关于jstl表达式写法的实验

来源：互联网发布：js与jsp数据交互编辑：程序博客网时间：2024/06/06 06:54

步骤：
1、在filter中设置tools.business_school.mailType值为188，然后将其存放到session中。
2、在页面通过不同jstl表达式获取。

(1)采用
mailType in session scope = ${sessionScope.tools.business_school.mailType}
mailType in any scope = ${tools.business_school.mailType}
结果输出：
mailType in session scope =
mailType in all scope = 188
说明${sessionScope.tools.business_school.mailType}这个表达式有问题。

(2)修改为
obj in session scope = ${sessionScope}
mailType in session scope = ${sessionScope.tools.business_school.mailType}
mailType in any scope = ${tools.business_school.mailType}
结果输出：
obj in session scope = {tools.business_school.mailType=188, session_uid=gordonyellow@188.com, basePath=http://tools.188.com:80/tools, session_user_id=302746, path...}
mailType in session scope =
mailType in all scope = 188
说明tools.business_school.mailType已经存放到session中，但${sessionScope.tools.business_school.mailType}却获取不到该值，证明表达式不正确。

(3)修改为
mailType in session scope = ${sessionScope[tools.business_school.mailTypt]}
mailType in any scope = ${tools.business_school.mailType}
还是输出
mailType in session scope =
mailType in all scope = 188
说明${sessionScope[tools.business_school.mailTypt]}也不正确

(4)再修改为
mailType in session scope = ${sessionScope['tools.business_school.mailTypt']}
mailType in any scope = ${tools.business_school.mailType}
输出
mailType in session scope = 188
mailType in all scope = 188
说明${sessionScope['tools.business_school.mailTypt']}是正确的写法