Raible Designs

Got RSS Bandwidth Issues?

I got an interesting e-mail the other day from my.rsscache.com. It appears to be a caching service for your RSS feeds. I definitely have bandwidth issues, but I'm not too concerned because Google Ads pay for my hosting costs. This looks like a valuable service, and it's cool they have a cached version of my RSS feed, but I'm wondering what the catch is? There has to be some sort of catch. Are they just trying to get weblogs to signup, and advertise their service - and then hope to get big corporate players that will pay?

Tapestry Tutorial Roundup

I'm going to start integrating Tapestry into AppFuse in the next few weeks. There's nothing like a good set of tutorials to help this process along. Here's a list of current tutorials I found - let me know if you know of others:

• Introduction to Jakarta Tapestry
• Getting Started with Tapestry and Part II: Improving the Currency Converter
• Creating a Tapestry CRUD application

There also seems to be an up-to-date list of Tapestry Resources on Java201.com. I've started reading Tapestry in Action, so hopefully that will speed things up. I've made it to page 100 and I'm afraid I won't make it much further. I need to "just do it" more than I need to learn how to do it. I've often found that I learn a lot more after diving into the code and trying to do something and go back to reading when I start banging my head against the wall.

Integrating Tapestry into AppFuse shouldn't be that hard. I've already done it with the MyUsers application from Spring Live. Therefore, the Tapestry+Spring stuff will be easy. The only hard part, as far as I can tell, is going to be integrating Friendly URLs. Anyone got a patch for Tapestry 3.0.1?

Comparing Web Frameworks: Presentation Outline

My Comparing Web Frameworks outline is due to the ApacheCon Planners today. I spent a couple of hours putting it together this morning and I'm mostly done. In reality, I know that I won't cover the things that everyone wants to know. In an ideal world, I could simply target the presentation towards people like me: they know Struts but want to learn more about the other frameworks. Before diving in, they want to know some things to watch out for.

The problem with doing that is writing for people like me sometimes backfires. I'd like to make it an advanced presentation, but I'm not an authority on all 5 frameworks - so that seems a bit far fetched. However, if I could add Tapestry and JSF support to AppFuse in the next two weeks - I'd have a lot more experience to refer to. But that ain't gonna happen - the first update chapter for Spring Live is due next week. OK, enough rambling - here's the slide titles I've come up with. So far, it's 22 slides and shouldn't grow any since it's supposed to be finalized when I submit it.

• Who is Matt Raible? My background, open source involvement, etc. Trying to give myself some credibility.
• Framework Experience: Long time Struts user, used Spring since end of last year, developed apps with other three this summer. AppFuse supports Struts, Spring MVC and WebWork; Tapestry and JSF coming before end of year.
• Meet the Candidates
  • Struts: Pros and Cons. Pretty much a standard, lots of examples, HTML tag library kicks ass. ActionForms kinda suck, can't unit test (only StrutsTestCase integration tests), Mailing list is swamped.
  • Spring MVC: Nice lifecyle (for overriding binding, validation, etc.) integrates with many view options seamlessly, IoC for easy testability. Not widely used, requires lots of code in JSPs, almost too flexible (no parent controller for SimpleFormController and Controller).
  • WebWork: Simple architecture, tag library easy to customize, interceptors are pretty slick. Documentation only recently written, few examples, client-side validation needs work.
  • Tapestry: Very productive once you learn it, templates are HTML (great for designers), healthy project. Documentation very conceptual, rather than pragmatic (lots of "read the book"). Steep learning curve, few examples. Impossible to test - page classes are abstract.
  • JSF: J2EE standard (lots of demand and jobs), fast and easy to develop with, rich navigation framework. Tag soup for JSPs, a bit immature (doesn't come with everything), no single source for implementation.
• Controllers and Views: Show controllers for all 5 frameworks and template page (JSP/HTML) for forms. Give URL to download sample apps.
• List Screens: How easy is it to integrate a sortable/pageable list of data? Struts, Spring and WebWork can use tag libraries like the display tag, value list or data grid. Tapesty has contrib:Table. JSF has dataTable component that requires custom logic for sorting (let me know if this has changed).
• Bookmarking and URLs: Struts, Spring and WebWork give you full URL control. Tapestry has ugly URLs. JSF does a POST for everything. Conclusion: first 3 play nicely with container-managed authentication. Tapestry doesn't (although there's a patch for pretty URLs). JSF is not friendly to bookmarking.
• Validation: Struts and Spring MVC can use Commons Validation - a mature solution. I've heard it's architecture is ugly, but who cares - it works! WebWork uses OGNL which allows powerful expressions. Client-side support is new and maturing. Tapestry has robust validation w/ good messages out-of-the-box. JSF has ugly default error messages, but is the easiest to configure.
• Testability: Struts you can use StrutsTestCase, which requires web.xml and struts-config.xml. WebWork and Spring allow easy testing with Mocks. Spring has a spring-mock.jar that can be used for mocking the Servlet API with any framework (it's not Spring-specific). Tapestry is impossible to test because page classes are abstract. The argument I've hard is "you don't need to test them b/c they're so simple." JSF page classes can be easily tested and actually look a lot like WebWork Actions (except they don't extend anything).
• Success Messages: The easiest way to solve the duplicate-post problem is to redirect after doing a POST. Struts is the only framework that allows for success messages to live through a redirect. It's fairly easy to get i18n messages in a Struts Action. Spring has nothing "built-in" for success messages. Long classnames / method arguments make it kinda clunky to get messages. WebWork has the cleanest way to get messages using a simple "getText()" method. Both require a custom solution to make your messages live through a redirect. Tapestry requires you to throw an exception to redirect and it still doesn't redirect (I haven't solved the duplicate post problem with Tapestry). JSF requires lots of code to get a ResourceBundle, but you could use Spring's IoC to inject a "messageSource" bean, making it a lot easier. JSF requires a custom solution for messages to live past a redirect.
• Spring Integration: Supported by all, sample apps have examples (quick slide).
• Internationalization: JSTL's <fmt:message> tag makes it easy in all JSP-supporting frameworks. Too bad there's not a standard for getting bundles in controllers and setting messages. Struts, Spring and JSF encourage you to use one ResourceBundle for all messages while WebWork and Tapestry encourage separate files for each page/action. This strategy is probably better for large teams.
• Page Decoration: I used to be a huge advocate of Tiles (using it since August 2001). SiteMesh is much easier to setup and use. Tiles can be used in Struts, Spring MVC and JSF. SiteMesh can be used with all 5 frameworks. In fact, the sample app uses the same SiteMesh setup for all w/o changing a thing. SiteMesh requires no maintenance, Tiles requires you add entries to tiles-config.xml whenever you add a new page.
• Tools: Struts has lots of tools available for it and even frameworks built on top of it (i.e. Beehive's NetUI/PageFlow). Spring has Spring IDE which is really just an XML tool for validating your bean and their relationships. WebWork has none (that've been released), but it is on the roadmap. Tapestry has Spindle, which is great for code-level programmers. It doesn't do drag-n-drop, but it does validate relationships between files. JSF has lots - but all of them cost money and tend to hook into proprietary app servers.
• Business/Marketing: Struts has lots of jobs and is well-known in the industry. A lot of enterprise applications are based on it. Spring is getting more press, but mostly because of the framework's other features. Knowing the rest of Spring is more valuable than Spring MVC. WebWork is gaining ground, but it's still virtually unheard of on job boards. If you do get gigs using WebWork, it's likely word-of-mouth and you'll probably be working with some pretty smart people. Often used with Spring and Hibernate. Tapestry needs more marketing - no one has heard of it, hence no jobs exist for it. JSF is quickly becoming the most popular. Want to stay employed? Learn JSF. The best reason: so you can back up your arguments on why you do/don't like it.
  
  Dice Job Count: Struts (1006), Spring (15 - not a very good name for searching, used "spring framework"), WebWork (14), Tapestry (9), JSF (147).
  
  
• My Opinion: You have to come to the conference for that . Slides should be posted following my presentation.
• Resources: Link and such for downloads, frameworks and tools mentioned.

Comments, suggestions, like it/hate it? Let me know. I expect to send this in in a few hours - so you'd better be quick!

I don't hate JSF

I'm still amazed by all the traffic and comments received by my experience with JSF. In some cases it feels like I insulted some of these guys wives or something. Here's some good quotes from the comments:

The less than positive experience is because Matt wants to write an app while asking a million questions all over mailing lists and not investing the time to learn.

I think you're too in love with struts to have a clear sight on what's going on.

Pick your poison and stop bad-mouthing others because you don't get.

I admit that I was a bit harsh on JSF in my post. Here's why. I developed 5 simple apps this summer, all doing the same thing with different frameworks: Struts, Spring MVC, WebWork, Tapestry and JSF. All of them hooked into the same backend, which was Spring+Hibernate. I had a learning curve to overcome with WebWork, Tapestry and JSF. I already knew Struts and Spring MVC, so those versions where easy to develop with. Of the three (WebWork, Tapestry and JSF), I was able to complete the JSF version the fastest. It took me a 1 1/2 days for WebWork, 3 days for Tapestry and 1 day for JSF. Or so I thought.

The JSF app was pretty close to being finished, but I was missing one thing - a sortable/pageable table. And I hadn't written the test for my page classes yet. This was Wednesday. I made a post late that night on how much I liked the JSF-Spring integration library. If you'll notice in this post, I mentioned that I got the displaytag to work too (almost). I found that I had to use an empty tag to pull the list of users from my page bean into the request, and then the displaytag could render the list. This was almost perfect, but the <h:commandLink> didn't work, so I had no way of editing a record from the table.

At this point, it all started to break down - and my frustration began. I was sooo close to completing this application and so far (even with the minor snags I'd hit) it was the easiest one to develop. Juergen left a comment stating that Spring's core now had a DelegatingVariableResolver in its core. So I figured I'd make my application more "pure" and use that instead of the JSF-Spring integration library. This was my first mistake. The DelegatingVariableResolver from Spring didn't work with Sun's RI and only worked with MyFaces. I figured it wouldn't be hard to switch (JSF is a standard, right?) - so I went to it the next day. I'd also heard that MyFaces had a sortable/pageable dataGrid - so the switch seemed like a good idea.

The first bump in the road was that while the DelegateVariableResolver worked, MyFaces reported an error. The Spring guys blamed MyFaces and MyFaces blamed Spring. Result: it's a bug that no one will fix. I spent a couple hours being a good open-source citizen by 1) trying to fix it and 2) reporting it. The second bumb in the road was that I had to change a few things that worked in the RI but didn't work in MyFaces (I forget what now). However, this wasn't so bad since it also fixed a couple of issues.

Next I tried to use MyFace's <x:dataTable> to replace the display tag. Since it had a sortHeader component, I figured this would be easy. It turns out this component requires you to implement custom logic in your page bean. Things might've changed since July, but I doubt it. Lastly, aftering getting everything to work, I went to work on writing a jWebUnit test to test it all. While doing so, I found that it was almost impossible to test my edit screen. With other frameworks, I could specify a URL with a record id and then proceed to change form fields and push buttons. With JSF, there was no easy way to determine the URL. The rendered UI used heavy JavaScript and when you clicked on a link in the dataTable, this called a JavaScript function. I have no problems with JavaScript and I think it's a great technology. However, the current UI testing frameworks I use (jWebUnit and Canoo WebTest) use the Rhino JavaScript library (js.jar) and it sucks at JavaScript. It reports errors where there are no errors - and hence, I tend to exclude the JAR and disable JavaScript support in my tests. If there was better JavaScript support in these testing frameworks - I'd likely have to problems with JSF's "I post for every link" mantra.

In most of my development life, I've most often been a framework user rather than a developer. This means that if I find problems, I don't extend the framework - I look for other solutions. Call me whatever you like, but I'm just trying to get my job done and the project completed. I don't want to mess with the internals of a framework to make that happen. With JSF (and Tapestry too), you have to be more of a framework developer. You have to be willing to create your own components. These frameworks are designed as component frameworks and they want you to extend them. That's one of the major points of their architecture.

So here I am again, posting about JSF - which will undoubtably get an incredible amount of hits just because it has "JSF" in the title. Why? Because you can't ignore JSF. Even if you don't want to develop with it - there's going to be tons of jobs that require JSF in the near future. In fact, there are already quite a few. Surprisingly enough, in my job search last month, I has a more opportunities for JSF (and WebWork suprisingly enough) than Struts. Finding a Tapestry gig - good luck. Of course, I'm a consultant, not an employee - so I don't often don't get to choose frameworks for companies.

I think JSF is an immature technology that will rapidly mature. I hope it does b/c it was fairly easy to develop with - there were merely some minor bugs in the two implementations. These can be fixed. In reality, I think we should all quit bashing on JSF and jump in to try and make it better. Rather than complaining, let's try to help.

I've done my part and applied to be on the JSF Expert Group. They probably won't let me in though - everyone seems to link I hate JSF. If I had my way, I'd scrap the sucker and make Tapestry the JSF standard.

Comparing the Big 5 Web Frameworks

My session at ApacheCon is titled Comparing Web Frameworks: Struts, Spring MVC, WebWork, Tapestry & JSF. I have to turn in my presentation by Friday. The purpose of this post is to get your feedback and see what you'd like to see in such a talk. Here's the abstract:

This session is designed to explore the popular Java web frameworks. It will briefly explain how each one works and the strengths and weaknesses of each. Tips, tricks and gotcha's will be plentiful. A simple web application will be dissected and the different options will be compared. Lastly, it will provide attendees with a sample app they can download that has options to use any of the frameworks described.

The simple webapp is MyUsers from Spring Live. As part of my gig with Open Logic this summer, I wrote a number of sample apps using Equinox. Among these where 1) a Mavenized version, 2) a Tapestry version, 3) a JSF version, and 4) WebWork version. The Struts and Spring MVC versions were already done as part of the book. They agreed to let me use the code and knowledge from that experience. This is all to say it shouldn't be too hard to create the sample app for this talk.

The hard part is going to be talking about things that developers care about. In my post on JSF a while back, I noted the things I typically want in my webapps. The following topics might make good points of discussion.

• A sortable/pageable list of data. It's possible, but you have to add special sorting logic for each class. JSP already has this with the display tag - I'd simply like to be able to use it in JSF.
• Bookmarkability. Container managed authentication gives us a great way to offer users the ability to bookmark pages. If everything is a POST with JSF, we lose this ability. Sure there's the HTMLOutputLink, but if we can't invoke actions, what good is it?
• Clean and easy to read validation messages. The validation messages in both MyFaces and Sun's RI are not something you'd deliver to customers. What's wrong with making clean messages out-of-the-box? Tapestry seems to have no problems doing this. All the other MVC frameworks make you specify your own - which is fine with me.
• Easy cancelling and multi-button form handling. JSF does this well - better than the rest I'd say.
• Easy testability. Because of the plethora of JavaScript, JSF apps are difficult to test with tools like jWebUnit and Canoo's WebTest. Don't get me wrong, I love JavaScript - but an application should be able to be tested w/o it.
• Success Messages. JSF does success messages OK - it's a pity it's not easier to get a resource bundle and it's a shame that you can't escape HTML in the <h:messages> tag. This seems like an oversight to me.

I could do a number of slides and show how each framework handles the above situations. Other topics that would be worthwhile would be:

• Model in View - can you use your model objects to back forms or do you have to use something like ActionForms?
• Spring Integration - all of them have this. This would merely be a discussion on how its handled.
• Validation - how robust and/or extensible is it? How hard is it to do chained validation? What about client-side validation? Is the client-side stuff immature like WebWork's?
• Internationalization - how is it done and how hard is it to get messages in your classes? JSF sucks at this.
• The Duplicate Post Problem - how does it handle duplicate posts. Not the "push the submit button twice" but the "hit refresh after saving" kind. Tapestry fails this test.
• Page Decoration - SiteMesh can be used for all frameworks, Tiles for some. Discuss how much easier it is to use SiteMesh.
• Tools - since some frameworks have tools to help ease there development and others don't.
• Business/Marketing - how well known is the framework and will your skills be marketable if you learn it? JSF and Struts are in high demand. Tapestry is virtually unheard of. WebWork is for the evil few (heh!) and Spring MVC is the new kid on the block.

Whaddya think - what is so special about your framework that'll make it look better in my talk? What are the things that suck that I can bash on? If you're a committer on one of these frameworks - are you going to be at ApacheCon? I'd love to have some folks defend their projects after I'm done ripping on them. If I don't rip on yours, then you can bask in all its glory.

If you live in Denver, I'll be delivering this presentation at DJUG's Architecture SIG on November 3rd.

Estimating Projects

Martin Fowler has a good post on the Fixed Scope Mirage.

Many companies like the idea of writing a contract that fixes scope and price because they think it lowers their risk. The mirage says that their financial obligation is fixed at the price of the deal. If they don't get satisfactory software, then it won't cost them.

I see this often when looking for new projects. The potential client has a project they want done, and they want it done in X weeks/months. Why? Because they're willing to pay X dollars for the software and their next door neighbor (whose in IT) did an estimate for them while they were drinking beers the other day. I've learned my leason with these clients - run! Any client that estimates how long it'll take you to do something is going to be a nightmare to work for. Furthermore, if you get the gig - you've likely told them that you could do it in their timeframe.

Even worse are clients that want you to do a 1-2 week project. These are a nightmare because they tend to want lots of functionality, but don't want to pay for it - hence the 2 week project. From my experience, I've learned to only take clients that allow you to do the estimating and have projects that are a month or longer.

Resin slower than Tomcat, fails the AppFuse Test

As part of AppFuse 1.6, I was hoping to supply the option to use Resin instead of Tomcat. In reality, hardly anyone has asked for this on the mailing list - but since so many folks say that "Resin is better" - I figured I'd give it a whirl. I hate to be the guy that spoils all the Resin users mantra, but it seems like Tomcat is the better server. Why? Speed, compliance and shit works. Here are some things I found:

• Server startup time when AppFuse is only app installed (deleted work directories before starting):
  • Resin: 25 seconds
  • Tomcat: 14 seconds
  I also found that Resin loads my StartupListener twice b/c it's defined in web.xml and XDoclet puts it in the generated TLD. I think the best solution is to add a flag to XDoclet to allow you to exclude listeners from the TLD when it's generated. I commented out the entry in web.xml for this test.
• Running "ant test-canoo" which runs through all the JSPs using Canoo's WebTest (server already started):
  • Resin: 1st run (no compiled JSPs) - 53 seconds, 2nd run (compiled JSPs) - 24 seconds.
  • Tomcat: 1st run (no compiled JSPs) - 49 seconds, 2nd run (compiled JSPs) - 14 seconds.

I did have to hack a number of things to even run the tests (which verifies titles, success messages, etc.) on Resin. First of all, SiteMesh seems to puke with if you try to use <dispatcher>FORWARD</dispatcher> on the filter-mapping. I had to comment this out, resulting in a lots of HTML Tidy errors during the tests ( Error: <content> is not recognized!). I also had to turn off Resin's fast-jstl to bypass this bug. Finally, I had to revert the displaytag to using the non-EL version (which required changing titleKey -> title and name="${listName}" -> name="listName"). It seems that Resin enables EL even if you're using a 2.3 DTD. With Tomcat, and I believe the spec says this, EL is only enabled if you use a 2.4 XSD.

So there you have it folks, not only is Resin 3.0.9 slower than Tomcat 5.0.28 (JDK 1.4.2, Windows XP), but it's not standards compliant. Of course, the speed could be due to my using the open source version (with performance enhancements turned off) - but I'd think the other (albeit minor) stuff should be easy to fix. Everytime I try to use Resin, I end up finding bugs and going back to Tomcat. I guess this is another one of those days. I don't think I'll include a Resin installer as part of 1.6, but I might distribute one later if I can get these issues solved. I wonder if I should give Orion a run for its money?

P.S. Since I know people are going to ask: Tomcat 5.5.3 with JDK 5.0 took 9 seconds to startup. Running "test-canoo"? First run: 37 seconds, second: 14 seconds. Looks like the new compiler is quite a bit faster.

Resin now Open Source?

I noticed on the release notes for Resin 3.0.9 (released last Saturday) that they now have an open source (GPL) version.

Resin Open Source (GPL) - Contains all functional components of Resin, including EJB, but excludes performance and clustering capabilities.

Excludes performance capabilities? What does that mean - is it slow on purpose?

I was planning on looking at AppFuse on Resin again tonight and hopefully figure out a way to make it easy to setup/test/deploy on Resin instead of Tomcat. Since AppFuse currently works fine on Resin, this shouldn't be too hard. The hard part is going to be finding a non-obtrusive way to setup Resin.

With Tomcat, I can copy a couple JARs to $CATALINA_HOME/common/lib and an appfuse.xml file to $CATALINA_HOME/conf/Catalina/localhost and the app is setup and ready to go. Better yet, I can use Tomcat's Ant tasks to deploy a WAR with an embedded context.xml file and it'll get copied to the appropriate location.

Is there a similar system that Resin allows? I know I can do the copy-JAR thing. However, the last time I checked, you had to manually edit the resin.conf file to import a <web-app> definition.

Laszlo Goes Open Source

It's awesome to see that Laszlo has gone open source. The main reason I haven't dug into Macromedia's Flex is because it's $12K per CPU. I agree that this it's probably worth it if you're after a nice user experience - but most of my clients want open source, and only open source. It's tough to find folks that'll pay for JIRA even - if you can believe that.

With Lazlo going open source, it opens a whole new world for me. Now there's an opportunity to use this technology with clients. Of course, now I have learn the stuff so I can be productive enough to convince them to use it. I may even add a Lazlo front-end to AppFuse, but probably not until next year, after Tapestry and JSF. Hmmm, if JSF is really all that - can it render a Laszlo UI? That'd be wicked.

The Beauty of SiteMesh

I'm pumped that I recently switched from Tiles to SiteMesh in AppFuse. Not only was it easy to learn when I integrated it into Equinox, but it easy to replace Tiles with SiteMesh in AppFuse.

The best part of SiteMesh is once you have it setup and configured, you rarely have to muck with it again - it just works. In fact, it's so non-obtrusive that when I re-worked all AppFuse's tutorials last week, I was able to delete a whole tutorial. That's right folks, by removing Tiles and going with SiteMesh - the number of tutorials dropped from 5 to 4. Reduction in code and words needed to explain it is always a good thing.

Furthermore, SiteMesh continues to be evolving and getting better. Good stuff.

BTW, did you know you can use SiteMesh-style templates in your Roller blog? I'm using this feature on JRoller and it works great.