Detect Session Timeout in Ajax Request in Spring MVC

Question

I can't see seem to find a good example/answer on how to send back some data from an ajax request when a session has timed out. It sends back the login page HTML and I want to either send json or a status code I can intercept.

Answer 1

The simplest way for doing this is using a filter on URLs of your AJAX requests.

In the example below I'm just sending HTTP 500 response code with a response body indicating the session timeout, but you can easily set the response code and body to what is more suitable for your case..

package com.myapp.security.authentication;

import org.springframework.web.filter.GenericFilterBean;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ExpiredSessionFilter extends GenericFilterBean {

    static final String FILTER_APPLIED = "__spring_security_expired_session_filter_applied";

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        if (request.getAttribute(FILTER_APPLIED) != null) {
            chain.doFilter(request, response);
            return;
        }

        request.setAttribute(FILTER_APPLIED, Boolean.TRUE);
        if (request.getRequestedSessionId() != null && !request.isRequestedSessionIdValid()) {               
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "SESSION_TIMED_OUT");
            return;
        }

        chain.doFilter(request, response);
    }
}