How does jsp create session when there're two requests coming simultaneously from the same client browser(maybe one tab maybe two tabs)?
I ask this question because it is said jsp could solve DuplicateSessionException in flex.
[URL] ....
if so, jsp would create same session(with same session id) for the two requests coming simultaneously?
May be I did not understand the meaning and usage of attribute "session" in page directive. My understanding is if session=false, in page directive, then the JSP page will not participate in the session. However, I have my welcomepage as below:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1" session="true"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
........
.......
<%= session %>
<c:out value="${pageContext.request.session}"/>
if I choose session=true, then both ways of accessing session works , which means the JSP page participated in the session.
But if I change the session=false, then <%= session %> fails, but <c:out value="${pageContext.request.session}"/> does not fail.
how can c:out still show the session, when session = false
When does HTTP Session object is created in web application. Suppose I have a website. Home page of website is HTTP page which contains details of company and link to Login page.
Consider below mentioned user journey as scenario:
a. user arrives at home page of website
b. user click on Login page
c. user fill in login details on login page and click on Submit
d. user is successfully authenticated and authorized from back end
e. User specific page is shown
f. user click on logout link
g. user is successfully logged out from website
h. user is redirected to home page
i. user closes browser
In the above mentioned user journey,
a. at which step does HTTP session starts (means at which steps does HTTP Session object is created ? )
b. at which step does HTTP session ends ?
In case required, assume tech stack to be Java 7, Servlet 2.5, JSP, Tomcat 7, Apache web server (for static web contents).....
I am trying to restrict the number of views in JSF 2.0.2 using
<context-param>
<param-name>org.apache.myfaces.NUMBER_OF_VIEWS_IN_SESSION</param-name>
<param-value>5</param-value>
</context-param>
In my case my managed bean is View Scoped and it supports a UI page which has multiple forms and each form is submitted as AJAX POST request.
As per the statndard, setting restriction to 5 should create 5 views and after that based on LRU algorithm the oldest views should get deleted if 6th views is created.
Therefore any action on the oldest view will throw the ViewExpiredException and i simply redirect the user to view expired page.
1) When i set the restriction to 5 views, i open 4 tabs with 3 forms each.
2) I submit the 3 forms on first tab everything works fine.
3) As soon as I go to 2nd tab and submit the first form thr, i get view expired exception
4) It seems I am exceeding the number of views I mentioned in web.xml
I want to know :
1) Does every AJAX POST submit itself creates a view ?
2) How I can count the number of views created in a session ?
3)Can i force expiry of a view in JSF 2.0.2 while the session is still alive ?
4) Normally JSF 2.0.2 session cachces the views. Lets assume session is alive the entire day but a view was created in morning at 9:00 AM and is not used again the entire day. Assuming that session doesn't reaches the max number of views it can save in entire day, will the view created in morning expire on its own after certain interval of time ? If not , can we still force its expiry while keeping the session alive ?
I have created a session handler in one class as below:
Session session = null;
Now, I want to use the same session handler in different class for creating channels. I don't want to create new session handler. How to do that?
It sounds simple enough, but I'm trying to implement a mechanism to prevent the same user logging into our distributed web application simultaneously.
So, given the scenario...
- user A logs in with username A
- user B logs in with username A
I want the logging in of username A by user B to invalidate the session for username A held by user A. So if people are sharing login credentials, the last person to log in kicks everyone else out who's logged in as that user.
The big problem I have is the application is deployed in a cluster across JVMs, so sessions are shared across nodes. My thought it to introduce a session listener to then inspect a table in the database which determines whether that user logged on - the part of identifying that is pretty simple as far as I can tell. The difficult part is kicking out the first user who logged in.
So, I guess my question is - can I invalidate an http session from with an MDB? If so my logic is to implement an MDB which listens on a topic and whenever a session is created that MDB checks for sessions belonging to the same user within that JVM to invalidate them (obviously skipping the JVM the login request came in on!).
Is that even possible? Is there a simpler way to do this?
I am working on an assignment, and I have come up with a program that runs, but it does not run correctly. This is the assignment:
Write two overloaded methods that return the average of an array with the following headers:
public static int average(int[] array)
public static double average(double[] array)
Write a test program that prompts the user to enter ten double values, invokes this method and displays the average value.
When I run it my averages are coming out incorrect, and I am not sure why. I have tried moving and rearranging things and nothing is working.
Java Code:
public static int average(int[] array) {
int sum = 0;
int average = 0;
[Code].....
I have a controller that on the basis of commands (formaction and subaction) dispatch requests to different jsp pages. But somehow when I am debugging my application, I can find duplicate request coming to the controller, so one jsp page does load twice. I am not sure from where the duplicate request is generating.
View Replies View RelatedI am making a shopping cart app in JSP and servlets to bring it all together. Finally.
I have a registration servlet (c1), a registration form jsp (c2), a login jsp (c3). c1 checks if a username is in the database or not.
If the username is not there, then register the user and send them to c3. I want c3 to display a "registration successful" message if a user has just registered successfully and is coming from c1. ELSE, take the user back to c2 with a message which tells them to choose a different username or password etc.
How do I implement the logic of showing a message depending on where a user is coming from ? The servlets and jsps are ready and I only need to add this logic for a custom message. Of course, I could make a JSP for Registration Successful and one for Registration Failure. But, that seems to be unnecessary.
Can I access the session object even session has been expired? I need to check whether session is expired or not for each request.The session invalidation is set null the session object. What I concluded, session time out I can access session object but session invalidation I can not access session object. How can I find the session time out by using session object?
View Replies View RelatedI have 2 war in 1 EAR.
War A corresponds to UI
War B corresponds to Rest
1) From War A, I login to the application and then fetch some users that is a rest call. I get the response back from rest in json form that ui consumes and display the data on page.
2) Now I click on the logout link from ui jsp. This logs out the session from Ui. I use <form data-dojo-type="dijit/form/Form" based logout.
3) I then go to the proxy (using burp) and manually request the rest call which I made in step no 1), the rest gives the response back with the same json object returned in step no 1) This shows that the logout action on step 2) is invalidated the session from War A (ui war) but the session or cookie based from WAR B (rest war) is not invalidated.
Expected outcome:After I Logout from War A(ui war), the session must also get invalidated from war B (rest war) and manually request from proxy should not get the same response object as received in step 1)
I am developing a e-commerce college project, here i add the items in the cart(a div tag in the jsp page) via servlet by creating sessions,
flow control: shopping jsp (when user wants to add an item in the cart) --> item servlet (which is used to create session and synchronized it) --> cart servlet(which is used to add items in the arraylist and show them in the shopping.jsp's div tag + it also sets the total purchase amount in the session variable "totalpurchase")
now after that user wants to proceed to checkout, here i use the onclick event to check the minimumshopping amount must be less than the totalpurchase (totalpurchase which i had setted in the session),but my jsp page is unable to rechognise the updated value of the totalpurchase, yes, if i reload the page, it rechognises the new updated value of the totalpurchase? but i want it to rechognise the updated total purchase value, without reloading he jsp page..
I did a Servlet and a JSP with a combobox. I called the JSP on one browser and selected value n1 from the combobox. From another computer, I called the (same URL) and selected value n2. I expected the Servlet to handled both requests separately, however when I select value n2 on the 2nd browser, the jsp on the 1st browser that initially had value 1, now changes into value 2 as well.
Why cant the servlet handle requests separately? users actions on different browsers should not interfere with each other..!
Generally Socket Programming uses HTTP Protocol to send and receive messages in Java. Can we try to exchange HTTP/HTTPS requests instead of TCP?
a Socket constructs a HTTP request to send to another socket from information it has and sends to another one and Server responds with HTTPResponse.
I want to write java code which can block unbuffered I/O requests send to CD driver ...
View Replies View RelatedI've written an HTTPServlet that send an HTTP request to one HttpListener and receive POST requests from an Http Sender.This is the code:
package sspa.huvr.git;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Date;
[code]...
but when is called from the doPost method it seems that the html content is not sent from the processRequest method.
Is it possible to send a duplicate soup request?Basically, I have a situation where two almost identical requests can get sent but right now the response comes back as one response. I wanted visibility to the two responses and the one gets dropped off
View Replies View RelatedI had to change context path name of my web application due to some organizational shuffle. I have successfully changed it and it has been working fine.
But what is happening is we have used old context path name in reminder and notification emails. so When users hit links from old emails, they are getting 404 Error.
Is there any way to redirect the old request which has old context path to new one?
Using Java 7 update 5 (I know it's old...), we are trying to send concurrent requests to a RMI Server. When we start to tamp up the load (not too much - up to 50 concurrent requests) we start to see many IO Problems like Broken Pipe and Connection Reset By Peer. Could we be hitting some unknown limitation on concurrent access? Is there such limitation?
View Replies View RelatedI have written the following code to handle multiple Client Request. Lets Assume that it takes server 300 nano seconds(ns) to process one connection request. It recieves two connection requests at time t1 and t1+200ns. Since server is busy handling request 1 at time t1+200ns. what will happen to request 2.if yes what is the max size of that buffer?Maximum number of request that a server process per unit time depends on the java code.Is there also a limit to how many request a server can recieve per unit time?
public class EchoServer
{
public static void main(String args[])
{
ServerSocket serverSocket = null;
BufferedReader readSocket = null;
PrintStream writeSocket = null;
serverSocket = new ServerSocket(9998);
[code]...
Is there any kind of way to generate HTTP request within a servlet, dispatch it to the server and get back the answer delivered to the servlet? Or are the servlets meant only to respond to passed requests, not generate them?
(I asked a similar question here: [Code] ..... but no luck)
String s= new String ("Hello");
String a = new String ("Hello");
As per my understanding the first line creates 2 objects : 1 for the heap memory and 1 for String pool
2nd line : new object created and no new object created in the String pool as the keyword already exists in the pool.
So the total number of objects created after the execution of 2 lines are : 3
I have tried this example ([URL].../) with CarDao extending the BaseDao, it works like a charm.However, from the CarDao class, my NetBeans underlined the class name “CarDao” with the error message “A session bean must not extend another session bean.” But I can compile, deploy and run the application without any problem.
I have also heard that a session bean cannot extend another session bean, but why it works here?
I am using Java EE 6, NetBeans 8.0.1 and WebLogic 12c for this code testing.
How should I access object, which I have created in servlet? Servlet handles the requests(controller) and forwards to requested jsp page.Some of the jsp pages need EJB objects. When i create an ejb object in servlet and then forward the request to jsp, how can i access the object in jsp ? This should be MVC - based application, like JSP-Servlet-EJB.
View Replies View RelatedIs it possible to have the value of an entered String to be set as the name of the String to be created whilst running.For example: String username= Keyboard.readString() & the user entered for example the word: "Hello".Is there a way how I can make the Java Program create another String named Hello (Inputted value of String username).
If this is allowed, what do I have to use and if possible show me exactly what I have to do with the example mentioned above?
cm2yOUa.jpg
Write a piece of code that would change something in the one of the buttons created using the loop? I have spent few hours reading about the arrays, different methods and can't think or apply a working solution.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class C2loops extends JFrame implements ActionListener {
private JButton jBTile, jBClicker;
private JPanel jPLeft, jPRight;
[Code] ....