Thanks for the fast responses.
I checked the url provided below but have another question.
Check the last example.
With this example the name of the called JSP file has to be know in advance in order to set up the filter in the web.xml file. Is this correct?
Unfortunately the JSP's to be called by my program are comming from a database so there is no way to set up web.xml in advance.
Therefore this solution may not eb right for me, but the article was informative so thank you.