(1)pageScope：获取jsp中pageContext域属性，相当于pageContext.getAttribute("xxx")
(2)requestScope：获取request域属性，相当于request.getAttribute("xxx")
(3)sessionScope：获取session域属性，相当于session.getAttribute("xxx")
(4)applicationScope：获取application域属性，相当于application.getAttribute("xxx")      

        【jsp中】         【EL表达式中】       
         Page             pageScope
         Request          requestScope
         Session          sessionScope
         Application      applicationScope

pageScope / requestScope / sessionScope / applicationScope