Raible Designs

WebWork Tutorial makes it look easy

I have to admit that this webwork tutorial makes WebWork look easy. In comparing this to Struts, it seems as if the Form and Action are the same thing. I wonder if I could use BeanUtils.copyProperties(wwAction, POJO) like I am with Hibernate/Struts currently.

The funny thing is that XDoclet has made it so easy (IMO) that I don't write ActionForm's anymore. All I really write is Actions, JSPs, DAOs and Services (a.k.a. Managers). So, with my current architecture I'm using, it actually looks like more work to use WebWork's Actions than Struts Actions. Especially since I have to write my validation in my Action. The XDoclet/Validator combo makes this super simple with Struts (and would with WW if they'd adopt it ;-). The only time I've been writing forms lately is when I have a form with indexed properties. Then I create a childForm that extends the generated form and has the appropriate accessors/mutators for the indexed properties.

The one thing the article does bring to light is how much cleaner Velocity is. JSP 2.0 will make JSP's a lot easier, but Velocity looks like it's already there. The one thing that worries me about using Velocity is that, according to their homepage, they haven't had a release in 8 months and their last release was a Release Candidate. What the?! Seems like someone might be dropping the ball on that project.

Struts Training: Week 4

I missed last week (Week 4, PosgreSQL), but I'm back this week - ready to report. I'm presenting next week on "remember-me" and XDoclet, so I'm working frantically trying to get AppFuse up-to-snuff to use as a lab template. Hopefully, I'll have that done by tomorrow night, as well as the lab and presentation.

Today's presentation is from James Turner on Indexed Properties and Validation. Awesome - I need this in my day job's project starting next week! Good timing, eh?!

So how do you use indexed properties in Forms? Two ways: Simple arrays of strings and arrays of beans (recommended). Here's a good tip - if you're using DynaActionForms, you can access a property in JSTL using {form.map.propertyName}. I did not know that - thanks James! Lots of good stuff in this one (too much to write down), I hope this preso is available online and a demo app goes with it. To validate simple array of strings, add indexedlistProperty to your <field> in validation.xml (you must also specify the property). If you're validating beans, use property="propertyName" and indexedListProperty="beanName".

However, do you really want to require all fields of your child beans? No, probably not. You (most likely), just want to require fields if some fields are populated. Struts provides us with the requiredif validator. No JavaScript validation exists for requiredif at this time. Hmmm, I wonder if XDoclet can generate indexed validation rules. Here's an example of how to do this with the current 1.1 RC1 Release.

<form name="myForm">
  <field property="lastName" indexedListProperty="person" 
    depends="">
    <arg0 key="label.lastName"/>
  </field>
  <field property="firstName" indexedListProperty="person" 
    depends="requiredif">
    <arg0 key="label.firstName"/>
    <var>
      <var-name>field[0]</var-name>
      <var-value>lastName</var-value>
    </var>
    <var>
      <var-name>fieldIndexed[0]</var-name>
      <var-value>true</var-value>
    </var>
    <var>
      <var-name>fieldTest[0]</var-name>
      <var-value>NOTNULL</var-value>
    </var>
  </field>
  ...
</form>

Note that the [0] is NOT an indicator of which indexed property to validate. RequiredIf is powerful but ugly, so James wrote something better. Unfortunately, it's too late for 1.1 and will be added for the 1.2 release. Sounds like most folks that use the Validator will be using a nightly build for awhile ;-). The new validator is called "validwhen," and looks as follows:

<field property="firstName"
  indexedListProperty="dependents"
  depends="validwhen">
  <arg0 key="dependentListForm.firstName.label"/>
  <var>
    <var-name>test</var-name>
    <var-value>((dependents[].lastName == null) or
                (dependents[].firstName != null))
    </var-value>
  </var>
</field>

Fricken sweet! James is sending me the code - cool! This will make my life soooooo much easier next week. Status of Struts 1.1 from James: they're working on getting the commons packages to a release state. Slides from today will be available at strutskickstart.com later this afternoon.

Which caching framework to use?

I discovered this afternoon (after I got everything working - thanks to Jason's comment) that the main process in the webapp I'm building (day job) takes 15 seconds to process. It could be have something to do with the fact that the HTML page itself is 1.5MB of data (view-source, save as). And it's a very lightweight page as we're using strict XHTML and mucho CSS. So now it's time to start looking into caching frameworks. For the web/JSP side, I'll probably use OSCache. It's seems to be more tried and true, and commons-cache is still in the sandbox. If any of your have experience, chime in so I don't pick the wrong one! Another method I'm going to try is using JCS with Hibernate. Since I'm using XDoclet already, all I have to do is add the following to the top of my persistable objects.

@hibernate.jcs-cache usage="read-write"

Struts Upgrade: 1.1 RC1 to Nightly Build (20030326)

I decided to upgrade from Struts 1.1 RC1 to a nightly build this morning, hoping to get the fix for the Validator bug that requires an Internet connection. I was also hoping to solve an issue I have where Eclipse thinks that ListUtils.sum(list1, list2) is deprecated (not so according to it's JavaDocs - Ant doesn't seem to think it's deprecated either... wierd). However, instead I was greeted with a couple of new deprecation errors that you might want to know about.

• ConvertUtils.setDefaultLong(long) has been deprecated. Again, not according to its javadocs.
• Action.MESSAGES_KEY deprecated in favor of Globals.MESSAGES_KEY

The good news is that the Validator bug is indeed fixed and I don't have to set my proxy host/port variables for Tomcat anymore.

DBUnit and CLEAN_INSERT

A few days ago I was trying to hook DBUnit into my test process so that my database would contain the same data before my JUnit tests are run. I had some issues getting it to work and later found that there was a bug in DBUnit's ant task. Basically, it was not allowing me to disable batch statements. Anyway, it's been fixed in CVS and now my JUnit tests (all run through a common test-module task) depend on a "db-load" task. Pretty cool and awful easy to configure. I'll be updating struts-resume/appfuse in the next few days to contain this slick trick. In the meantime, here's my db-load target. The file sample-data.xml is also built using Ant via DBUnit's "export" task.

<target name="db-load" description="Loads database from exported DBUnit file">
    <property name="operation" value="CLEAN_INSERT"/>
    <property name="file" value="metadata/sql/sample-data.xml"/>
    <dbunit driver="${hibernate.connection.driver_class}"
        supportBatchStatement="false"
        url="${hibernate.connection.url}"
        userid="${hibernate.connection.username}"
        password="${hibernate.connection.password}"
        schema="${hibernate.connection.schema}">
        <operation type="${operation}" src="${file}" format="xml"/>
    </dbunit>
</target>

[ANNOUNCE] Display Tag Library 0.8.5 Released!

I spent some time yesterday assembling the release notes, enhancing the build process, and updating the documentation for the display tag library. The result is a new release!

This release is primarily a bug-fixing release and also represents the first release from the project at SourceForge. If you would like to have a say in the future direction of this project, please join one of the mailing lists. [Release Notes] [Download]

Enjoy! I updated two projects with this new release today and it helped eliminate a lot of "workaround" code I had. The next thing I'd like to see - the ability to specify ResourceBundle keys for column titles.

Update: Ed Hill has updated this project's homepage with the latest examples and documentation.

DBUnit has released version 1.5

I'm using DBUnit on all many of my personal projects (appfuse, struts-resume, security-example, day job) right now and I really dig it. It makes things so much easier. Mainly I've been using it to populate a database with default data, and haven't made my JUnit tests depend on cleaning/inserting. Today I've decided to tackle this issue (clean, insert, run test) - so I trotted on over to dbunit.org and discovered a new version (1.5) was released at the beginning of this month. I'm hoping (haven't tried yet) that I can do an export and CLEAN_INSERT and my task will be finished.

BTW, I dislike the case of the name "Dbunit" and I prefer "DBUnit," so that's what I'll be typing it as - hope you don't mind.

What to do with my Chapters?

Julie suggested I just post them on this site. Then I got to thinking - what if all the authors made a PDF version of the book, and it was downloadable as the whole thing or as selected chapters. Let's say $5/chapter and you can pick and choose whichever ones you want. Sounds like a good idea, but the problem would be protecting the PDFs from being shipped around between friends. Or we could just give them away, in hopes that our knowledge would inspire others to hire us (as in a new job or a new book).

I don't know what to do, but I'd like to get my chapters out somehow. I'm afraid that if I just sit and wait, they'll never get out, and the technology will be old news shortly. The stuff I wrote about has staying power, but only until the next version of XDoclet and Struts.

I guess the good news is that I'll keep struts-resume up to date with the latest version, but the writing will be out of date by the end of the year.

Struts Training: Week 3

I just signed in for 3rd week here in Struts Training. I'm coming to you live from Chelan, WA. So on with what Ted has to say.

Ted's talking about persistence in Struts: Transaction Script vs. Domain Model.

Transaction Script - organizes business logic by procedure. Great choice for small applications with simple logic. For example, online auction, public search engine or an address book.

Domain Model - an object model of the domain. Has a rich variety of objects that incorporate both data and behavior. Ted mentions that the Domain Model is better for larger applications. For example, managing inventory for an online auction might require using the domain model.

What Ted is doing is using the Domain Model to separate Struts from his Actions - so that he passes around a DomainRequest, DomainResponse, and gets his form from a factory. To me, this looks like a good way to make your Struts layer a lot more complicated! ;-) At the same time, Ted is getting this information from Martin Fowler's Patterns (in Enterprise Architecture, ISBN 0321127420) book, so maybe I should move to the domain model. Naahh, I think I'll keep using the Transaction Script method - it's probably easier for folks to learn and would definitely be easier for rookies to maintain.

Onto Hibernate and how it works:

- POJO beans, encourages fine-grained
- Utilizes "persistence by descriptor"
- Provides DBA-friendly text queries
- Plays well with others
- Buffet-style implementation

IMO, if you're not using Hibernate, you should know why. If you're starting a new project, it's worth looking at. If you're using it, but not using XDoclet - you should be. XDoclet is the best way to avoid DD Hell (quoted from Erik Hatcher).

I didn't know that Hibernate supported a version - did you? Apparently you can specify that a property is a version and Hibernate will use it as you'd expect. Don't see that I have a need for that, but possibly. Would a struts-resume user ever want to keep old versions of their resume? I like to keep old versions of mine, but I have to admit, I never look at them again.

<version name="version" />

Ted just touched on how Hibernate can generate your database schema for you. This is a very powerful feature IMO - especially with struts-resume. It makes it nice for an example app. For instance, with struts-resume, you can run "ant setup-db" and it'll drop tables and re-create your db schema for you.

A student asks about the bottom-up approach - what if you already have a database. My advice? Try looking at Middlegen, its Hibernate Plugin in designed to create an XDoclet-enabled POJO from a database schema. There's also the Reverse Schema Generator that is included with Hibernate. I've used this one and it works great. I've never used Middlegen, but I should be considering that I tag the generated POJO up with XDoclet tags.

Interesting: Ted just mentioned that Gavin (Hibernate's Lead Developer) is working on a book for Manning. It is on Object Relational persistence and it uses Hibernate for its example apps. Erik Hatcher, at his preso on Wednesday, also mentioned that an XDoclet in Action book will be published soon by Manning. He even showed us the book's cover - so I'm assuming it will be published soon.

Hibernate's Fashionable Friends: XDoclet, Commons Logging, Commons DBCP, DynaBeans and Turbine Caching.

To learn more about this Hibernate, checkout:

· AgileData Website (Scott Ambler)
· Hibernate Homepage
· Struts Application Site (Hibernate example and Struts Resume both use Hibernate with Struts)

Vic still likes RowSets and SQL better. I'm guessing this is because he's a SQL expert. The nice thing about Hibernate is that it's query language (HQL) is very much like SQL and allows you to do complex joins. At least, to my knowledge, I've never done any fancy joins in the HQL, just in the mapping (*.hbm.xml) files.

Quote from Ted: This is the year of JUnit books. Watch for them this summer..

Now Ted is covering StrutsTestCase, a JUnit extension that hooks into Struts and Cactus. IMO, it's an awesome way to test Struts Actions - even easier than testing a servlet with Cactus.

Another book: JUnit in Action (Manning) by Vincent Massol and Ted. To be published this summer. Vincent is the lead developer on Cactus, so I expect this to be a great book. Right now, I wish I had written my first book for Manning rather than Wrox. :-(

The one bad part about today's session is that I had to use a calling card to dial in and at $0.35/minute, I'm up to about $25! I should probably sign off soon and save some cash...

Tapestry - are you using it? A student asks about it and Ted mentions that he views it as a presentation framework like Velocity. I've heard lots of good things about it, but have never used it. Ted admits that he uses Velocity and gave up on using JSPs a while ago.

Good stuff - thanks Ted, I'm signing off (the QA session is still in progress).

Good Humor from the struts-user mailing list

This made me laugh out loud, so I thought I'd share:

Hi, all -- I'm new to struts and I have a few questions. Since you are
the experts I'm sure you will be able to help me.

My boss wants to know how many people are using struts and how long it
will take to build our application using struts as opposed to our current
development process. We currently have a thousand monkeys sitting at a
thousand emacs editors. The application isn't completely designed yet,
and of course I can't release confidential information about our 
application but if you could give me an estimate of monkey-hours saved, 
that would be great.

I was able to download the struts-blank.war file but I am having trouble
setting it up. The first stumbling block was that it is misnamed. It
should be called 'struts-blank.zip' because it is in zip format. I had 
to open the file in hexedit to figure that one out. Hopefully the next 
version will have the right name???

The other problem I have is that I can't get my application to behave
properly. If the user types in their email address I want to be able to
check that it is a correct one and show the field red while they are
typing if it is not. I have a javascript that checks for the '@' sign but 
many people are typing in 'a@a'. Since I don't think so many people would
have the same email address we are losing valuable data. How can struts 
help me with this? Will it take many monkey-hours to implement?

Once I unzipped the file I could not find any README or INSTALL file. I
tried the usual 'make; make install' but that did not work. I went out
on the net to find some install instructions and I read one place that 
said I just had to stick the zip file inside my tom cat. I do have a cat, 
but she's female. Will that make a difference, or does struts only run on
male cats? Does it matter if they are neutered? Does each client need to 
have a male cat or just the server?