jsp调用JavaBean，class文件存放于..\MyWeb\WEB-INF\classes\packet下，但还出错

程序在JBuilder6下开发，并正常运行
但把jsp,class文件拷出来，在WebLogic6.1下，出错：
Parsing of JSP File '/exam.jsp' failed:
/exam.jsp(11): class 'test.examBean' could not be loaded
probably occurred due to an error in /exam.jsp line 11:
<jsp:useBean id="examBeanId" scope="session" class="test.examBean" />
请大家帮忙