first, please choose a meaningful title for your topic, as it's pretty obvious that it's about servlets if it's posted in the Servlets forum ;-)
Your question is more about Java in general. When overriding your method you may throw lesser, narrower, or no exceptions compared to the super class method. Having said that it is not possible to throw a broader exception in a servlet.
What you can do however is chain an exception meaning wrapping it in a servlet exception. That's common practice and looks like this.
JDBCSupport - An easy to use, light-weight JDBC framework -