How to set and destroy a session variable in struts2? - struts2

Question

I'm a beginner in Struts2. I am used in PHP, while logging to save authentification in a session variable, which I can destroy after logging out. I wonder how I can do the same process in Struts2 : to set a session variable while logging in and to destroy it while logging out. Thank you a lot.
Update ( An additional solution )
In addition to the useful answers and comments, we can use :
session.remove("session_var_name"); // instead of session.clear();
to remove one exact session variable instead of removing all the session variables. Thank you all.

Answer 1

You can do one of the following
public class MyAction extends ActionSupport implements ServletRequestAware
{
private HttpServletRequest httpServletRequest;
public void setServletRequest(HttpServletRequest request)
{
this.httpServletRequest = request;
}
public String login()
{
httpServletRequest.getSession(false).setAttribute("key", your_session_object);
return SUCCESS;
}
public String logout()
{
httpServletRequest.getSession(false).removeAttribute("key");
return SUCCESS;
}
}
public class MyAction extends ActionSupport implements SessionAware
{
private Map sessionMap;
public void setSession(Map map)
{
this.sessionMap = map;
}
public String login()
{
sessionMap.put(key, your_session_object);
return SUCCESS;
}
public String logout()
{
sessionMap.remove(key);
return SUCCESS;
}
}
The second alternative i.e. implementing SessionAware is preferred since it shields you from Servlet APIs.

Answer 2

You can use Scope Interceptor when you call logout, and with "end" type in your struts xml configuration, Interceptor set null to your session object:
<action name="scopea" class="com.mevipro.test.action.ScopeActionA">
<result name="success" type="dispatcher">/jsp/test.jsp</result>
<interceptor-ref name="basicStack"/>
<interceptor-ref name="scope">
<param name="key">funky</param>
<param name="session">person</param>
<param name="type">start</param>
</interceptor-ref>
</action>
<action name="scopeb" class="com.mevipro.test.action.ScopeActionB">
<result name="success" type="dispatcher">/jsp/test.jsp</result>
<interceptor-ref name="scope">
<param name="key">funky</param>
<param name="session">person</param>
<param name="type">end</param>
</interceptor-ref>
<interceptor-ref name="basicStack"/>
</action>
you must define "start" and "end" the start is when you initialise your object in session and the "end" for destroy your object
For more detail : https://struts.apache.org/docs/scope-interceptor.html