You need to have an Ant task which would compile, build and deploy your web application to Tomcat. JCreator internally makes use of an Ant build file, which is a simple XML. You could edit it to add some custom tasks.
JCreator is very simple to use. Just create new document give it jsp extension and point to place where you want document to be saved. Than do your coding and compile. Everything done. Be carefull with beans which are usually placed in separated folder than rest of classes( folder classes holds your compiled java files and some people like to put there another folder called beans). What I mean is, if beans saved in other directory then servlets, JCreator will create new folder inside beans called beanes and put there your compiled bean classes. Once you try run your servlet you get error telling you your bean classes can't be find