org.apache.catalina.util.DefaultAnnotationProcessor cannot be cast to org.ap

Servlet.service() for servlet jsp threw exception

java.lang.ClassCastException: org.apache.catalina.util.DefaultAnnotationProcessor cannot be cast to org.apache.AnnotationProcessor

at org.apache.jsp.login_jsp._jspInit(login_jsp.java:36)

at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)

at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:164)

at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:340)

at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)

at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

具体不知道是什么原因，在网上查说是tomcat lib中的jar包和java项目lib中的jar冲突。删除重复的jar包 或者修改tomcat里的context.xml文件，在context元素中添加 <Loader delegate="true" />  。第二种方法测试有效