I am trying to figure out the same thing. Do you find out how to use jikes to be your jsp compiler? I uncommented the lines in tomcat/conf/web.xml to use jikes compiler but it doesn.t work.
Any help will be appreciated.
U have to make changes to the tomcat sources ...org.apache.tomcat.context.WebXmlReader.java....it sets the default properties......
change the method contextInit(Context ctx) to make it to read the web.xml from the conf dir.
u just have to uncomment the line where there is a call to the method readDefaultWebXml( ctx );. This should do it.