Spring Framework 面试题与答案

Question: How do you control concurrent Active session using Spring Security?

Answer: You can easily control How many active session a user can have with a Java application by using Spring Security.

In fact is all declarative and no code is require to enable concurrent session disable functionality. You will need to include following xml snippet in your Spring Security Configuration file mostly named as applicaContext-security.xml. Here is sample spring security Example of limiting user session in Java web application:

<session-management invalid-session-url="/logout.html">
<concurrency-control max-sessions="1" error-if-maximum-exceeded="true" />
</session-management>

As you see you can specify how many concurrent session per user is allowed, most secure system like online banking portals allow just one authenticate session per user. You can even specify a URL where user will be taken if they submit an invalid session identifier can be used to detect session timeout. Session-management element is used to capture session related stuff. Max-session specify how many concurrent authenticated session is allowed and if error-if-maximum-exceeded set to true it will flag error if user tries to login into another session.