Spring - HttpServletRequest object null when deleting JSESSIONID cookie? - java

I am testing a new functionality in my web app where i'm allowing the user to remain signed in even after the browing session expires. In order to achieve this, i have a "Keep me logged in" checkbox on my login page. Upon successful login, a cookie is created containing the userID and the login process continues normally. The first thing the first method in my main controller does is check for the presence of that cookie, read the userId in it, set the User object in the session correctly and bypass the login process, going directly to the home page. When the user signs out, the cookie is recreated with an expiration of 0 which means it's automatically deleted.
My Spring sessions last 30 minutes currently. I have successfully tested everything but i'm trying to replicate the Spring session expiring, which gets rid of the User object in memory and would normally force the user to login. In order to replicate it, i am deleting the JSESSIONID cookie from Chrome. When i do that, the HttpServletRequest object (which I am checking cookies on) is null.
Here is the first code that runs in my main controller :
#RequestMapping(value = {"/"}, method = RequestMethod.GET)
public String home(ModelMap model, HttpServletRequest request)
{
if (session.getAttribute("loggedInUser") != null)
{
return "home";
}
else
{
String userId = null;
for (Cookie cookie : request.getCookies())
{
if (cookie.getName().compareTo("MDHISStaySignedIn") == 0)
{
userId = cookie.getValue();
break;
}
}
if (userId != null)
{
session.setAttribute("loggedInUser", userService.findByUserId(userId));
return "redirect:/";
}
else
{
model.addAttribute("login", new Login());
model.addAttribute("register", new Register());
model.addAttribute("registering", false);
return "login";
}
}
}
Is it normal that my request object is null when deleting this cookie? Am i not correctly replicating the Spring session timing out by deleting it? This NullPointerException only happens when deleting this cookie and upon first running the web app, the controller does not thrown the exception when the cookie is created by the first run. Should i somehow be checking for this null value and redirecting the controller back to this method if it is?
Thanks!

The solution is to add the following method parameter :
#CookieValue(value = "MDHISStaySignedIn", defaultValue = "notFound") String cookie
This will assign the content of the cookie to the value if it's present and assign "notFound" if it is not. This way one can access cookies when the request object is null!

Related

How to store values in a servlet without re initializing them each time a servlet is called

I'm making a queue management system. I've hit on stump here. I'm letting the customer/user select their desired service whose token they want to get, but the thing is each time the servlet is called it re-initializes the service-option objects and the token number for that chosen services goes back to 1. How can I store the token count so that it doesn't goes back to 1 again.
public class XmlServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String Service_Option = request.getParameter("Service_Option");
out.println("You selected Service is: "+ Service_Option);
Customer_Console cc1 = new Customer_Console();
Customer_Console cc2 = new Customer_Console();
Customer_Console cc3 = new Customer_Console();
if(Service_Option.equals("Cash Withdrawal"))
{
cc1.setConsole(1,Service_Option);
Database_Manager.Insert(cc1);
}
else if(Service_Option.equals("Account Service"))
{
cc2.setConsole(2,Service_Option);
Database_Manager.Insert(cc2);
}
else
{
cc3.setConsole(3,Service_Option);
Database_Manager.Insert(cc3);
}
}
}
The Console class contains
private int serviceNum;
private String Service_Option;
private Token token;
and the setConsole method is
public void setConsole(int sNum,String sName)
{
serviceNum = sNum;
Service_Option = sName;
token.incrementToken();
}
UPDATE
I'm having problems with dealing the session for more then 1 customer consoles
HttpSession session = request.getSession(false);
if(session == null)
{
session = request.getSession(true);
Integer count = 0;
session.setAttribute("tokenCount",count);
}
if(Service_Option.equals("Cash Withdrawal"))
{
Integer count = (int)session.getAttribute("tokenCount");
count = new Integer(count.intValue() + 1);
cc1.setToken(count);
Database_Manager.Insert(cc1);
session.setAttribute("tokenCount",count);
}
Also how can I reset the session that every time I restart tomcat I get started with the token number 1.
If I'm supposed to use only one session for all three consoles then how can I do that?
I tried with placing the console objects
if(session == null)
{
session = request.getSession(true);
session.setAttribute("cc1", cc1);
}
if(Service_Option.equals("Cash Withdrawal"))
{
cc1.issueToken();
session.setAttribute("cc1", cc1);
cc1 = (Customer_Console)session.getAttribute("cc1");
Database_Manager.Insert(cc1);
}
But still it doesn't save the increments, again reinitializes the token, why is that?
Store Your service-option Object in session Scope So every time your servlet it called you can access the Object using
HttpSession session = request.getSession();
Console service-option=null;
service-option=(Console)session.getAttribute("console");
if(service-option==null){
service-option=new Console();
}
// After doing your work(setting some variables etc)of Console Class Object
// you can set that Object in Session Like this
session.setAttribute("console", service-option); // here "console" is key
In this way it is reinitialized only for the first time
As Java Docs Says
void setAttribute(String name,Object value)
Binds an object to this session, using the name specified. If an
object of the same name is already bound to the session, the object is
replaced.
Update
A HttpSession is created when calling request.getSession() and it get destroyed/invalidated when you call session.invalidate() or session timeout occurs .
Now coming to
Also how can I reset the session that every time I restart tomcat I
get started with the token number 1. If I'm supposed to use only one
session for all three consoles then how can I do that?
It will automatically get restarted but there will be no token number exist into it because it is fresh , if you need to access token number from your entire application then i suggest you to use Servlet Context
An object of ServletContext is created by the web container at time of
deploying the project.This object can be used to get configuration
information from web.xml file. There is only one ServletContext object
per web application.
If any information is shared to many servlet, it is better to provide
it from the web.xml file using the element.
Now your another confusion
I'm having problems with dealing the session for more then 1 customer
consoles
Please read Session Management in Java . As this topic is too broad so i have given you the link to read it yourself

Will tomcat return session in case of multiple cookies exist with name JSessionIDs

Consider a situation where tomcat server receives multiple cookies with name JSessionID out of which one JSessionID is valid, so tomcat will still return a session or not? If tomcat reads only first JSessionID and maps with stored sessions then it may not find valid sesison and may store null. But if tomcat reads all cookies with name JSessionID and checks for existence of session against each JSessionID then it will return valid session. Sometimes we have observed that browser sends two cookies with same name one which is recently authentication session and one some old cookie with stale value. Hence the query to know how tomcat behaves?
From the code in tomcat source, a jsessionid cookie will override a jsessionid in the query (provided the context allow to use cookie for session tracking).
If multiple jsessionid cookies are present the first one representing a valid session (for the considered context) will be taken.
see Tomcat 7.0.x CoyoteAdapter class :
/**
* Parse session id in URL.
*/
protected void parseSessionCookiesId(org.apache.coyote.Request req, Request request) {
// If session tracking via cookies has been disabled for the current
// context, don't go looking for a session ID in a cookie as a cookie
// from a parent context with a session ID may be present which would
// overwrite the valid session ID encoded in the URL
Context context = (Context) request.getMappingData().context;
if (context != null && !context.getServletContext()
.getEffectiveSessionTrackingModes().contains(
SessionTrackingMode.COOKIE)) {
return;
}
// Parse session id from cookies
Cookies serverCookies = req.getCookies();
int count = serverCookies.getCookieCount();
if (count <= 0) {
return;
}
String sessionCookieName = SessionConfig.getSessionCookieName(context);
for (int i = 0; i < count; i++) {
ServerCookie scookie = serverCookies.getCookie(i);
if (scookie.getName().equals(sessionCookieName)) {
// Override anything requested in the URL
if (!request.isRequestedSessionIdFromCookie()) {
// Accept only the first session id cookie
convertMB(scookie.getValue());
request.setRequestedSessionId
(scookie.getValue().toString());
request.setRequestedSessionCookie(true);
request.setRequestedSessionURL(false);
if (log.isDebugEnabled()) {
log.debug(" Requested cookie session id is " +
request.getRequestedSessionId());
}
} else {
if (!request.isRequestedSessionIdValid()) {
// Replace the session id until one is valid
convertMB(scookie.getValue());
request.setRequestedSessionId
(scookie.getValue().toString());
}
}
}
}
}

Tomcat response mix-up

Have been seeing a very unique situation. Need some input.
Background: We have tomcat servers on ec2 instances with ELB. Our application is a spring application which does not use sessions cause we didn't want the load balancer to track sessions. We use cookies to identify the user. We use Memcache to store some basic session information. For the most part everything works great.
Problem: In some remote cases 0.01% of the time (we analyzed) the response is getting mixed up between the users. And the users are usually coming from the same clientIP. We know this because our application is being used extensively by schools. The client cookie and the cookie we read in the servlet matches. We are positive our application is not looking up the wrong info in the DB. But the response (the view) that is getting rendered is for another user. We know both users are logged in at the same time.
Is this something Tomcat related? Or Network related?
Controller Code:
#RequestMapping("/kids")
public ModelAndView kids(HttpServletRequest request, HttpServletResponse response) {
StudentUserSession studentUserSession = BaseController.getStudentUserSession(request);
if(studentUserSession != null) {
ModelAndView mv = new ModelAndView("kids");
mv.addObject("studentUserSession", studentUserSession);
return mv;
} else {
return new ModelAndView("redirect:/signin");
}
}
JSP Code:
var acookie = readCookie("sp_utkn");
var studentId = ${studentUserSession.studentId};
$.getJSON("/getStudentProfile", function(data){
var sId = -1;
$.each(data, function (key, value) {
if(key == 'studentId'){
sId = value;
}
});
dojo.xhrGet({
url:"/logStudentEvent?cookie=" + acookie+"&stuId="+studentId+"&aId="+sId+"&ref="+otherInfo.join(','),
});
});
The JSON Get Call is getting the same object . aId matches with the cookie but studentId doesn't. The other data on the page are also for another user. But the cookies are consistent and accurate.

session servlets and href tag

what I'm trying to do is relative simple
In my webapp there are these two servlets:
(I will write some pseudocode)
servlet A code: :
HttpSession sess = req.getSession();
String str = (String) sess.getAttribute("log");
if(str == null)
{
// send html page with a form
// to enter password and name
// data will be proceessed by servlet B
}
else
{
// send html page with a form
// to enter only a name
//data will be proceessed by servlet B
}
servlet B code: :
HttpSession sess = req.getSession();
String logged = (String) sess.getAttribute("log");
if(logged == null)
{
//check if password correct
if(correct)
{
sess.setAttribute("log","ok");
// print name
// and tell the user
// that next time password
// will not be requested
}
else
{
// print error message
}
}
else
{
// print name
}
for some reason the second time the servlet A is called after that the user filled in password and name correctly
str is null so the if part gets printed.
EDIT:
I discovered that if the user after inserting the password and
being redirected to servletB writes the url of servletA by himself
all goes right , but it odesn't work when the user gets back to the previous
page using a link created by servletA:
A HREF=\"http://localhost:8080/Blog/ServletA\" back
again , any suggestions why this happens?
I believe its not entering in your if(correct) block i.e. correct condition is not getting satisfied. Correct the condition there and make sure, it sets the log attribute in the session. Once a attribute is set into the session, its there until session expires or your remove it.

Can't log out from Oracle SSO

I’m building a J2EE web application which uses Oracle SSO with an OID back-end as the means for authenticating users.
If a user wants to use the application, first he must provide a valid login/password at SSO's login page.
When the user is done using the application, he may click on the logout button; behind the scenes, the action associated with this button invalidates the user’s session and clears up the cookies using the following Java code:
private void clearCookies(HttpServletResponse res, HttpServletRequest req) {
res.setContentType("text/html");
for (Cookie cookie : req.getCookies()) {
cookie.setMaxAge(0);
cookie.setPath("/");
cookie.setDomain(req.getHeader("host"));
res.addCookie(cookie);
}
}
Also, I have an onclick JavaScript event associated with the logout button, which is supposed to delete the SSO cookies by calling the delOblixCookie() function (as found in some Oracle forum):
function delCookie(name, path, domain) {
var today = new Date();
// minus 2 days
var deleteDate = new Date(today.getTime() - 48 * 60 * 60 * 1000);
var cookie = name + "="
+ ((path == null) ? "" : "; path=" + path)
+ ((domain == null) ? "" : "; domain=" + domain)
+ "; expires=" + deleteDate;
document.cookie = cookie;
}
function delOblixCookie() {
// set focus to ok button
var isNetscape = (document.layers);
if (isNetscape == false || navigator.appVersion.charAt(0) >= 5) {
for (var i=0; i<document.links.length; i++) {
if (document.links.href == "javascript:top.close()") {
document.links.focus();
break;
}
}
}
delCookie('ObTEMC', '/');
delCookie('ObSSOCookie', '/');
// in case cookieDomain is configured delete same cookie to all subdomains
var subdomain;
var domain = new String(document.domain);
var index = domain.indexOf(".");
while (index > 0) {
subdomain = domain.substring(index, domain.length);
if (subdomain.indexOf(".", 1) > 0) {
delCookie('ObTEMC', '/', subdomain);
delCookie('ObSSOCookie', '/', subdomain);
}
domain = subdomain;
index = domain.indexOf(".", 1);
}
}
However, my users are not getting logged out from SSO after they hit the logout button: although a new session is created if they try to access the index page, the SSO login page is not presented to them and they can go straight to the main page without having to authenticate. Only if they manually delete the cookies from the browser, the login page shows up again - not what I need: the users must provide their login/password every time they log out from the application, so I believe there must be something wrong in the code that deletes the cookies.
I’d greatly appreciate any help with this problem, thanks in advance.
Oracle have two web SSO products - Oracle Access Manager and Oracle Single Sign On. The Javascript code you have posted is for Access Manager, so it won't help you. Besides, you shouldn't need to do anything in Javascript to log the user out.
Have a look at the logout section of the OSSO docs. It recommends using the following code:
// Clear application session, if any
String l_return_url := return url to your application
response.setHeader( "Osso-Return-Url", l_return_url);
response.sendError( 470, "Oracle SSO" );
You need a page, with a name of logout, that includes those JavaScript functions.
That's what the documentation says:
The WebGate logs a user out when it receives a URL containing
"logout." (including the "."), with the exceptions of logout.gif and
logout.jpg, for example, logout.html or logout.pl. When the WebGate
receives a URL with this string, the value of the ObSSOCookie is set
to "logout.
Cookies don't "delete" untill the browser is closed.

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