Raible Designs

Java Development with Ant, The Application

If you've been fortunate enough to read Erik Hatcher's Java Development with Ant, you know that there's tons of good tips in it. I read it and I've been recommending it every since. Erik has been continuing development of the sample app for the book ever since it was released. I got many tips from Erik in developing AppFuse and I have to say, it really is a nice example. Maybe I'll get some more stuff now that it appears to have jumped from version 0.4 to 0.9! Here's a message Erik sent about the latest release.

All -

I'm proud (and worried about the support e-mails! :) to announce the 
near-final release of a project demonstrating Ant, XDoclet, Struts, 
JUnit, Cactus, and Lucene.  Its called JavaDevWithAnt as it was written 
for the book Steve and I co-authored and has been refined during 
several presentations I've been giving on Ant, XDoclet and Struts.

The documentation is in draft stage, and my primary goal is to collect 
feedback on polishing the documentation (and the application if there 
are any bugs that surface).  The site where I'm hosting the 
distribution and documentation is:

	http://www.ehatchersolutions.com/JavaDevWithAnt/

Please let me know if you try it out and have suggestions for 
improvement, or just to let me know you tried it and hate it or love 
it, etc.  Feedback more than welcome!  Direct feedback to me at 
[email protected]

	Erik

p.s. Since this e-mail is directed to the XDoclet, Lucene, and Cactus 
lists, here is a brief teaser for you:

XDoclet - its used extensively, even using a custom tag handler to 
generate starter JSP's from Struts form beans.

Lucene - my <index> Ant task is used to index text and HTML files, and 
Lucene's API is used at run-time to query the index.

Cactus - StrutsTestCase is used, although no direct Cactus tests.

Happy information-overload! There's a lot there, but if I could figure it out - I'm sure you can. Erik - finally on Jaguar eh? What took you so long ;-)

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!

ChainedExceptions and BeanUtils.copyProperties

I am wondering about a few things, so thought I'd try and get some help from the best source I know - the java.blogs community. First, an update on last night. I experienced some difficulty with Hibernate (persisting child objects) and Struts (nightly build doesn't quite work right with Tiles and Modules) and gave up at 2:00 a.m. Luckily, my head cleared up this morning after a deep 4 hours of sleep and I figured out Hibernate and it appears that a fix for the Tiles/Modules problem was checked into CVS by Cedric.

Now I'm wondering if it's possible to use declared exceptions in Struts to grab all your Exceptions from the bottom up. I can do this in an Action (or even a filter) using the following:

// caught exception e
ActionErrors errors = new ActionErrors();
errors.add(ActionErrors.GLOBAL_ERROR,
           new ActionError("errors.general"));

while (e != null) {
    errors.add(ActionErrors.GLOBAL_ERROR,
               new ActionError("errors.detail", e.getMessage()));
    e = (Exception) e.getCause();
}

request.setAttribute(Globals.ERROR_KEY, errors);

Can I do this with declared exceptions? Man that would be sweet if I could - I wouldn't have to have any exception handling in my Actions. Maybe that's the easy way out, but it also makes for rapid development - and you can always add them in when you really want them. Two other things I need to do.

• I have a java.util.Set on my User (Hibernate) object. This refers to a collection of Resume objects. When I generate my StrutsForms, I need to do something in my XDoclet template to turn a java.util.Set into a java.util.ArrayList. I don't know that I have to do this, but I've always used ArrayLists or Vectors on ActionForms for child objects.
• I am using BeanUtils.copyProperties in a Business Delegate to transfer properties from my User object to a UserForm object. When I do this, the child objects come through as Resume objects - where I really want them to come through as ResumeForms. Is this possible using BeanUtils, or do I have to do this manually?

I should probably do some research now to try and figure this stuff out on my own - but hopefully an answer will come through while I'm doing that ;-). I'll post to the proper mailing lists if I can't figure it out by COB. BTW, if you're using Hibernate, the FAQ is awesome. I wish more OSS (or closed-source software) had documentation this good.