First of all, not all checked exceptions are bad; they might be used for event notification or to redirect processing based on certain conditions.
Using introduction, aspects can add new methods and variables to a class, declare that a class implements an interface, or convert checked to unchecked exceptions.
Methods in the DAO interface should throw checked exceptions only if the caller can reasonably be expected to handle the exception.
If you invoke a preexisting function that can throw a checked exception, you should write a wrapper function that catches and handles that exception; then, invoke the wrapper method from XSLT instead.