Once upon a time, all good software used some sort of a command language. Whether it was a word processor like Emacs, a typesetting program like TeX, or even something like a graphing program, everything had a command line at the bottom and some kind of command language that could …
Posted Mon 29 December 2008 by mcherm in Programming
Suppose you are setting up your database table, and you want to create a column to store an email address. How many characters should you allow in the field?
In Oracle (what I use most often), the correct type to use for an email is VARCHAR2(x) for some value …
Posted Wed 17 December 2008 by mcherm in Programming
As Willie Sutton didn't say, "I rob banks because that's where the money is."
I work for a bank, and so I worry more about security than most programmers. After all, if a hacker were were truly motivated and competent who would they pick to go after? Probably a bank …
Posted Thu 04 December 2008 by mcherm in Programming
In a previous post I wrote about how nearly all web applications built on Java servlets suffer from potential threading issues. Web browsers can make multiple simultaneous requests, which will result in multiple threads concurrently modifying the (not threadsafe) HTTPSession. Most people just ignore the problems (which strike rarely), some …
Posted Tue 07 October 2008 by mcherm in Programming
Web servers are inherently threaded applications: their primary purpose is to serve up a website or web application to a large number of users. Essentially all of the frameworks for creating web applications, such as Java's "servlet" specification and all of the structure built on top of it, provide built-in …
Posted Tue 23 September 2008 by mcherm in Programming