Im not so sure that precompilation of Java Beans are required. According to the following it is seems that when a browser requests a .jsp page that has the <jsp:useBean> embeded in it in an instance of the bean is created.

"The <jsp:useBean> action is one of the JSP standard actions (identified by the jsp prefix).The action creates an instance of the bean class specified by the class attribute and associates it with the name specified by the id attribute. The name must be unique in the page and be a valid Java variable name; it must start with a letter and can't contain special characters such as dots, plus signs, etc."