Raible Designs

Subversion - CVS Replacement?

I heard of Subversion this morning from Erik Hatcher's publisher. It looks to be a CVS replacement, but as I'm happy with CVS (and satisfied that I've learned it), I don't think I'll be using it any time soon. It comes from the folks at Tigris.org, who have also provided us with Scarab. I am using Scarab, or I've at least installed it at work and intend to use it on our project. Scarab is a bug tracking application that is cheaper than JIRA and supposedly better than Bugzilla. I wish I could use JIRA b/c I really like the product, but as with most things - clients just want you to do something with free tools, rather than shelling out some extra cash to get things like IDEA and JIRA.

BTW, I'm sure you've heard that IDEA is on sale now. Will I buy it? Nope, I'm in love with Eclipse. Would I buy it if I'd used it for more than 2 days? Probably, but everything is working as I like it in Eclipse, and I'm such an IDE-minimalist, it just makes no sense.

You might be wondering why I was speaking with Erik Hatcher's publisher this morning? Heck if I know?! He sent me an e-mail saying that Erik had recommended me as a source for the newest and coolest Java Tools. Thanks Erik - but I don't know that I'm much of a source. I told him I thought that Maven, XDoclet and Hibernate would probably get a lot of attention in the coming months. He was interested in seeing if they deserved books. I don't think XDoclet does, as it's got so many different modules, it would be difficult to cover them all. It would be VERY cool to see a book written that develops an application using these tools.

This is why Erik's book is popular - people can take stuff from it and learn. Sure, they learn initially by copy/paste, but it's still learning. Hibernate probably deserves a book as I can't seem to grok it - although I did delete approx. 100 lines of code today after I learned some good tricks. I don't know if Erik's publisher was serious, but he did ask me if I'd be interested in writing a book. I told him "thanks, but no thanks" - Julie has asked that I never write a book again. I can't blame her, it's too much stress and computer time in my opinion. Especially considering that I killed my weekly Virus Scan (Friday nights) for the 10th time since I'm working (again) on a Friday night. It hasn't run in over two months!

I'd definitely like to speak about this stuff, maybe at conferences or such. Of course, I'd have to learn a helluva lot more before I could make that happen.

Copying Properties: The Good, the Bad and the Ugly

I realize that having an ActionForm and a POJO with the same getters/setters is ridiculous, but please bear with me for this example. I have a Form and a POJO with Strings, Longs and Dates. The Longs and the Dates get converted into Strings when I get the data from the database using BeanUtils.copyProperties. This works great.

BeanUtils.copyProperties(userForm, user);

However, when going back, it's a different story - here's the ugly way:

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

Date dateChanged = format.parse(userForm.getDateChanged());
Date dateCreated = format.parse(userForm.getDateCreated());

user = new User(userForm.getUserId(), userForm.getPassword(), 
                Long.valueOf(userForm.getDesktopId()),
                Long.valueOf(userForm.getCubeId()), 
                userForm.getCreatedBy(), dateCreated,
		userForm.getChangedBy(), dateChanged);

While this works, it's ugly and a pain. I want something like the ActionForm-Value Object mapper. This mapper allows you to easily copy properties between VOs (or Hibernate Objects) and Forms, and vise-versa.

vo = FormToVOMapper.map(form, new ExampleVO());

So I could do something as simple as user = FormToVOMapper.map(userForm, new User()); I like this mapper and I used it on my last project, where it works great. However, I get the feeling that developers in the Struts Community are using something better - and I want to use it. So please, tell me what it is and lets figure out the best way to do this. Another method I've used in the past is to set the VO (or object) on the form itself, allowing for setting of Strings without copying - and setting dates on the form, to be manipulated by the setter. This framework worked great, and I was actually the happiest with it out of any of the above. Chime in and give me your opinions!

Erik Hatcher's Blog

I saw it a couple weeks ago, but now Erik appears to be updating it regularly. Just in case you didn't know - you can find it here. Erik is an Ant Guru and has written many cool Struts extensions (i.e. LookupDispatchAction, XDoclet integration). He's made my life a lot easier with his Ant wisdom and Struts goodies - thanks Erik.

Jakarta's POI

I went to the kick-off party for my project tonight - too bad no one I'll be working with showed up! Oh well, everyone else that was there was very cool. Margaritas and nachos is always fun. I finally met the recruiter I've been working on the phone - and she's even cooler than she sounded on the phone. Apparently, there was a requirements meeting for the project on Monday. Doh! That would've probably been a good meeting to attend.

I heard that the hardest requirement will be parsing/reading Excel files, on a Unix box. I think the ol' POI project can come to the rescue for us.

The POI project consists of APIs for manipulating various file formats based upon Microsoft's OLE 2 Compound Document format using pure Java.

OLE 2 Compound Document Format based files include most Microsoft Office files such as XLS and DOC.

You just gotta love open source!

Eclipse Plugins and Hibernate

I found a new site with a list of Eclipse plugins tonight. I was hoping that the Ant View plugin could solve my Ant problems in Eclipse, but I can't seem to figure out what it does. I gave it the ol' 30 seconds of investigation - maybe I should read the documentation. The problem I'm having now is (after swapping Ant 1.4 jars for 1.5.1) is:

Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.

Hmmm, works fine from Cygwin, and Eclipse (2.0.2) has tools.jar and rt.jar in the classpath. Must be time to download a nightly build.

There was a lot of talk today in the java.blogs community about Hibernate. I'm happy to see this as it feels like I just bought a new car and everyone is saying it's the best car on the road. I decided to use Hibernate based on Dave's implementation in Ag. It looked easy enough, so I figured - why not?! It turns out, at the same time, that the XDoclet folks were in the midst of creating a new hibernate module in CVS. In fact, I got the hibernate module from Joel Rosi-Schwartz (I'm assuming a hibernate developer) before it was even in the XDoclet source tree.

I got to be a guinea pig in making hibernate tags work with XDoclet. I have to say that with Dave's working example, I was able to markup a POJO with hibernate/xdoclet tags and generate my persistence layer in a matter of minutes. It just worked. Kinda like Tomcat IMHO. That's how software should be. Check out my security-example if you're interested in using Hibernate with XDoclet. The readme in the source will explain how to run initial generation and tests. Currently, it generates a Struts Validator Form and VO from an Entity bean (located at src/ejb/org/apache/template/User.java). Why? Because Struts Forms can only be generated from Entity Beans. This needs to change IMO. But at the same time, the EJB architecture is already in place, I just need to execute the ejb-related tasks, and I'm in business.

In other news, a couple of Struts related goodies:

• ONJava.com has an introduction to the Validator Framework by Chuck Cavanass, an Introduction to Eclipse and Creating Reports with FOP. I used FOP on a project last year around this time and it's super slick. It's basically using XSL to generate PDF and RTF from an XML file. I highly recommend using something like RTF2FO to generate an XSL Template from a Word document.
• Struts Kick Start is now shipping from Amazon. I'd buy all the Struts books just to say you have them. I've got three ;) Haven't read any. Damn, I wish I had the time! Reading Erik Hatcher's Java Development with Ant was one of the smartest things I did this year. Actually, the smartest thing I did was get my wife pregnant
• I downloaded TogetherSoft's Control Center to do some UML Modeling for the Struts Chapter, and found that they use Struts on their site. Nice...

XDoclet and EJBs

I saw the following on the xdoclet-user mailing list today:

Chapters from Manning's "EJB Cookbook", by Ben Sullins and Mark Whipple will be made available on TheServerSide for public review. A chapter on "Code generation" is now available for download. "Code generation" presents the most common uses of XDoclet, an open source tool, tightly integrated with Ant, that lets you generate source code or other files.

Also, I just received the following e-mail from a fellow Denverite, Mike Clark:

Subject: Nice Blog

Hi Matt!

I've been enjoying reading your blog for a while and meaning to introduce myself since we both live in Denver. I'm speaking at the DJUG in April, so perhaps we can meet each other there.

By the way, my weblog is at: http://www.clarkware.com/cgi/blosxom.

Nice - gotta like e-mails like that!! Apparently, Mike is the Author of BitterEJB and also has some chapters for review at TSS:

If you're into JMS and message-driven beans, my "Bitter Messages" chapter is up for review on TheServerSide. As always, any feedback you might have is greatly appreciated!

Best OSS License?

I've gotten approval from Wrox to use struts-xdoclet as my sample app for my chapters on Security and Struts. I've also received committer rights from Ted Husted on the Struts project at SourceForge. I haven't checked anything in yet, because I still don't have a good name. While I think struts-xdoclet is a good descriptive name, it doesn't have the pizzazz I'm looking for. So the naming discussion continues. I'm thinking of actually leaving "Struts" out of the name as it seems to make other names more difficult when combined. I like the idea of kindling, which we use to start fires at the cabin, but I don't know if that makes a good app name.

Back to the point of this post, what are your recommendations for a good open source license? I don't really care how people use struts-xdoclet, so do I even need to license it? What happens if I don't include a license?

Struts WML Tag Library

A Struts WML Tag Library has been posted to the struts-dev mailing list. It's a "pre-release", which means the project is probably not stable, but I'm guessing the technology and tags are.

Struts-wml taglib, 'raw prerelease' is available here:

http://sourceforge.net/projects/struts-wml/

Here's the release notes:

This is a fully functional 'prerelease' which includes source code, sample application, documentation, binary and libraries. It's still somewhat unpolished (therefore raw prerelease). If you're willing to hack arround with it a little bit, you're welcome to download it. Please don't forget to contribute your changes back to the project! [Full Post]

Now it's your responsibility to get a WML project that you can implement this on!

Form-Based Authentication

I posted the following message to the tomcat-user group yesterday:

On Tomcat 4/5, I am able to use the following configuration in my 
web.xml:

<login-config>
  <auth-method>FORM</auth-method>
  <form-login-config>
    <form-login-page>/login.jsp</form-login-page>
    <form-error-page>/login.jsp?error=true</form-error-page>
  </form-login-config>
</login-config>

However, I know that there are app servers out there that do not support
this - the form-error-page MUST be a different JSP.  So I'm wondering,
is there a value I can grab in my login.jsp that tells me the URL of the
protected resource the user is trying to get to?

I tried <%=request.getRequestURL()%>, but that gives me .../login.jsp -
and I am expecting welcome.do.

I know iPlanet used to set a cookie and I could use that as described
here.

Thanks,

Matt

Craig McClanahan responded with the following answer - which was just the information I was looking for:

There is no portable mechanism to acquire the request URL that was originally requested, nor any guarantee that this is even possible. All you know is that the container has detected that a protected URL was requested, and that there was no currently authenticated user.

So the lesson learned is that if you want to make your webapp portable across different app servers, use two separate pages for the login and login-error pages.

Struts-XDoclet 0.1

I did a bunch of work today to get struts-xdoclet off the ground. Basically, all that exists write now is the generation of struts-config.xml and web.xml from xml files in a merge directory. There are no .java files in this project yet.

I'm posting this to you in hopes of getting some validation of the directory structure and Ant-based build/deploy process. The deploy task originally worked as Erik Hatcher suggests in his book, but whenever I tried to redeploy, it would give me errors when trying to remove a .jar file - so I resorted back to a simple copy to $CATALINA_HOME/webapps. The build.xml file I put together is based on what I found in struts-blank.war (for 1.1), roller's build process, my own experience and good ideas from the Ant book.

I've also configured form-based authentication and I plan to add a bunch of optional modules (i.e. SSLExt for SSL Switching, password encryption) to the mix.

I'm still searching for a sample-app idea for the persistence layer (i.e. authors and books). I'd like to do something that folks can use, so I'd definitely like to include an admin section for administering user's and their properties. Maybe even offer features such as registration (might be a bit difficult using tomcat-users.xml, but not so bad with JDBCRealm or an LDAP server), and password recovery.

You can download the first cut of this - which should build and allow you to login - at http://www.raibledesigns.com/struts/.

Next steps include the security modules I mentioned above, and generating validation.xml and persistence classes from a POJO. I'm still undecided on using Castor or Hibernate for the persistence layer. Dave (Johnson) seems to think Hibernate has some great stuff, and he's used Castor for a while, so that's probably the direction I'm leaning towards. It would be great do be able to do both.