When running Tomcat for projects which have UTF-8-encoded text in URLS (e.g. get parameters for searches), don't forget to add the correct parameter (URIEncoding="UTF-8") in conf/server.xml:

    <Connector port="8080" protocol="HTTP/1.1" 

               connectionTimeout="20000" 

               redirectPort="8443" URIEncoding="UTF-8" />

Forgetting this just cost me half an hour, curses.