package usersessions

import javax.servlet.http.HttpSessionEvent
import javax.servlet.http.HttpSessionListener

//import org.apache.shiro.subject.PrincipalCollection
//import org.apache.shiro.subject.SimplePrincipalCollection;
//import org.apache.shiro.subject.support.DefaultSubjectContext

class MyHttpSessionListener implements HttpSessionListener {
    private static List activeUsers = Collections.synchronizedList(new ArrayList());
@Override
public void sessionCreated(HttpSessionEvent event) { }

@Override
public void sessionDestroyed(HttpSessionEvent event) {
    String userName = getCurrentUserName(event)
    if (userName == null) {
        return
    }
    MyHttpSessionListener.userLoggedOut(userName)
}

public static void userLoggedIn(String userName) {
    if (!activeUsers.contains(userName)) {
        activeUsers.add(userName)
    }
}

public static void userLoggedOut(String userName) {
    activeUsers.remove(userName)
}

public static List getCurrentUserNames() {
    return Collections.unmodifiableList(activeUsers);
}
/*
private String getCurrentUserName(HttpSessionEvent event) {
    PrincipalCollection currentUser = (PrincipalCollection) event.getSession().getAttribute(DefaultSubjectContext.PRINCIPALS_SESSION_KEY);
    if (currentUser == null) {
        return null
    }
    return (String) currentUser.getPrimaryPrincipal();
}
*/

}

myHttpSessionListener(MyHttpSessionListener)
/*      shiroAuthenticator(ModularRealmAuthenticator) {
        authenticationStrategy = ref("shiroAuthenticationStrategy")
        authenticationListeners = [ ref("authListener") ]
    }
*/

package usersessions

class NewController extends MyHttpSessionListener {
    def index() {
        render "Users "+ getCurrentUserNames()
    }
 }