JSP/servlet read parameters from properties file?

Question

My JSP pages need to display different information depending on which environment they're in (dev, production, sandbox, etc). I want to have a properties file for each of these environments that contain all the parameters they might need. How can I reference the properties from this file in a JSP page?

My thoughts are:

• Have a servlet feed the properties in the form of a model object to all JSP pages so I can reference them like ${properties.propertyName}
• Somehow reference this property file in the web.xml, then maybe I call something like ${context.properties.propertyName}?
• Instead of a properties file, list parameters in web.xml and reference those in the JSP pages. Not sure how to do this, but I'd very much prefer a simpler properties file.

UPDATE - I should've mentioned I'm using Spring 3.0 and Spring webmvc. So if there's some best practices way to do this using Spring, that's ideal!

Answer 1

• You can load the properties using java.util.Properties (or commons-configuration) in a ServletContextListener's contextInitialized(..) method.

• register the listener with <listener> in web.xml

• You then store the Properties into the ServletContext (you can get it from the event) (ctx.setAttribute("properties", properties)

• then access the properties using ${applicationScope.properties.propName} (as BalusC noted, applicationScope is optional)

Update:

Initially I thought spring had some ready-to-use facility for that, but it turns out it's not exactly the case. You have two options:

• this article explains something similar to my suggestion above, but using spring's PropertyPlaceholderConfigurer

• this answer and this answer allow you to expose all your beans, including a PropertyPlaceholderConfigurer to the servlet context.