Good evening,
In a test JSF 2.0 web app, I am trying to get the number of active sessions but there is a problem in the sessionDestroyed method of the HttpSessionListener. Indeed, when a user logs in, the number of active session increases by 1, but when a user logs off, the same number remains as it is (no desincrementation happens) and the worse is that, when the same user logs in again (even though he unvalidated the session), the same number is incremented. To put that in different words :
1- I log in, the active sessions number is incremented by 1. 2- I Logout (the session gets unvalidated) 3- I login again, the sessions number is incremented by 1. The display is = 2. 4- I repeat the operation, and the sessions number keeps being incremented, while there is only one user logged in.
So I thought that method sessionDestroyed is not properly called, or maybe effectively called after the session timeout which is a parameter in WEB.XML (mine is 60 minutes). That is weird as this is a Session Listener and there is nothing wrong with my Class.
Does someone please have a clue?
package mybeans;
import entities.Users;
import java.io.*;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.bean.ManagedBean;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import jsf.util.JsfUtil;
/**
* Session Listener.
* @author TOTO
*/
@ManagedBean
public class SessionEar implements HttpSessionListener {
public String ctext;
File file = new File("sessionlog.csv");
BufferedWriter output = null;
public static int activesessions = 0;
public static long creationTime = 0;
public static int remTime = 0;
String separator = ",";
String headtext = "Session Creation Time" + separator + "Session Destruction Time" + separator + "User";
/**
*
* @return Remnant session time
*/
public static int getRemTime() {
return remTime;
}
/**
*
* @return Session creation time
*/
public static long getCreationTime() {
return creationTime;
}
/**
*
* @return System time
*/
private String getTime() {
return new Date(System.currentTimeMillis()).toString();
}
/**
*
* @return active sessions number
*/
public static int getActivesessions() {
return activesessions;
}
@Override
public void sessionCreated(HttpSessionEvent hse) {
// Insert value of remnant session time
remTime = hse.getSession().getMaxInactiveInterval();
// Insert value of Session creation time (in seconds)
creationTime = new Date(hse.getSession().getCreationTime()).getTime() / 1000;
if (hse.getSession().isNew()) {
activesessions++;
} // Increment the session number
System.out.println("Session Created at: " + getTime());
// We write into a file information about the session created
ctext = String.valueOf(new Date(hse.getSession().getCreationTime()) + separator);
String userstring = FacesContext.getCurrentInstance().getExternalContext().getRemoteUser();
// If the file does not exist, create it
try {
if (!file.exists()) {
file.createNewFile();
output = new BufferedWriter(new FileWriter(file.getName(), true));
// output.newLine();
output.write(headtext);
output.flush();
output.close();
}
output = new BufferedWriter(new FileWriter(file.getName(), true));
//output.newLine();
output.write(ctext + userstring);
output.flush();
output.close();
} catch (IOException ex) {
Logger.getLogger(SessionEar.class.getName()).log(Level.SEVERE, null, ex);
JsfUtil.addErrorMessage(ex, "Cannot append session Info to File");
}
System.out.println("Session File has been written to sessionlog.txt");
}
@Override
public void sessionDestroyed(HttpSessionEvent se) {
// Desincrement the active sessions number
activesessions--;
// Appen Infos about session destruction into CSV FILE
String stext = "\n" + new Date(se.getSession().getCreationTime()) + separator;
try {
if (!file.exists()) {
file.createNewFile();
output = new BufferedWriter(new FileWriter(file.getName(), true));
// output.newLine();
output.write(headtext);
output.flush();
output.close();
}
output = new BufferedWriter(new FileWriter(file.getName(), true));
// output.newLine();
output.write(stext);
output.flush();
output.close();
} catch (IOException ex) {
Logger.getLogger(SessionEar.class.getName()).log(Level.SEVERE, null, ex);
JsfUtil.addErrorMessage(ex, "Cannot append session Info to File");
}
}
} // END OF CLASS
I am retrieving the active sessions number this way:
<h:outputText id="sessionsfacet" value="#{UserBean.activeSessionsNumber}"/>
from another managedBean:
public String getActiveSessionsNumber() {
return String.valueOf(SessionEar.getActivesessions());
}
My logout method is as follow:
public String logout() {
HttpSession lsession = (HttpSession) FacesContext.getCurrentInstance().getExternalContext().getSession(false);
if (lsession != null) {
lsession.invalidate();
}
JsfUtil.addSuccessMessage("You are now logged out.");
return "Logout";
}
// end of logout
