非servlet从web.xml获取属性

Question

Are there any drawbacks to non-servlets java classes obtaining property values from web.xml?

There are not many examples online; I was wondering if this was an advisable path?

Answer 1

It's just an unnecessary dependency. It's easier to get property values from a properties file in the classpath and it doesn't require the code to run in a servlet container.

Reading the properties from web.xml will require your classes to access a ServletConfig , so your classes will all be dependent on servlets. You will be a lot better off with a properties file.

Answer 2

One pattern for non-servlet classes to lookup something already defined in web.xml is through the use of JNDI properties(For instance, some shared/cluster level attribute that defines whether this is a Dev/Test/Production environment).

The use cases are more granular and different from the ones defined in properties file. For vast majority of usecases, looking up from a property file is sufficient.