jsp gets session and session from action to clear and judge
- 2020-08-22 22:37:25
- OfStack
There are 1 methods for jsp to obtain the session value problem from action:
So I have an session in action ("sessionid","sessionValue")
1. Obtain with struts tag: < s:property value="#session.sessionid"/ >
2. < %=request.getSession.getAttribute("sessionid"); > session is also one of the built-in objects. You can use session directly, which is much more convenient than ES23en.getSession
We can also write it as < %=session.getAttribute("sessionid"); >
3. el expression: ${sessionScope. sessionid}
If the value is bean, it will look like ${sessionScope.bean.beanProperty}
General session time is 30 minutes if session exists
You can also empty session
Get session and set its value to null
So I have an session in action ("sessionid","sessionValue")
1. Obtain with struts tag: < s:property value="#session.sessionid"/ >
2. < %=request.getSession.getAttribute("sessionid"); > session is also one of the built-in objects. You can use session directly, which is much more convenient than ES23en.getSession
We can also write it as < %=session.getAttribute("sessionid"); >
3. el expression: ${sessionScope. sessionid}
If the value is bean, it will look like ${sessionScope.bean.beanProperty}
General session time is 30 minutes if session exists
<%
String id = "";
String username = "";
User user = (User)session.getValue("docUser");
// judge user Is null, if not, operate the following. Otherwise, null pointer exception will be reported.
if(user != null){
id = user.getId();
username = user.getUsername();
}
%>
You can also empty session
Get session and set its value to null
<%
Lduser lduser = (Lduser) ActionContext.getContext().getSession().get("lduser");
if (lduser == null) {
session.putValue("lduser",null);
out.println("session To shut down ");
%>