In an effort to help you get the most from our forums, we've compiled a list of tips for asking questions here. You can find the list in our FAQ section here. In particular, please see UseAMeaningfulSubjectLine .
That you posted in a 'Servlets' forum is enough for us to know that your question is about servlets. The subject line "servlet" gives us no hint as to the nature of your question.
Again, welcome to JavaRanch and good luck with your question. -Ben
From the API: "Returns the value of the attribute that has been added removed or replaced. If the attribute was added, this is the value of the attribute. If the attribute was removed, this is the value of the removed attribute. If the attribute was replaced, this is the old value of the attribute."
My feeling is that since getValue() returns the most recent attribute value, when an attribute is added or removed, I suspect that the API developers decided that if an event notification was going to be generated when the value is replaced it might be wise to be able to get the value of the attribute before it was replaced.
Note that if you need to get the new value of the request attribute, ServletRequestAttributeEvent inherits a getServletRequest() method which can then be used to get at the attribute's current (NEW) value.