下面这个异常是因为什么造成的啊？请指点一下！
exception
org.apache.jasper.JasperException: Unable to compile class for JSP
Generated servlet error:
D:\Tomcat5.2.8\work\Catalina\localhost\tesJasper\org\apache\jsp\mysecond_jsp.java:10: package net.sf.jasperreports.engine does not exist
import net.sf.jasperreports.engine.JasperRunManager;
