Why are taglibraries and handlers so complex ?

Question

Not trying to offend anyone here. I developed a lot of servlet and jsp code in 1996-98, and then had to switch to
C++ due to project demands at a new employer. Now I get to make my own technology choices and I must say I am SO PLEASED to be back to java.
But now, I have to get up to speed with a lot of new features and some existing features (circa 97) that I never got around to before. I just took a look at tag libraries and tag handlers, and frankly it all looks overly complicated.
For example, in the "midnight" demo application ButtonHandler.java 234 lines of code and almost a dozen methods are dedicated to the herculean task of writing a localized version of this:
All this so you can add a button in jsp using the tag.
<fmt:message key="cookieTray" bundle="${bundle}"
var="buttonLabel" scope="page"/>
<midnight:button/>
Seems like a LOT OF CODE for a button. Wouldn't it be much easier to use a JavaBean? The bean could emit the entire button HTML, or you could simply use the jsp expression language to resolve the localized string attribute for the button label, and write the button manually in raw HTML.
Also, this seems like a lot of "registration code" connecting all the dots for a language that supports reflection.
Shouldn't this all be easier??
Thanks -- not meaning to offend anyone, please enlighten me, what am I missing?
MarcusWelby,

Answer 1

Shouldn't this all be easier??Yes it should be, and is.
235 lines in the file, much of which is comment, and another bunch which just looks like it was copied/pasted from a template of sorts.
The real meat of the the code is only about 5 lines, and I don't really agree with their approach here of using a page attribute called "buttonLabel".
Where do they document what page attribute is to be used?
Wouldn't it be better to specify the label with as an attribute of the tag? Or in the body maybe?
I would NOT use this as an example of how to write a custom tag.
If you do want to look at tag libraries, tag handlers, custom tags et al, I would recommend looking at
1 - JSTL
2 - Struts tag libraries
Both of which are open source. You can get the code from the jakarta project.
Those are what I consider reasonably well designed and implemented tag libraries.
Also note, that as of JSP2.0 there are "tag files" which make little snippets like this even easier to write.
Tag files are to TagHandlers what JSPs are to servlets.
Hope this helps,
evnafets