Why we need to use ServletContext attribute when we already have ServletContext parameters.Whats the difference between ServletContext Attributes and ServletContext parameters.
View RepliesI am making an application in which I have to make the model (the services) available to the entire application so that all beans can access it and call its methods during the life of the application.
I am using the following technologies:
view: JSF 2.x
beans: Spring 4.x beans
The design problem I am having is the following:I came up with the idea of registering the model services as ServletContext attributes using my ServletContextListener, effectively making the services available to the entire application:
//imports
public class MyContextListener implements ServletContextListener {
//model services
private UserService userService;
private RepairService repairService;
public void initCafe()
{
userService.removeAllUsers();
repairService.removeAllRepairs();
[code]....
Shouldn't I just use @Autowired userService and @Autowired repairservice everywhere I want to use these services application-wide?Or is this a problem because beans have a default scope of Request? I am confused.
How does the init() method in servlets have access to the servletContext . in its signature i can only see public void init(ServletConfig config) and init () . then how does it access servlet context .
View Replies View Relatedi am newbie to servlet and m working on a project like online shopping. I have list of data items in my database and i am able to fetch and display the data from database but i want to know that how can i store these data items in ServletContext so that i can use use it frequently in other pages.
View Replies View RelatedWhat is the difference between Attributes and Parameters.that is difference between two methods request.getAttribute() and request.getParameter() and why we have this two methods?
View Replies View RelatedI am building an application that has two types of users. While some of the fields (ie: username, email address, password) are the same for both user types, other fields are different for each user type.
Therefore, I would like to split up the process of registering (ie: writing the user info to database) into two parts:
1) registering the common fields among both user types (servlet 1)
2) registering the specific fields based on the user type that is registering (servlet 2a and servlet 2b).
Therefore, once servlet 1 is processed, I wish to forward the request to servlet 2a or 2b depending on what type of user is registering.
I wish to do this since I will have other parts of my application that will make use of servlets 2a and 2b as well. Is this possible to do (redirect request parameters from jsp to servlet and then to another servlet)?
Session attributes after logging into web-app:
Session Attributes
thisUsersAllowedRoles=45
username=hw
authenticatedUser=org.hw.client.payroll.model.User@2c8a09da
supervisorCode=
authenticated=true
[Code] ....
Every now and then while debugging I lose session attributes:
Session Attributes
thisUsersAllowedRoles=45
username=hw
supervisorCode=
authenticated=true
[Code] ....
The authenticatedUser and menu attributes are gone. I never know when it's going to happen so I can't trace it. Any guesses why those type session objects would die?
I attached an image of what menu object looks like.
I am trying to use three cookies in a servlet to store the background and foreground color and text size but my code is not working for some reason. When I run the servlet I get an IndexOutOfBounds exception and in my code is says my cookies are not ever used, when they should be to store the variables?
package httpServlets;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
[code]....
I am trying to make the variables that will be taken in from a type='text' box in HTML in NetBeans available to the other servlets as well as store and display the latest value passed into these boxes on the servlet page when the submit button is clicked or display null if the box has not yet received a value. However, I do not understand how to do this and do not understand as to why my current output is always null?
i) Is ServletContext().getAttribute("name of my textbox") really the way to pass the attributes to all servlets?
ii) Is ServletContext() passed in the service request?
iii) How to store the latest value passed into the submit box?
Here is my code
index.html
<html>
<head>
<title>Lab One</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
First Name: <input type="text" name="firstName">
[code]....
I'm a new Java user and I'm trying to code a simple login page. In first page (NewFile.jsp) users should enter their username and password and should click on "login", or click on "sign up".
1.) If user enters his username and password correctly, a login page (LoginPage.jsp) appears and says "welcome null" but it should show the name of that user instead of null.
2.) In that login page there is an edit button to edit profile information. When I clicked on it, every information is "null" and when I edit them and click on "Submit" button;
HTTP Status 404 -
type Status report
message
description The requested resource () is not available.
GlassFish Server Open Source Edition 3.1.2
that message appears.
3.) If I click on "Sign Up" button at the beginning, a registration jsp (SignUpPage.jsp) appears. After filling up text boxes and clicking on "Submit", same Status 404 screen appears.
I created a mysql database called "loginpage" using xampp. In that database there is a table called "users" and it has un, pass, name, surname, email and degree attributes.
Here is a screenshot of my project explorer:
Here is my code:
1. NewFile.jsp
<%@ page import="java.sql.*" %>
<%@ page import="java.io.*" %>
<%@ page import="java.util.*"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
[Code] .....
I have a web app that accepts requests. Once a request is sent, I want to create a thread that will sleep for several days if no user action is taken on the request to remind the user to do something. The problem is, how do I ensure the timer will pick up at the same place if the server is restarted? Would serializing the thread do that? I'm guessing no because I think you're just creating a new instance at start up. Just checking If there's anything built into Java to do this.
View Replies View RelatedI am using servlet 2.4 I used the ff. code below to set httponly in my application's cookies but it did not work. When I do a javascrip alert (document. cooke) in my page, the session id still shows up.
Cookie [] cookies = request.getCookies();
for(int x=0; x<cookies.length; x++){
Cookie cookie = (Cookie) cookies[x];
String cookieValue = cookie.getValue();
cookie.setValue(cookieValue + "; HttpOnly");
}
I also tried doing this and it wouldn't work too
String sessionid = request.getSession().getId();
response.setHeader("SET-COOKIE", "JSESSIONID=" + sessionid + "; HttpOnly");
by the way I am using an application server with its JAVA EE version = 1.4 and JAVA SE version = 5
What is the difference between JSESSION ID and Session?I red THIS blog, I got the explanation but I'm actually confused about JSESSION ID and Session.. In that blog, they told about JSESSION ID cookie. then What is the difference between JSESSION ID and Cookie?
View Replies View RelatedI would like getting a specific parameter name from the set of request parameters. In particular the name of the 4th parameter in the request parameter set.
View Replies View RelatedIs there anything in the HTML specification about whether submitted GET or POST parameters must retain their order? E.g. In the following is there anything in the spec that says the following data should be returned in the order they appear in the HTML code. And, most importantly, is there anything that says the firstName and surname fields should actually match up with each other, i.e. the order can change but in the same way for each field?
<form>
<table>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<tr><td><input type="text" name="firstName"/></td><td><input type="text" name="surname"/></td></tr>
<table>
</form>
In one jsp page, I submit a form with a message body with following html code (which is store in "MsgBody" in my request)
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
[code]....
But when I submit my form, I received in my servlet a parameter "MsgBody" without several tag like <html>/<body> ... do you know this behavior, by default tag are delete ?
public String execute(Map params, HttpServletRequest request, HttpServletResponse response) throws Exception {
String MsgBody = request.getParameter("MsgBody");.
I use Tomcat 7, maybe a tomcat behavior can influence for this tag loose in request param ?
I would like to use the attribute A of my class Selecter1, in my main class Resizing. How?
View Replies View RelatedI was practicing my java skills and came across an exercise in which a non parameter constructor calls a two parameter constructor. I tried a few searches online but they all came back unsuccessful. This is the part I am working on:
public PairOfDice(int val1, int val2) {
// Constructor. Creates a pair of dice that
// are initially showing the values val1 and val2.
die1 = val1; // Assign specified values
die2 = val2; // to the instance variables.
}
public PairOfDice() {
// Constructor that calls two parameter constructor
}
I tried calling the two constructor using the line "this(val1, val2)" but I get an error because val1 and val2 are local variables.
Then I tried to use the same signature: "this(int val1, int val2)" but that didn't work either.
We can have attributes in different scopes in a JSP page. Suppose there is an attribute named 'name' with values in different scopes as below:
request - A
session - B
application - C
page - D
Suppose I print ${name} in a JSP page, then what will be the value printed on the JSP? And, what will be the preference order of attributes search in different scopes?
I am new to Java and I am doing an assignment to identify Class and Attributes from below example. How to identify 7 classes and its attributes from this scenario:
ABC Maps Maker produces electronic maps for global positioning systems. Every map needs to define the latitude and longitude of the centre of the map, together with the length and breadth of the map. A map also has a name, and a set of geographical features.
A geographical feature is something noticeable in a a map; e.g., a hill, or valley. Among the types of features are the following: trace features, track features and tract features.
All features have a name that is displayed on the map next to the feature. A trace feature has a coordinate point to indicate its location relative to the centre of the map. Broadcasting stations, mountain peaks, and transmission towers, are examples of trace features. Every trace feature has a description associated with it.
Examples of track features include roads, railways and rivers. Each track feature has a list of points that define its course, and a line pattern. The line pattern specifies the colour, and the thickness.
Like a track feature, a tract feature also has set of points, except that when drawn on the map, the last point is linked to the first point to enclose a complete region. Additionally, it has a fill pattern which incorporates essentially a colour.
Recall that there is a class, Point, in the java.awt package – this can be used to hold the co-ordinate of a point
Class:
Attributes:
i have been trying to play around with System.out.printf , but it says that the method is not applicable to the attributes.below is my code :
package com.examples;
import java.util.Scanner;
public class Comparison {
public static void main(String[] args) {
Scanner input = new Scanner( System.in );
[code]....
On p.176 of EBJ 3 in Action (2nd edition),
MDS don't support all six transaction attributes. MDBs support only REQUIRE or NOT_SUPPORT.... There is no existing transaction to suspend or join when a message is delivered, The two options you have available are REQUIRE if you want a transaction.....
there is no existing transaction when a message is delivered from a queue to an MDB. Why we still need a transaction as it says " REQUIRE if you want a transaction"? When a message is delivered from the queue to the MDB, is this a transaction?
public class Employee {
private String firstName;
private String eeid;
}
I want to sort using empoyee firstName.. If two employee names are same, i need to sort based on eeid.. using insertion sort
if (key == "name") {
for (int i = 1; i < list.length; i++) {
Employee t = list[i];
int j;
for (j = i - 1; j >= 0 && t.getLastName().compareTo(list[j].getLastName())<0; j--)
list[j + 1] = list[j];
list[j + 1] = t;
}
}
It will sort using names.. But if two names are same, it wont sort based on eeid.. I want to achieve only using insertion sort..
EX:
vivek 8
broody 2
chari 3
vivek 5
chari 1
output:
broody 2
chari 1
chari 3
vivek 5
vivek 8
I have to create a new custom tag "imageLabeable" as a div contains a GraphicImage and an OutputLabel (primefaces).
Since I want to make it reusable as much as possible, I tried to write, in cc:interface section, all GraphicImage attributes (id, value, binding etc) and some new (GraphicImage is the main component among the two). But after that I have must associate GraphicImage attributes with the attributes created in cc:interface:
<cc:interface componentType="imageLabeable">
<cc:attribute name="value" />
<cc:attribute name="alt" />
<cc:attribute name="width" />
<cc:attribute name="height" />
[Code] .....
As you can see, if I have a lot of attributes I have to write a lot of association. Furthermore, if I see html rendered code with Firebug or similar, I see all of these associations.
Can I inherit these attributes automatically? Or associate it in easier way?
My code of start.xhtml is:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:f="http://xmlns.jcp.org/jsf/core">
[Code] .....
when I deploy the app(glassfish) I get this message only:
hi #{user.minimum} a #{user.maximum} .
Instead of a picture: wave.med.gif and message:
hi 0 a 10 .
file hierarchy is attached
In the servlet class I have:
String name = "James Bond";
Session.setAttribute("name", name);
Why is the attribute name and attribute value the same in all the books I've read. I know one is a string literal and one is an object but must it be the same?
Second thing I'm confused about... let's say I change the servlet code to
String name = "James Bond";
Session.setAttribute("hisname", name);
When I try to access it using JSP:
${sessionScope.name}
it works fine. So what is the point of the first argument in Session.setAttribute() ?