如何使用java代码来访问managed-bean 的属性?

managed-bean>
  <managed-bean-name>Person</managed-bean-name>
<managed-bean-class>demo.PersonBean</managed-bean-class>
  <managed-bean-scope>request</managed-bean-scope>
  <managed-property>
   <property-name>userName</property-name>
   <property-class>java.lang.String</property-class>
   <value/>
  </managed-property>
<managed-bean>

可以使用下面的代码来访问bean的属性:

 

FacesContext fc = FacesContext.getCurrentInstance();
String userName = (String)fc.getApplication().createValueBinding("#{Person.userName}").getValue(fc);