错误：org.apache.jasper.JasperException: Exception creating bean of class app.LogonForm: {1}

错误消息：

HTTP Status 500 -

---

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Exception creating bean of class app.LogonForm: {1}
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
         ...

root cause

javax.servlet.ServletException: Exception creating bean of class app.LogonForm: {1}
	at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:533)
	at org.apache.jsp.Logon_jsp._jspService(Logon_jsp.java:85)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
         ...

控制台消息：
2005-9-19 9:35:30 org.apache.struts.util.RequestUtils createActionForm
严重: Error creating form bean of class app.LogonForm
java.lang.NullPointerException
        at org.apache.struts.config.FormBeanConfig.createActionForm(FormBeanConf
ig.java:212)
        at org.apache.struts.util.RequestUtils.createActionForm(RequestUtils.jav
a:292)
        at org.apache.struts.util.RequestUtils.createActionForm(RequestUtils.jav
a:191)

问题原因：没的将编译的类放到 WEB-INF/classes/app/下面。