automatically change configuration based on current environment

What if the application were aware of its different running environments so it could change its configuration automatically based on the current one?

If we wanted to do that, we had to solve 2 issues:

{% img http://2.bp.blogspot.com/-eiWPoCGfqzQ/Tz7KWbP8pLI/AAAAAAAAAEM/XzBpA6-RV3Y/s1600/steps.png %}

Fortunately for the second issue we have Spring 3.1 which introduced the concept of profiles to bean definitions. This is similar to what maven does to files but applied to beans.

Now, we can define different set of beans according to the current spring profile. If we structure our configuration in different sets of beans for each desired configuration we can change it easily.

The problem remains in how to detect the current environment to tell which spring profile to use.
(keep reading to know how...)