JSF异常:javax.el.ELException: Not a Valid Method Expression:

托管bean的代码:
# package pcenshao.pet_store.mbean;  
#   
# import java.util.Map;  
#   
# import javax.faces.context.FacesContext;  
#   
# import pcenshao.pet_store.Grobal;  
# import pcenshao.pet_store.SpringUtil;  
# import pcenshao.pet_store.entity.Adopter;  
# import pcenshao.pet_store.service.AdopterService;  
# import pcenshao.pet_store.vo.AdopterVO;  
#   
# public class AdopterLogin {  
#     private Adopter ad;  
#     private AdopterService as;  
#     private String msg;  
#       
#     public AdopterLogin(){  
#         this.ad = new Adopter();  
#         this.as = (AdopterService)SpringUtil  
#                     .getApplicationContext()  
#                     .getBean("adopterService");       
#     }  
#       
#       
#     public String login(){  
#         if(this.as.login(ad)){  
#             Map<String,Object> s=  
#                     FacesContext.getCurrentInstance()  
#                                 .getExternalContext()  
#                                 .getSessionMap();  
#               
#             s.put(Grobal.Type, Grobal.TypeAdopter);  
#             s.put(Grobal.User, ad);  
#               
#             return "success";  
#         }  
#         this.setMsg("用户名或密码错误");  
#         return "";  
#     }  
#   
#     public void setMsg(String msg) {  
#         this.msg = msg;  
#     }  
#   
#     public String getMsg() {  
#         return msg;  
#     }  
#   
#   
#     public void setAd(Adopter ad) {  
#         this.ad = ad;  
#     }  
#   
#   
#     public Adopter getAd() {  
#         return ad;  
#     }  
#       
# } 下面是faces-config.xml 
   1. <?xml version='1.0' encoding='UTF-8'?>  
   2.   
   3. <faces-config xmlns="http://java.sun.com/xml/ns/javaee"  
   4.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
   5.     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd"  
   6.     version="1.2">  
   7.     <!-- 
   8.         <lifecycle> <phase-listener> </phase-listener> </lifecycle> 
   9.     -->  
  10.     <managed-bean>  
  11.         <managed-bean-name>al</managed-bean-name>  
  12.         <managed-bean-class>pcenshao.pet_store.mbean.AdminLogin</managed-bean-class>  
  13.         <managed-bean-scope>request</managed-bean-scope>  
  14.     </managed-bean>  
  15.     <managed-bean>  
  16.         <managed-bean-name>ah</managed-bean-name>  
  17.         <managed-bean-class>pcenshao.pet_store.mbean.AdminHome</managed-bean-class>  
  18.         <managed-bean-scope>session</managed-bean-scope>  
  19.     </managed-bean>  
  20.     <managed-bean>  
  21.         <managed-bean-name>h</managed-bean-name>  
  22.         <managed-bean-class>pcenshao.pet_store.mbean.Home</managed-bean-class>  
  23.         <managed-bean-scope>request</managed-bean-scope>  
  24.     </managed-bean>  
  25.     <managed-bean>  
  26.         <managed-bean-name>r</managed-bean-name>  
  27.         <managed-bean-class>pcenshao.pet_store.mbean.Reg</managed-bean-class>  
  28.         <managed-bean-scope>request</managed-bean-scope>  
  29.     </managed-bean>  
  30.     <managed-bean>  
  31.         <managed-bean-name>login</managed-bean-name>  
  32.         <managed-bean-class>pcenshao.pet_store.mbean.AdopterLogin</managed-bean-class>  
  33.         <managed-bean-scope>request</managed-bean-scope>  
  34.     </managed-bean>  
  35.   
  36.     <navigation-rule>  
  37.         <from-view-id>/admin/al.jsp</from-view-id>  
  38.         <navigation-case>  
  39.             <from-outcome>adminHome</from-outcome>  
  40.             <to-view-id>/admin/ah.jsp</to-view-id>  
  41.         </navigation-case>  
  42.     </navigation-rule>  
  43.     <navigation-rule>  
  44.         <from-view-id>/login.jsp</from-view-id>  
  45.         <navigation-case>  
  46.             <from-outcome>success</from-outcome>  
  47.             <to-view-id>/h.jsp</to-view-id>  
  48.         </navigation-case>  
  49.     </navigation-rule>  
  50.   
  51. </faces-config>  下面是jsp页面
   1. <f:view>  
   2. <center>  
   3.     <h:form>  
   4.         <h:outputText value="#{login.msg}" style="color:red"></h:outputText>  
   5.         <h:panelGrid columns="2">  
   6.             <f:facet name="header">  
   7.                 <h:outputText value="领养者登录"></h:outputText>  
   8.             </f:facet>  
   9.             <h:outputText value="用户名:"  ></h:outputText>  
  10.             <h:inputText value="#{login.ad.name}" id="name" required="true"></h:inputText>  
  11.             <h:outputText value="密  码:"></h:outputText>  
  12.             <h:inputSecret value="#{login.ad.password}" id="password" required="true" ></h:inputSecret>  
  13.         </h:panelGrid>      
  14.         <h:panelGroup >  
  15.             <h:commandButton value="登录" action="#{login.login}"></h:commandButton>  
  16.         </h:panelGroup>         
  17.         <h:panelGroup>  
  18.             <h:message for="name"></h:message>  
  19.             <h:message for="password"></h:message>  
  20.         </h:panelGroup>  
  21.     </h:form>  
  22. </center>  
  23. </f:view>  
下面是出错信息:
javax.servlet.ServletException: Not a Valid Method Expression:
javax.faces.webapp.FacesServlet.service(FacesServlet.java:256)root causejavax.el.ELException: Not a Valid Method Expression:
org.apache.el.lang.ExpressionBuilder.createMethodExpression(ExpressionBuilder.java:209)
org.apache.el.ExpressionFactoryImpl.createMethodExpression(ExpressionFactoryImpl.java:57)
org.apache.jsp.h_jsp._jspx_meth_h_005fcommandButton_005f0(h_jsp.java:954)
org.apache.jsp.h_jsp._jspx_meth_h_005fcolumn_005f4(h_jsp.java:865)
org.apache.jsp.h_jsp._jspx_meth_c_005fif_005f1(h_jsp.java:824)
org.apache.jsp.h_jsp._jspx_meth_h_005fdataTable_005f0(h_jsp.java:291)
org.apache.jsp.h_jsp._jspx_meth_h_005fform_005f0(h_jsp.java:229)
org.apache.jsp.h_jsp._jspx_meth_f_005fview_005f0(h_jsp.java:157)
org.apache.jsp.h_jsp._jspService(h_jsp.java:114)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:428)
com.sun.faces.application.ViewHandlerImpl.executePageToBuildView(ViewHandlerImpl.java:444)
com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:116)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:106)
com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:144)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:245) 我实在是搞不明白了
如果我把AdopterLogin类里的login方法里的s.put(Grobal.User, ad);去掉
就没有错
为什么呀??真是郁闷 
请高手指教