Error code and class mapping

[danielqiu]

In the rest-servlet.xml, you map each status code to a class:

<entry key="com.stormpath.blog.spring.mvc.rest.exhandler.UnknownResourceException" 
value="404, _exmsg"/>

In my app, I want to have a specific and unique error code for each error, for example,
1000, Error while inserting user with duplicated key
1001, Error while deleting user,
...
I might have hundreds or more for all the possible errors as the app grows. Or let's say we need to implement all the codes from http://www.twilio.com/docs/errors/reference and some other customized codes.

Do I need to create a class, like UnknownResourceException, for each of this? That would be tons of classes/files. Otherwise how can I create a couple of classes but serve all these errors in some way? If so how could I do that? Thanks!