I have web app deployed on weblogic 9.2. There are several reports, each having a input jsp, a output jsp, a java support bean and a export page to export output generated to excel file.

The user feeds input through input jsp. The output jsp reads ip parameters & instantiates a supportbean, which in turn gets input & after processing gives output.

Now, there is a need for some reports to automatically get fired, let say every hour from 9 to 5, and output excel file be emailed.

How it can be implemented?

For mailing you can check the Java Mail API..
For writing the reports to an Excel proprietary format you will need Apache POI I guess.

Now for it to get automatically fired, I guess you need to create a small application (maybe in Core Java) which will run round the clock, and at specified time intervals (specified in its configuration file or maybe in the database) will fire a request on your JSP page using the required parameters. So for this you will need to know how to perform an HTTP Post / Get request on a remote URL via Core Java, so here is an example on that.