Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

ColdFusion, Random Numbers, and Time

DZone's Guide to

ColdFusion, Random Numbers, and Time

· Java Zone ·
Free Resource

The CMS developers love. Open Source, API-first and Enterprise-grade. Try BloomReach CMS for free.

A while ago I logged a bug I had discovered with ColdFusion REST services. I had created a simple REST service that returned a random number between one and one hundred. Nothing too complex, right? But then I noticed something odd. If I called the REST service with a cfhttp call twice, I got the same number back. I had discovered - I thought - a serious caching issue with REST services. Turns out I was wrong.

If you read the comments for the bug, you will see one in particular that stands out:

I assume this is one of the engineers, although I don't know. It makes sense - kinda - but I certainly didn't know this and I'm willing to bet most folks aren't aware of this either. As a long time computer programmer, I have a vague idea of the intricacies of random number generation. Apparently it involves quantum states, time travel, and zombie kittens.

The person helping out on the comment thread suggested using IBMSecureRandom as an algorithm for the randRange, but according to the docs this is only supported on WebSphere. I used SHA1PRNG and it worked immediately.

 

BloomReach CMS: the API-first CMS of the future. Open-source & enterprise-grade. - As a Java developer, you will feel at home using Maven builds and your favorite IDE (e.g. Eclipse or IntelliJ) and continuous integration server (e.g. Jenkins). Manage your Java objects using Spring Framework, write your templates in JSP or Freemarker. Try for free.

Topics:

Published at DZone with permission of

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}