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What I sort of look like

Just in case you ever want to scratch your eyes out: here's sort of what I look like when I look in the mirror.

My advice on how to vote

I don't normally tell people how to vote in the US - just to vote - but by gum, I'm as mad as I can be. I'm not going to tell you for whom to vote, nor can I tell you who I'll vote for, but I'll tell you this: my vote is for sale to any politician who'll meet these requirements.

Spring changes its license structure

The reason SpringSource's license change bothers me so much is not the specific change. It bothers me because Spring has done a good job embedding itself in successful projects, and now they've shown that they're willing to change the license, and I have no guarantee or confidence they won't change it to something more onerous in the future.

I have seeeeeeen the light, brothers and sisters!

I spent a lot of time on a specific architectural piece on an application I'm writing, only to run up against some thorny concurrency issues. I've always said that you should measure before optimizing; I didn't follow my own advice. Here's what I found when I decided to use completely unoptimized code... man, was I dumb.

Filtering characters from a Reader

It's an occasionally legitimate question: "How do I filter content from a Reader?" There're related questions for Streams, too. Here's an example of a simple Reader class that shows how to remove specific characters from a Reader.

How can I create a maintenance window for my web app?

Every so often, web applications need maintenance. Yes, even web applications. It's okay - no need to reach for your security blanket. The problem that's come up is: What's a good way to redirect requests during a maintenance window to an error page? As usual, there are multiple answers.

How can I automatically expire data from a database?

Another fairly common question: how can I expire data from a database? This is a case of applying lipstick to a pig: there are ways, to be sure, but the real problem is that you're using a database - a permanent datastore - to handle data that's short-lived.

My data structures have changed - how can I migrate my data model?

Sometimes, people design data structures, persisted entities, only to find that - gasp! - their data structures are more fluid than they expected. When all of your data is transient - meaning that it can be destroyed safely - that's no big deal, because you just drop the tables in question (or the whole database) and start over. (Sound familiar, Rails fans?) Sometimes, that's not enough - so what do you do?

How do I send mail with Java?

You send mail in Java with one of two APIs, basically: JavaMail and Commons-Email. People who use JavaMail fit in one of three categories: they don't know about Commons-Email, they are doing bulk mail and know what they're doing, or they're gluttons for punishment. Here's a class that shows how to send mail with both JavaMail and Commons-Email, for the case of sending to a single address.

How do I parse or format dates? Dates are hard!

Well, Barbie, dates are really pretty easy. Here's a class with a number of formatting and parsing examples.