With regards to the caching of data, I suspect it is your webbrowser that is caching it (try setting it to always check for a new version of the page, or even shutting it down between requests to verify this.)
You should be able to have Tomcat reload your application if it detects any changes. You will need to add a line to the server.xml file (in the tomcat/conf directory) to define your apllication context, and mark it as reloadable (using the reloadable="true" attribute)
Every time you make a change to your servlet (and recompile it) it SHOULD reload. I have known Tomcat be a bit unreliable w.r.t this, but give it a go
Sam
<a href="http://www.samjdalton.com" target="_blank" rel="nofollow">Sam Dalton</a>,<br />Co-author of [http://www.amazon.com/exec/obidos/tg/detail/-/1590592255/qid=1068633302//ref=sr_8_xs_ap_i0_xgl14/104-4904002-9274339?v=glance&s=books&n=507846]Professional JSP 2.0[/URL] (October 2003)<br />Co-author of <a href="http://www.amazon.com/exec/obidos/ASIN/1861007701/ref=ase_electricporkchop" target="_blank" rel="nofollow">Professional SCWCD Certification</a><br />Co-author of <a href="http://www.amazon.com/exec/obidos/ASIN/186100561X/ref=ase_electricporkchop" target="_blank" rel="nofollow">Professional Java Servlets 2.3</a>