppFuse's other dependencies can be found in Maven Central. It means that if you're using a JSF archetype, the PrimeFaces repo will be checked for artifacts first, causing an unnecessary slowdown in artifact resolution. I hope the PrimeFaces developers fix this soon.

While integrating these two frameworks, I ran into a number of issues.

An IllegalStateException on startup when using "mvn jetty:run"
The first issue I encountered was that I was unable to run the app in Jetty. It worked fine in Tomcat but I got the following error in Jetty:

2013-01-31 22:28:07.683:WARN:/:unavailable
java.lang.IllegalStateException: Application was not properly initialized at startup, could not find Factory: javax.faces.context.FacesContextFactory
at javax.faces.FactoryFinder$FactoryManager.getFactory(FactoryFinder.java:951)
at javax.faces.FactoryFinder.getFactory(FactoryFinder.java:316)
at javax.faces.webapp.FacesServlet.init(FacesServlet.java:302)
at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:492)
at org.eclipse.jetty.servlet.ServletHolder.doStart(ServletHolder.java:312)

I found the fix for this on Stack Overflow and added the following listener to my web.xml to solve it.

<listener>
    <listener-class>com.sun.faces.config.ConfigureListener</listener-class>
</listener>

Conditionally rendering a button disables its click-ability
The next thing I noticed was the Delete button didn't work when editing a user. It was hidden correctly when adding a user, but clicking on it to delete a user simply refreshes the page. Below is the code I used successfully with MyFaces. For some reason, this doesn't work with PrimeFaces.

<c:if test="${not empty userForm.user.id}">
<h:commandButton value="#{text['button.delete']}" action="#{userForm.delete}"
    styleClass="btn" onclick="return confirmMessage(msgDelConfirm)"/>
</c:if>

I also tried the following, but no dice. This is currently an open issue.

<h:commandButton rendered="${not empty userForm.user.id}" value="#{text['button.delete']}" 
    action="#{userForm.delete}" styleClass="btn" onclick="return confirmMessage(msgDelConfirm)"/>

The PrimeFaces Bootstrap theme 404s on some images
After integrating PrimeFaces' Bootstrap theme, the following error shows up in server logs.

[INFO] [talledLocalContainer] Feb 02, 2013 10:40:25 PM com.sun.faces.application.resource.ResourceHandlerImpl logMissingResource
[WARNING] [talledLocalContainer] WARNING: JSF1064: Unable to find or serve resource, images/ui-bg_highlight-hard_70_000000_1x100.png, from library, primefaces-bootstrap.

This seems to have happened before in previous releases and is currently an open issue.

Canoo WebTest doesn't work with fileUpload nor to set checkbox values
We use Canoo WebTest to run integration tests on the UI in AppFuse. For some reason, performing file uploads and setting checkbox values works fine with MyFaces/Tomahawk, but not with Mojarra/PrimeFaces. I'm not sure if this is caused by the JSF core or the component library, but it remains an open issue. For now, I've just commented out the parts of tests that used to do this.

On a related note, getting the real path of a resource from the ServletContext worked fine before the switch, but results in a null value now.

String uploadDir = getServletContext().getRealPath("/resources") + "/" + request.getRemoteUser() + "/";

PrimeFaces resources served up at /javax.faces.resource/* not found
While I didn't have problems with this in AppFuse, I did encounter it in AppFuse Light. I don't know why there was a difference between the two, but it turned out to be caused by the UrlRewriteFilter and my desire for extensionless URLs. The outbound-rule to strip .xhtml from URLs was the culprit. Adding a condition to it solved the problem. Yeah, the condition seems backwards, but it works.

<outbound-rule match-type="regex">
    <condition type="query-string" operator="equal">ln=primefaces</condition>
    <from>^(.*)\.xhtml(\?.*)?$</from>
    <to last="false">$1$2</to>
</outbound-rule>

Summary
The initial switch to Mojarra/PrimeFaces was pretty easy thanks to Gilberto's sample project. However, the small issues encountered after that turned out to be quite frustrating and you can see that several are still not fixed. I guess it just goes to show that not all web frameworks are perfect. Hopefully we'll get these minor issues fixed before the next release. In the meantime, you can checkout the updated demos for AppFuse JSF and AppFuse Light JSF.

Posted in Java at Feb 06 2013, 12:19:34 PM MST Add a Comment

Why the bias against JSF?

In my last post about InfoQ's Top 20 Web Frameworks for the JVM, I received a thought-provoking comment from henk53:

There is one little thing that does bother me in those presentations, and that's your fairly obvious bias against JSF.
...
If you are presenting yourself as, more or less, an authority on comparing web frameworks, then having a fairly obvious biased against one of them is just peculiar. I, all of my team, and various clients distrust your ranking of JSF. We do look at your data if the choice is between other frameworks, but as soon as JSF comes into the picture we just look elsewhere.

I'm not really sure where this bias comes from. Yes, JSF 1.0 sucked and 1.2 was only marginally better, but 2.0 is really cool and productive and there are SUPERB component and utility libraries now like PrimeFaces and OmniFaces. As a researcher of this topic I think you should keep up the date and not stick to some old grudge.

This is true, I am biased against JSF. It all started with my first JSF experience back in August 2004. If you remember correctly, 2004 was a big year: JSF 1.0, Spring 1.0 and Flex 1.0 were all released. The "AJAX" term was coined in early 2005.

History of Web Frameworks

By 2007 and 2008, JSF still hadn't gotten any better. In late 2009, JSF 2.0 was released and I upgraded in March 2011. As you can see from the aforementioned post, I ran into quite a few issues upgrading. JSF was also the hardest one to get working with extension-less URLs.

Most of my issues with JSF come from having maintained an application built with it since 2004. If I were to start a new application without any legacy migration issues, I imagine it wouldn't be as difficult. However, if you compare it to Struts 2 and Spring MVC, I've had little-to-no issues upgrading those applications over the years.

Also, I'm not just biased against JSF, but most component-based web frameworks. Just ask the Tapestry and Wicket folks. They've felt my criticisms over the years. My reason for preferring request-based frameworks like Struts 2/Spring MVC and Grails/Play has been because I've never seen the appeal in component-based frameworks. Often I've found that their components are just widgets that you can get from any decent JavaScript framework. And chances are that JavaScript framework can work with any web framework. Also, I've worked on a lot of high-traffic web applications that require statelessness for scalability.

I see the value in component-based frameworks, I just don't think components should be authored on the server-side. Most of the Java-based component frameworks require 2+ files for components (one for the component, one for the view, possibly one for the config). I love GWT's component concept in that you can just extract a class and re-use it. With JS frameworks, you can often just include a script. These days, when I think of good component-based frameworks, I think of jQuery UI and Twitter Bootstrap.

All that being said, there's a lot of folks praising JSF 2 (and PrimeFaces moreso). That's why I'll be integrating it (or merging your pull request) into the 2.3 release of AppFuse. Since PrimeFaces contains a Bootstrap theme, I hope this is a pleasant experience and my overall opinion of JSF improves.

In other component-based frameworks in AppFuse news, Tapestry 5 has gotten really fast in the last year. I imagine this is because we have a Tapestry expert, Serge Eby, working on it. And we're planning on adding Wicket in the 2.3 release.

So even though I prefer request-based frameworks with REST support and Bootstrap, that doesn't mean everyone does. I'll do my best to be less-biased in the future. However, please remember that my view on web frameworks is as a developer, not an analyst. And aren't developers supposed to be opinionated? ;)

Posted in Java at Nov 08 2012, 09:24:27 AM MST 11 Comments

Hyperproductive JSF 2.0 with Ed Burns at Jazoon

This morning, I attended Ed Burn's Talk on Hyperproductive JSF 2.0 at Jazoon. As you might know, I've been a critic of JSF for many years. However, it is one of the most used Java web frameworks, so I was hoping to learn how it's improved in the latest version. Below are my notes from Ed's presentation.

Ed's Plan for our Time Investment:

  1. Define a productive development environment
  2. JSF for greenfield and brownfield projects
  3. List the top 9 productivity killers with JSF projects and solutions

"I am always doing that which I cannot do, in order that I may learn how to do it." -- Pablo Picasso

Software is an executable representation of knowledge, a byproduct of learning how to solve a problem. Knowledge is something that changes as more information comes in. A productive environment makes it as easy as possible to learn how to solve a problem. Learning is an iterative process. Early iterations don't need to be optimal. Later iterations do ... and they need to be maintainable. First is the hardest. Fast iterations are they key. Spring Roo and Play are examples of frameworks that make the first iteration very fast.

You should use a tool to jumpstart JSF development: copy from an old project, use a Maven archetype or use your IDE. With greenfield development, you don't have to bother learning the byproduct of other people's learning. It's a great opportunity to pad your resume with the latest hot technologies. With brownfield development, it's vitally important to understand the existing solution and hidden assumptions. You're also much more constrained in your technology choices. If you want to change, you'll need to come up with a migration strategy, which can be difficult. JSF works well for both because it's not just a runtime framework, it's also a conceptual framework. You need to understand how your framework handles data conversion, validation, page flow, persistence integration, I18N, L10N, A11Y, Web standards and user friendliness.

Top 9 JSF Productivity Killers:

  1. Time wasting deployment step
  2. The perils of "there's more than one way to do it"
  3. Lengthy and painful developer on-boarding process
  4. Misused logging and misunderstood error messages
  5. Phantoms
  6. Under-utilized developer tools
  7. Premature optimization
  8. Difficulty in doing TDD
  9. Lack of an app framework

Time wasting deployment step
ZeroTurnaround solves this problem with JRebel, but there's other ways to do it. Some of the killers of flow state: 1) one large war file, 2) underutilizing dynamic language features, 3) complex server environment and 4) build process is redoing work unnecessarily. To stop the time wasting deployment step, the most important things you can do are as follows:

  • Configure your IDE correctly. In Eclipse, compile directly into WEB-INF/classes and use continuous compilation. With NetBeans, use GlassFish.
  • Don't do control-flow programming in XML.

Ed then showed a simple demo that showed how you can use Groovy to create a JSF UI Component. He also mentioned that Groovy can be used to author any JSF artifact. The benefit of this is you can simply edit and save a .groovy file without having to recompile or redeploy. Unfortunately, using Groovy didn't eliminate the XML syntax for pages or the XML for defining UI components.

The perils of "there's more than one way to do it"
JSF is very flexible, but flexibility is, more often than not, abused. There's a lack of convention for common things (e.g. master-detail, JSF concepts like converter, validator, etc.). The best way to fix this is to establish the norms for a project and stick with them. For example, Neil Griffin has a good blog entry for the different kind of managed beans you can create. Develop recommendations like Neil's and use them on all your projects.

Lengthy developer on-boarding process
Stick with standards when possible (at least have a common project description and build system across projects). Be committed to periodic cleanup cycles, including documenting for re-use. Pick one JSF component library and stick with it. Support for mixing and switching component libraries has improved with JSF 2, but it's still recommended you use only one.

Misused logging and misunderstood error messages
JSF is notorious for cryptic error messages and very long stack traces. It's still a problem, but the JSF Team is still working on improving them. Good tip: use the <ui:debug> tag. Its recordStateSize="true" attribute can be especially useful. If you're using PrimeFaces, add trace=true to request URLs.

Phantoms
Phantoms is when running code is not the same as the code you are modifying or wrong version of library gets picked up. You should have the capability to hit breakpoints anywhere in your entire software stack, including core Java sources. This is one of the most useful things about open source software. Solutions to phantoms: 1) put a timestamp on every redeploy and have the timestamp appear in the system log 2) write the running library stack to the system log (each library and version being used) and make it easy to compare one developer's runtime stack with another's 3) consider doing all work in tightly controlled VMs (checkout the VM at the beginning of the day, do your work, commit your changes and throw your VM away at the end of the day).

Under-utilizing developer tools
Make sure everyone has the fastest machines available and as much screen real estate as desired. Hardware is much cheaper than developer time. Another tip is to use Hudson as your butler. It's not just the team CI server. In other words, take advantage of automation wherever you can.

Premature Optimization
Keep in mind the trade-offs between readability and performance. When using frameworks such as JSF, don't try to outsmart the implementation. Rather, use the framework as intended and use open-source contributions to treat performance problems. Example, EL expressions got a lot faster between EE5 and EE6. If you spent time trying to optimize EL expressions, you might've been wasting your time.

Difficulty in doing TDD
Try to figure out why TDD is difficult in your company. For JSF, strongly consider JBoss's JSFUnit. Write your testcases to extend from Cactus ServletTestCase and leverage HtmlUnit (JSFUnit does this for you).

Lack of an app framework
Create common components: login panel, CRUD components, etc. If you don't have an app framework, build one over time.

Conclusion
This was an interesting talk by Ed. The dynamics of the room where a bit interesting. Jazoon is held in a movie theater, much like Devoxx. However, it appears there's a spotlight on the speaker that makes it very difficult to see the audience. I don't remember having this problem at Devoxx. Ed asked the audience quite a few questions, but it seemed he had a lot of difficulty in seeing if folks raised their hands. This made for some periods of awkward silence.

Personally, I was hoping to learn some new whizbang tips about JSF that I was not aware of. Unfortunately, I didn't learn anything new and wasn't that impressed with the Groovy demo.

I think Ed's tips about things outside of JSF were good, especially buying developers good hardware. I've seen many companies, including my current client, skimp on developer hardware and cause developer frustration because of it. I think it's great when companies provide developers top-of-the-line hardware and eliminate frustration over CPU and memory resources. LinkedIn and Time Warner Cable both provide their developers with Mac Pros and MacBook Pros as well as huge monitors. IMO, this is one of the best benefits you can provide your engineers.

Posted in Java at Jun 23 2011, 04:53:10 AM MDT 3 Comments

Upgrading to JSF 2

Last week, I spent a few hours upgrading AppFuse from JSF 1.2 to JSF 2.0. In reality, I upgraded from MyFaces 1.2.7 to 2.0.4, but all JSF implementations should be the same, right? All in all, it was a pretty easy upgrade with a few minor AppFuse-specific things. My goal in upgrading was to do the bare minimum to get things working and to leave integration of JSF 2 features for a later date.

In addition to upgrading MyFaces, I had to upgrade Tomahawk by changing the dependency's artifactId to tomahawk20. I was also able to remove the following listener from my web.xml:

<listener>
    <listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
<listener>

After that, I discovered that MyFaces uses a new URI (/javax.faces.resource/) for serving up some of its resource files. I kindly asked Spring Security to ignore these requests by adding the following to my security.xml file.

<intercept-url pattern="/javax.faces.resource/**" filters="none"/>

Since JSF 2 includes Facelets by default, I tried removing Facelets as a dependency. After doing this, I received the following error:

ERROR [308855416@qtp-120902214-7] ViewHandlerWrapper.fillChain(158) | Error instantiation parent Faces ViewHandler
java.lang.ClassNotFoundException: com.sun.facelets.FaceletViewHandler
        at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
        at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:401)
        at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:363)
        at org.ajax4jsf.framework.ViewHandlerWrapper.fillChain(ViewHandlerWrapper.java:144)
        at org.ajax4jsf.framework.ViewHandlerWrapper.calculateRenderKitId(ViewHandlerWrapper.java:68)
        at org.apache.myfaces.lifecycle.DefaultRestoreViewSupport.isPostback(DefaultRestoreViewSupport.java:179)
        at org.apache.myfaces.lifecycle.RestoreViewExecutor.execute(RestoreViewExecutor.java:113)
        at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:171)
        at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)

Figuring this was caused by the following element in my web.xml ...

<context-param>
    <param-name>org.ajax4jsf.VIEW_HANDLERS</param-name>
    <param-value>com.sun.facelets.FaceletViewHandler</param-value>
</context-param>

... I removed it and tried again. This time I received a NoClassDefFoundError:

java.lang.NoClassDefFoundError: com/sun/facelets/tag/TagHandler
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
        at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:392)
        at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:363)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:247)
        at org.apache.myfaces.shared_impl.util.ClassUtils.classForName(ClassUtils.java:184)
        at org.apache.myfaces.view.facelets.util.ReflectionUtil.forName(ReflectionUtil.java:67)

Since everything seemed to work with Facelets in the classpath, I decided to save this headache for a later date. I entered two issues in AppFuse's JIRA, one for removing Facelets and one for replacing Ajax4JSF with RichFaces.

The next issue I encountered was redirecting from AppFuse's password hint page. The navigation-rule for this page is as follows:

<navigation-rule>
    <from-view-id>/passwordHint.xhtml</from-view-id>
    <navigation-case>
        <from-outcome>success</from-outcome>
        <to-view-id>/login</to-view-id>
        <redirect/>
    </navigation-case>
</navigation-rule>

With JSF 2.0, the rule changes the URL to /login.xhtml when redirecting (where it was left as /login with 1.2) and it was caught by the security setting in my web.xml that prevents users from viewing raw templates.

<security-constraint>
    <web-resource-collection>
        <web-resource-name>Protect XHTML Templates</web-resource-name>
        <url-pattern>*.xhtml</url-pattern>
    </web-resource-collection>
    <auth-constraint/>
</security-constraint>

To solve this issue, I had to make a couple of changes:

  • Comment out the security-constraint in web.xml and move it to Spring Security's security.xml file.
    <intercept-url pattern="/**/*.xhtml" access="ROLE_NOBODY"/>
    
  • Add a rule to urlrewrite.xml that redirects back to login (since login.xhtml doesn't exist and I'm using extensionless URLs).
    <rule match-type="regex">
        <from>^/login.xhtml$</from>
        <to type="redirect">%{context-path}/login</to>
    </rule>
    

After getting the Password Hint feature passing in the browser, I tried running the integration tests (powered by Canoo WebTest). The Password Hint test kept failing with the following error:

[ERROR] /Users/mraible/dev/appfuse/web/jsf/src/test/resources/web-tests.xml:51: JavaScript error loading
page http://localhost:9876/appfuse-jsf-2.1.0-SNAPSHOT/passwordHint?username=admin: syntax error (http://
localhost:9876/appfuse-jsf-2.1.0-SNAPSHOT/javax.faces.resource/oamSubmit.js.jsf?ln=org.apache.myfaces#122)

Figuring this was caused by my hack to submit the form when the page was loaded, I turned to Pretty Faces, which allows you to call a method directly from a URL. After adding the Pretty Faces dependencies to my pom.xml, I created a src/main/webapp/WEB-INF/pretty-config.xml file with the following XML:

<url-mapping>
    <pattern value="/editProfile"/>
    <view-id value="/userForm.jsf"/>
    <action>#{userForm.edit}</action>
</url-mapping>

<url-mapping>
    <pattern value="/passwordHint/#{username}"/>
    <view-id value="/passwordHint.jsf"/>
    <action>#{passwordHint.execute}</action>
</url-mapping>

This allowed me to remove both editProfile.xhtml and passwordHint.xhtml, both of which simply auto-submitted forms.

At this point, I figured I'd be good to go and ran my integration tests again. The first thing I discovered was that ".jsf" was being tacked onto my pretty URL, most likely by the UrlRewriteFilter. Adding the following to my PasswordHint.java class solved this.

if (username.endsWith(".jsf")) {
    username = username.substring(0, username.indexOf(".jsf"));
}

The next thing was a cryptic error that took me a while to figure out.

DEBUG [1152467051@qtp-144702232-0] PasswordHint.execute(38) | Processing Password Hint...
2011-03-05 05:48:52.471:WARN::/passwordHint/admin
com.ocpsoft.pretty.PrettyException: Exception occurred while processing <:#{passwordHint.execute}> null
        at com.ocpsoft.pretty.faces.beans.ActionExecutor.executeActions(ActionExecutor.java:71)
        at com.ocpsoft.pretty.faces.event.PrettyPhaseListener.processEvent(PrettyPhaseListener.java:214)
        at com.ocpsoft.pretty.faces.event.PrettyPhaseListener.afterPhase(PrettyPhaseListener.java:108)
        at org.apache.myfaces.lifecycle.PhaseListenerManager.informPhaseListenersAfter(PhaseListenerManager.java:111)
        at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:185)
        at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)

Digging into the bowels of MyFaces, I discovered a class was looking for a viewId with an extension and no view-id was being set. Adding the following to the top of my execute() method solved this.

getFacesContext().getViewRoot().setViewId("/passwordHint.xhtml");

After making this change, all AppFuse's integration tests are passing and the upgrade seems complete. The only other issues I encountered were logging-related. The first is an error about Tomahawk that doesn't seem to affect anything.

Mar 5, 2011 6:44:01 AM com.sun.facelets.compiler.TagLibraryConfig loadImplicit
SEVERE: Error Loading Library: jar:file:/Users/mraible/.m2/repository/org/apache/myfaces/tomahawk/tomahawk20/1.1.10/tomahawk20-1.1.10.jar!/META-INF/tomahawk.taglib.xml
java.io.IOException: Error parsing [jar:file:/Users/mraible/.m2/repository/org/apache/myfaces/tomahawk/tomahawk20/1.1.10/tomahawk20-1.1.10.jar!/META-INF/tomahawk.taglib.xml]: 
        at com.sun.facelets.compiler.TagLibraryConfig.create(TagLibraryConfig.java:410)
        at com.sun.facelets.compiler.TagLibraryConfig.loadImplicit(TagLibraryConfig.java:431)
        at com.sun.facelets.compiler.Compiler.initialize(Compiler.java:87)
        at com.sun.facelets.compiler.Compiler.compile(Compiler.java:104)

The second is excessive logging from MyFaces. As far as I can tell, this is because MyFaces switched to java.util.logging instead of commons logging. With all the frameworks that AppFuse leverages, I think it has all the logging frameworks in its classpath now. I was hoping to fix this by posting a message to the mailing list, but haven't received a reply yet.

[WARNING] [talledLocalContainer] Mar 5, 2011 6:50:25 AM org.apache.myfaces.config.annotation.TomcatAnnotationLifecycleProvider newInstance
[WARNING] [talledLocalContainer] INFO: Creating instance of org.appfuse.webapp.action.BasePage
[WARNING] [talledLocalContainer] Mar 5, 2011 6:50:25 AM org.apache.myfaces.config.annotation.TomcatAnnotationLifecycleProvider destroyInstance
[WARNING] [talledLocalContainer] INFO: Destroy instance of org.appfuse.webapp.action.BasePage

After successfully upgrading AppFuse, I turned to AppFuse Light, where things were much easier.

Now that AppFuse uses JSF 2, I hope to start leveraging some of its new features. If you're yearning to get started with them today, I invite you to grab the source and start integrating them yourself.

Posted in Java at Mar 07 2011, 01:24:53 PM MST 3 Comments

Implementing Extensionless URLs with Tapestry, Spring MVC, Struts 2 and JSF

For the past couple of weeks, I've spent several evening hours implementing extensionless URLs in AppFuse. I've been wanting to do this ever since I wrote about how to do it a few years ago. This article details my experience and will hopefully help others implement this feature in their webapps.

First of all, I used the UrlRewriteFilter, one of my favorite Java open source projects. Then I followed a pattern I found in Spring's "mvc-basic" sample app from MVC Simplifications in Spring 3.0. The app has since changed (because SpringSource integrated UrlRewriteFilter-type functionality in Spring MVC), but the pattern was basically path-matching instead of extension-mapping. That is, the "dispatcher" for the web framework was mapped to /app/* instead of *.html.

Prior to the move to extensionless URLs, AppFuse used *.html for its mapping and this seemed to cause users problems when they wanted to serve up static HTML files. To begin with, I removed all extensions from URLs in tests (Canoo WebTest is used for testing the UI). I also did this for any links in the view pages and redirects in the Java code. This provided a decent foundation to verify my changes worked. Below are details about each framework I did this for, starting with the one that was easiest and moving to hardest.

Tapestry 5
Tapestry was by far the easiest to integrate extensionless URLs into. This is because it's a native feature of the framework and was already integrated as part of Serge Eby's Tapestry 5 implementation. In the end, the only things I had to do where 1) add a couple entries for CXF (mapped to /services/*) and DWR (/dwr/*) to my urlrewrite.xml and 2) change the UrlRewriteFilter so it was only mapped to REQUEST instead of both REQUEST and FORWARD. Below are the mappings I added for CXF and DWR.

<urlrewrite default-match-type="wildcard">
    ...
    <rule>
        <from>/dwr/**</from>
        <to>/dwr/$1</to>
    </rule>
    <rule>
        <from>/services/**</from>
        <to>/services/$1</to>
    </rule>
</urlrewrite>

Spring MVC
I had a fair amount of experience with Spring MVC and extensionless URLs. Both the Spring MVC applications we developed last year at Time Warner Cable used them. To change from a *.html mapping to /app/* was pretty easy and involved removing more code than I added. Previously, I had a StaticFilter that looked for HTML files and if it didn't find them, it dispatched to Spring's DispatcherServlet. I was able to remove this class and make the web.xml file quite a bit cleaner.

To make UrlRewriteFilter and Spring Security play well together, I had to move the securityFilter so it came after the rewriteFilter and add an INCLUDE dispatcher so included JSPs would have a security context available to them.

<filter-mapping>
    <filter-name>rewriteFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>securityFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>INCLUDE</dispatcher>
</filter-mapping>

The only other things I had to change were security.xml and dispatcher-servlet.xml to remove the .html extensions. The urlrewrite.xml file was fairly straightforward. I used the following at the bottom as a catch-all for dispatching to Spring MVC.

<rule>
    <from>/**</from>
    <to>/app/$1</to>
</rule>
<outbound-rule>
    <from>/app/**</from>
    <to>/$1</to>
</outbound-rule>

Then I added a number of other rules for j_security_check, DWR, CXF and static assets (/images, /scripts, /styles, /favicon.ico). You can view the current urlrewrite.xml in FishEye. The only major issue I ran into was that Spring Security recorded protected URLs as /app/URL so I had to add a rule to redirect when this happened after logging in.

<rule>
    <from>/app/**</from>
    <to last="true" type="redirect">%{context-path}/$1</to>
</rule>

Struts 2
Using extensionless URLs with Struts 2 is likely pretty easy thanks to the Convention Plugin. Even though this plugin is included in AppFuse, it's not configured with the proper constants and I have struts.convention.action.disableScanning=true in struts.xml. It looks like I had to do this when I upgraded from Struts 2.0.x to Struts 2.1.6. It's true AppFuse's Struts 2 support could use a bit of love to be aligned with Struts 2's recommended practices, but I didn't want to spend the time doing it as part of this exercise.

With Struts 2, I tried the path-mapping like I did with Spring MVC, but ran into issues. Instead, I opted to use an ".action" extension by changing struts.action.extension from "html" to "action," in struts.xml. Then I had to do a bunch of filter re-ordering and dispatcher changes. Before, with a .html extension, I had all filters mapped to /* and in the following order.

Filter NameDispatchers
securityFilter request
rewriteFilter request, forward
struts-prepare request
sitemesh request, forward, include
staticFilter request, forward
struts request

Similar to Spring MVC, I had to remove the rewriteFilter in front of the securityFilter and I was able to remove the staticFilter. I also had to map the struts filter to *.action instead of /* to stop Struts from trying to catch static asset and DWR/CXF requests. Below is the order of filters and their dispatchers that seems to work best.

Filter NameDispatchers
rewriteFilter request
securityFilter request, forward, include
struts-prepare request, forward
sitemesh request, forward, include
struts forward

From there, it was a matter of modifying urlrewrite.xml to have the following catch-all and rules for static assets, j_security_check and DWR/CXF.

<rule match-type="regex">
    <from>^([^?]*)/([^?/\.]+)(\?.*)?$</from>
    <to last="true">$1/$2.action$3</to>
</rule>
<outbound-rule match-type="regex">
    <from>^(.*)\.action(\?.*)?$</from>
    <to last="false">$1$2</to>
</outbound-rule>

JSF
JSF was by far the most difficult to get extensionless URLs working with. I'm not convinced it's impossible, but I spent a several hours over a few days and was unsuccessful in completely removing them. I was able to make things work so I could request pages without an extension, but found when clicking buttons and links, the extension would often show up in the URL. I'm also still using JSF 1.2, so it's possible that upgrading to 2.0 would solve many of the issues I encountered.

For the time being, I've changed my FacesServlet mapping from *.html to *.jsf. As with Struts, I had issues when I tried to map it to /app/*. Other changes include changing the order of dispatchers and filters, the good ol' catch-all in urlrewrite.xml and modifying security.xml. For some reason, I wasn't able to get file upload working without adding an exception to the outbound-rule.

<rule match-type="regex">
    <from>^([^?]*)/([^?/\.]+)(\?.*)?$</from>
    <to last="true">$1/$2.jsf</to>
</rule>
<outbound-rule match-type="regex">
  <!-- TODO: Figure out how to make file upload work w/o using *.jsf -->
    <condition type="path-info">selectFile</condition>
    <from>^(.*)\.jsf(\?.*)?$</from>
    <to last="false">$1$2</to>
</outbound-rule>

I also spent a couple hours trying to get Pretty Faces to work. I wrote about my issues on the forums. I tried writing a custom Processor to strip the extension, but found that I'd get into an infinite loop where the processor kept getting called. To workaround this, I tried using Spring's RequestContextHolder to ensure the processor only got invoked once, but that proved fruitless. Finally, I tried inbound and outbound custom processors, but failed to get those working. The final thing I tried was url-mappings for each page in pretty-config.xml.

<url-mapping>
  <pattern value="/admin/users"/>
  <view-id value="/admin/users.jsf"/>
</url-mapping>
<url-mapping>
  <pattern value="/mainMenu"/>
  <view-id value="/mainMenu.jsf"/>
</url-mapping>

The issue with doing this was that some of the navigation rules in my faces-config.xml stopped working. I didn't spend much time trying to diagnose the problem because I didn't like having to add an entry for each page in the application. The one nice thing about Pretty Faces is it did allow me to do things like the following, which I formerly did with a form that auto-submitted when the page loaded.

<url-mapping>
  <pattern value="/passwordHint/#{username}"/>
  <view-id value="/passwordHint.jsf"/>
  <action>#{passwordHint.execute}</action>
</url-mapping>

Conclusion
My journey implementing extensionless URLs was an interesting one, and I solidified my knowledge about ordering of filters, dispatchers and the UrlRewriteFilter. I still think I have more to learn about properly implementing extensionless URLs in Struts 2 and JSF and I hope to do that in the near future. I believe Struts' Convention Plugin will help me and JSF 2 + Pretty Faces will hopefully work nicely too. Of course, it'd be great if all Java Web Frameworks had an easy mechanism for producing and consuming extensionless URLs. In the meantime, thank goodness for the UrlRewriteFilter.

If you'd like to try AppFuse and its shiny new URLs, see the QuickStart Guide and choose the 2.1.0-SNAPSHOT version.

Posted in Java at Feb 10 2011, 04:53:27 PM MST 10 Comments

How I Calculated Ratings for My JVM Web Frameworks Comparison

When I re-wrote my Comparing JVM Web Frameworks presentation from scratch, I decided to add a matrix that allows you to rate a framework based on 20 different criteria. The reason I did this was because I'd used this method when choosing an Ajax framework for Evite last year. The matrix seemed to work well for selecting the top 5 frameworks, but it also inspired a lot of discussion in the community that my ratings were wrong.

I expected this, as I certainly don't know every framework as well as I'd like. The mistake I made was asking for the community to provide feedback on my ratings without describing how I arrived at them. From Peter Thomas's blog:

What you are doing is adjusting ratings based on who in the community shouts the loudest. I can't help saying that this approach comes across as highly arrogant and condescending, you seem to expect framework developers and proponents to rush over and fawn over you to get better ratings, like waiters in a restaurant trying to impress a food-critic for Michelin stars.

I apologize for giving this impression. It certainly wasn't my intent. By having simple numbers (1.0 == framework does well, 0.5 == framework is OK and 0 == framework not good at criteria) with no rationalization, I can see how the matrix can be interpreted as useless (or to put it bluntly, as something you should wipe your ass with). I don't blame folks for getting angry.

For my Rich Web Experience presentation, I documented why I gave each framework the rating I did. Hopefully this will allow folks to critique my ratings more constructively and I can make the numbers more accurate. You can view this document below or on Google Docs.

In the end, what I was hoping to do with this matrix was to simply highlight a technique for choosing a web framework. Furthermore, I think adding a "weight" to each criteria is important because things like books often aren't as important as REST support. To show how this might be done, I added a second sheet to the matrix and made up some weighting numbers. I'd expect anyone that wants to use this to downloaded the matrix, verify the ratings are accurate for your beliefs and weight the criteria accordingly.

Of course, as I and many others have said, the best way to choose a web framework is to try them yourself. I emphasized this at the end of my presentation with the following two slides.

Slide #77 from Comparing JVM Web Frameworks Talk at RWX2010

Slide #76 from Comparing JVM Web Frameworks Talk at RWX2010

Posted in Java at Dec 06 2010, 11:55:18 AM MST 10 Comments

My Comparing JVM Web Frameworks Presentation from Devoxx 2010

This week, I've been having a great time in Antwerp, Belgium at the Devoxx Conference. This morning, I had the pleasure of delivering my Comparing JVM Web Frameworks talk. I thoroughly enjoyed giving this presentation, especially to such a large audience. You can view the presentation below (if you have Flash installed) or download it here.

Unlike previous years, I chose to come up with a spreadsheet matrix that shows why I chose the 5 I did. This spreadsheet and rankings given to each framework are likely to be debated, as I don't know all the frameworks as well as I'd like to. Also, the missing column on this spreadsheet is a "weighting" column where you can prioritize certain criteria like I've done in the past when Comparing Ajax Frameworks. If you believe there are incorrect numbers, please let me know and I'll try to get those fixed before I do this talk again at The Rich Web Experience.

One thing that doesn't come across in this presentation is that I believe anyone can use this matrix, and weightings, to make any of these frameworks come out on top. I also believe web frameworks are like spaghetti sauce in The Ketchup Conundrum. That is, the only way to make more happy spaghetti sauce lovers was to make more types of spaghetti sauce. You can read more about this in my There is no "best" web framework article.

Update: If you disagree with the various ratings I gave to web frameworks in this presentation, please provide your opinions by filling out this survey. Thanks to Sebastien Arbogast for setting this up.

Update: Sebastien has posted his survey results at JVM Web Framework Survey, First Results.

Update 12/6: A video of this presentation is now available on Parleys.com.

P.S. My current gig is ending in mid-December. If you're looking for a UI Architect with a passion for open source frameworks, please let me know.

Posted in Java at Nov 18 2010, 05:23:10 AM MST 39 Comments

AppFuse 2.1 Milestone 2 Released

I'm pleased to announce the 2nd milestone release of AppFuse 2.1. This release includes upgrades to all dependencies to bring them up-to-date with their latest releases. Most notable are Spring 3 and Struts 2.1. This release fixes many issues with archetypes and contains many improvements to support Maven 3. For more details on specific changes see the 2.1.0 M2 release notes.

What is AppFuse?
AppFuse is an open source project and application that uses open source frameworks to help you develop Web applications quickly and efficiently. It was originally developed to eliminate the ramp-up time when building new web applications. 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. If you use JRebel with AppFuse, you can achieve zero-turnaround in your project and develop features without restarting the server.

Release Details
Archetypes now include all the source for the web modules so using jetty:run and your IDE will work much smoother now. The backend is still embedded in JARs, enabling you to choose with persistence framework (Hibernate, iBATIS or JPA) you'd like to use. If you want to modify the source for that, add the core classes to your project or run "appfuse:full-source".

AppFuse comes in a number of different flavors. It offers "light", "basic" and "modular" and archetypes. Light archetypes use an embedded H2 database and contain a simple CRUD example. In the final 2.1.0 release, the light archetypes will allow code generation like the basic and modular archetypes. Basic archetypes have web services using CXF, authentication from Spring Security and features including signup, login, file upload and CSS theming. Modular archetypes are similar to basic archetypes, except they have multiple modules which allows you to separate your services from your web project.

AppFuse provides archetypes for JSF, Spring MVC, Struts 2 and Tapestry 5. The light archetypes are available for these frameworks, as well as for Spring MVC + FreeMarker, Stripes and Wicket.

Please note that this release does not contain updates to the documentation. Code generation will work, but it's likely that some content in the tutorials won't match. For example, you can use annotations (vs. XML) for Spring MVC and Tapestry is a whole new framework. I'll be working on documentation over the next several weeks in preparation for the 2.1 final release.

For information on creating a new project, please see the QuickStart Guide.

If you have questions about AppFuse, please read the FAQ or join the user mailing list. If you find bugs, please create an issue in JIRA.

Thanks to everyone for their help contributing patches, writing documentation and participating on the mailing lists.

Posted in Java at Nov 15 2010, 03:28:57 PM MST 2 Comments

AppFuse 2.1 Milestone 1 Released

The AppFuse Team is pleased to announce the first milestone release of AppFuse 2.1. This release includes upgrades to all dependencies to bring them up-to-date with their latest releases. Most notable are Hibernate, Spring and Tapestry 5.

What is AppFuse?
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.

Release Details
Archetypes now include all the source for the web modules so using jetty:run and your IDE will work much smoother now. The backend is still embedded in JARs, enabling you to choose which persistence framework (Hibernate, iBATIS or JPA) you'd like to use. If you want to modify the source for that, add the core classes to your project or run appfuse:full-source.

In addition, AppFuse Light has been converted to Maven and has archetypes available. AppFuse provides archetypes for JSF, Spring MVC, Struts 2 and Tapestry 5. The light archetypes are available for these frameworks, as well as for Spring MVC + FreeMarker, Stripes and Wicket.

Other notable improvements:

Please note that this release does not contain updates to the documentation. Code generation will work, but it's likely that some content in the tutorials won't match. For example, you can use annotations (vs. XML) for dependency injection and Tapestry is a whole new framework. I'll be working on documentation over the next several weeks in preparation for Milestone 2.

AppFuse is available as several Maven archetypes. For information on creating a new project, please see the QuickStart Guide.

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

The 2.x 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 have questions about AppFuse, please read the FAQ or join the user mailing list. If you find bugs, please create an issue in JIRA.

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

Posted in Java at Nov 19 2009, 07:16:36 AM MST 8 Comments