How do I detect the environment in Salesforce?

Question

I am integrating our back end systems with Salesforce using the web services. I have production and stage environments running on different URLs. I need to be able to have the endpoint of the web service call be different depending on whether the code is running in the production or sandbox Salesforce instance.

How do I detect the environment.

Currently I am considering looking up a user to see if there user name ends in 'devsandbox' as I have been unable to identify a system object that I can query to get the environment.

Further clarification:

The location I need to determine this is within the Apex code that is invoked when I select a button in Salesforce. My custom controller needs to know if it running in the production or sandbox Salesforce environment.

Answer 1

For y'all finding this via search results, there is an important update. As Daniel Hoechst pointed out in another post, SF now directly provides sandbox vs. production information:

In Summer '14, (version 31.0), there is a new field available on the Organization object.

select Id, IsSandbox from Organization limit 1

From the release notes under New and Change Objects:

The Organization object has the following new read-only fields.

InstanceName
IsSandbox