Visual Web JSF Navigation... Help!

I have an application whereby content should only be visible via logging in, on login a session object with the users details is created. I want to be able to check (if statement) whether this session object is null and if so, to throw the user back to the login page. My attempt at this was to have a hidden button whose action method returns "fail". I have also set up faces-config.xml to navigate to login when the outcome is "fail". So when the JSP runs, I perform an if statement and if the session variable is empty am trying to simulate a user clicking the button by calling its action method navigateToLoginPurrlease_action() . However I get no joy, is it possible to do it this way? how can one simulate a button being clicked without a user actually clicking it (i.e a hidden button purely for navigation purposes)?

Do not tight couple authentication with JSF. Just use a Servlet Filter.

Ok but as am new to this is it ok to elaborate just a little bit more, maybe even going as far as "How" i user the Servlet Filter?

Would greatly appreciate any help.

PS I would still love to know even just for the sake of knowing how I could have used session objects to fulfill the use case, navigating a user to the login page if the session object is null.

Implement javax.servlet.Filter and apply logic something like:
Simple as that.

Hello again,
bauke I have followed your advice, read about servlet filters and implemented the following filter:

package openhrs;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//import com.sun.rave.web.ui.appbase.AbstractPageBean;

/**
 *
 * @author Tumaini Kilimba
 */
public class SessionCheckFilter implements Filter {

private static int firstRequest = 0;

public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hreq = (HttpServletRequest) request;
        HttpServletResponse hres = (HttpServletResponse) response;
        HttpSession session = hreq.getSession();

String requestedPage = hreq.getPathTranslated();

//If the attribute loggedInUser in SessionBean1 is null (i.e user has
        //not logged in) redirect to the login page as long as its not the login page
        //being requested
        if (!requestedPage.endsWith("Login.jsp")) {
            
            if (((SessionBean1) session.getAttribute("SessionBean1"))
                    .getLoggedInUser() == null) {
                hres.sendRedirect("faces/Login.jsp");
                return;
            }
        }
        chain.doFilter(request, response);
    }

public void init(FilterConfig filterConfig) throws ServletException {
    }

public void destroy() {
    }    
}

However I get a java.lang.NullPointerException error as follows:

java.lang.NullPointerException
        at openhrs.SessionCheckFilter.doFilter(SessionCheckFilter.java:36)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:198)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:288)
        at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:271)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:202)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
        at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:206)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:150)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:632)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:577)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:571)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1080)
        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:272)
        at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:637)
        at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:568)
        at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:813)
        at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
        at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
        at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
        at com.sun.enterprise.web.portunif.PortUnificationPipeline$PUTask.doTask(PortUnificationPipeline.java:380)
        at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
        at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
deployed with moduleid = OpenHRS
Initializing Sun's JavaServer Faces implementation (1.2_04-b20-p03) for context '/OpenHRS'
deployed with moduleid = OpenHRS
Initializing Sun's JavaServer Faces implementation (1.2_04-b20-p03) for context '/OpenHRS'
deployed with moduleid = OpenHRS
Initializing Sun's JavaServer Faces implementation (1.2_04-b20-p03) for context '/OpenHRS'

Is there something wrong with my code? Please help.

Thanking you in advance

session.getAttribute("SessionBean1"))
.getLoggedInUser() == null)

Assumes the existence of attribute SessionBean1, which may or may not be null. However, if SessionBean1 has not been defined, the getAttribute() itself will return null. Hence the NullPointerException.

Thanks Tim, but where does SessionBean1.java need to be defined? It is a page bean in the same package as the calling class... Sorry for inconvenience but could you please elaborate a bit further?

Thanks again

Finally managed to do this. The following is how:

package openhrs;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.openhrs.vo.UserVO;
//import com.sun.rave.web.ui.appbase.AbstractPageBean;

/**
 *
 * @author Tumaini Kilimba
 */
public class SessionCheckFilter implements Filter {

private static int firstRequest = 0;

public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hreq = (HttpServletRequest) request;
        HttpServletResponse hres = (HttpServletResponse) response;
        HttpSession session = hreq.getSession();

String requestedPage = hreq.getPathTranslated();
        System.out.println("############## AM IN DO FILTER ##############");
        //If the attribute loggedInUser in SessionBean1 is null (i.e user has
        //not logged in) redirect to the login page as long as its not the login page
        //being requested
        if (!requestedPage.endsWith("Login.jsp")) {
            System.out.println("############## PAGE IS NOT LOGIN.JSP! ##############");
            try {
                if (((SessionBean1) session.getAttribute("SessionBean1")) != null) {
                    UserVO user = ((SessionBean1) session.getAttribute("SessionBean1")).getLoggedInUser();
                    System.out.println("############## SESSIONBEAN IS NOT NULL! ############## " +
                            (SessionBean1) session.getAttribute("SessionBean1"));

if ((user == null)) {
                        System.out.println("############## LOGGEDINUSER IS NULL! ##############");
                        hres.sendRedirect("Login.jsp");
                        return;
                    }else{
                      System.out.println("############## LOGGEDINUSER IS *NOT* NULL! ##############");
                    }
                } else if ((SessionBean1) session.getAttribute("SessionBean1") == null) {
                    System.out.println("############## SESSIONBEAN IS NULL! ##############");
                    hres.sendRedirect("Login.jsp");
                    return;
                }
            } catch (NullPointerException npe) {
                System.out.println("############## OH, CRAP! ############## " + npe);
            }

} else {
            System.out.println("############## PAGE IS LOGIN.JSP! ##############");
        }
        chain.doFilter(request, response);
    }

public void init(FilterConfig filterConfig) throws ServletException {
    }

public void destroy() {
    }
}

Thanks all!