JSP/JSTL: Versions and Standards

It baffles me. So many developers who use  infrastructure standards like servlets and JSP, but don't have any idea what versions of these they're coding to. They are blissfully unaware of whether they're targetting HTML4.01, XHTML-1 or HTML-5, CSS 2.1 or CSS 3, Servlet 3, 2.5 or 2.4...

Maybe I'm just funny that way - I think that managing dependencies in a tight, controlled way really matters! Otherwise things quickly spiral out of control, and you end up with that classic Design Pattern, "Big Ball of Mud".

On the other hand, I freely confess that I keep forgetting which pieces belong together. It's such a confusopoly.

So, mainly as a Note To Self, here's a quick lookup:

JSP/Servlet/JDK Versions

Servlets	JSP	JSTL	Java EE	Tomcat	Min. JDK
3.0	2.2	1.2	5	7.x	1.6
2.5	2.1	1.2	5	6.x	1.5
2.4	2.0	1.1	1.4	5.5.x	1.4

The list goes on, but if you still have systems in production running those archaic versions, you're probably in deeper trouble that mere version-confusion anyway!

Work Wanted

This is a small call for help. I am looking for work, and need your help.

Contract or permanent. Preferably (but not exclusively or even at all) telecommute. I can code, design, architect software, consult in any of these (and dev process/team issues) and teach a variety of Java, OO Design and web development topics, and would be happy to do any/all of these. I additionally have some experience doing system administration work. I work in Linux/Unix environments and know next-to-nothing about Windows.

I've done web stuff, and loads of backend "heavy lifting" coding where reliability, scalability, etc. are important. I am not good at quick'n'dirty. Skeptical of the value of buzzwords and big-arse frameworks.

Check out my "business" website for more details about me and what I've done in the past.

R (as they say) "highly neg".

If you have anything suitable, or know of anything that fits, please drop me a line.

I will be in Cape Town and environs next week, so an ideal time to get together and chat about possibilities and opportunities.

Android Nails Sandboxing

So I'm learning to programme the Android platform. Despite constantly typing it as "Androind" finding programming fun again after many years of regarding it as somewhere between tiresome drudgery and only mildly interesting in sporadic parts.

It's early days, yet, but I do think that Android's architects had one flash of brilliant insight: Using Unix user and group permissions to sandbox applications. Brilliant! We've had this mechanism since forever, and let's be honest, it's never been all that useful except in the very early years of Unix when we actually did have to put multiple users on a single computer. And even then, most users didn't understand it. Questions about umask and file permissions are among the commonest of Unix confusions I've run across for the past 25-odd years.

Warping the idea to mean that every application is a unique user is a flash of inspiration.

QOTD

'the idea of immediate compilation and "unit tests" appeals to me only rarely, when I’m feeling my way in a totally unknown environment and need feedback about what works and what doesn’t. Otherwise, lots of time is wasted on activities that I simply never need to perform or even think about. Nothing needs to be "mocked up."'

Donald Knuth 25 April 2008

(Okay, so I'm late to the party. As always.)

Design using Other Peoples' APIs

Where you are dependant upon somebody else's API, decouple from that API at the earliest possible opportunity so that the remainder of your system works in terms of your own abstractions rather than that somebody else's. This shields you from the random, spurious, and often unwarned changes they may make. It also enables you to place guards against the various stupidities they may likely perpetrate in the name of fashion or unthinkingness, and ensures that you are - as much as possible - forced to deal only with your own stupidities and unthinkingess.

This injunction includes decoupling from your own APIs where those are non-core to the subsystem under design.

Housekeeping Note - Server Change

Explaining why I've been so quiet lately: Migrating data and upgrading the software that runs the blogs and farm site (plus a bunch of other stuff) to a new server.  Yay upgrade!  Boo problems!  Just in time, too, it would seem, since the old server started mysteriously and frequently rebooting for no good reason, so I'm pretty sure that its been down more than its been up for about ten days now. :-(

Sorry if its all been very dodgy.

If anybody notices anything noticably untoward, please let me know -- I think I've moved everything over successfully, but not yet 100% sure, but, with the old server dying, I just want everything off it as soon as possible, so haven't had time to test all my new configuration properly.

Web Site Passwords

"Signing up" for yet another something-social-facebook-wannabe website, I was struck by a random Thought Particle.


Why do all these websites ask me to enter a password twice?

No, seriously! I know the stock answers. Hell, I've written such web-signup forms myself, more times than I care to think about.

Am I that likely to misspell a password? And who would care, when all I have to do is click a link that says something like, "I forgot my password!" to get a new password sent to me. Or a reminder. Or my original password. Or some other way of recovering from my "spelling error".

So, tell me again, why are we typing these things twice inthe first place?