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Each web application contains a Session that can contain data that can be commonly made available to all the parts of the web application. The Session can be accessed from both the JSP and the Servlet.
Ex:
The servlet contains references to the HttpRequest object. So to access the session you can do so as below:
HttpSession session = request.getSession();
What else can I help you with?
What is difference between single threaded servlet and multi threaded servlet?
The single thread model means that your servlet would not be multi-threaded. If there are two concurrent requests to your servlet then 2 instances of your servlet will be created to process these 2 requests. You can implement the single thread model by implementing the SingleThreadModel interface in your class. This is just a marker interface and does not have any methods. The multi threaded model means that your servlet would be multi-threaded and only one instance would exist. Multiple concurrent requests would be served by the same instance but in different threads. You can implement the multi threaded model by not implementing the SingleThreadModel interface in your servlet class.
Difference between temporary servlet and permanent servlet?
A temporary servlet is started when a request arrives and shut down after the response is generated. A permanent servlet is loaded when the server is started and lives until the server is shut down. * This is useful when startup costs are high, such as a servlet that establishes a connection to a database. * Also useful for permanent serverside service, such as an RMI server. * Provides faster response to client requests when this is crucial. Being temporary or permanent is part of the server configuration.
What company uses a ten digit tracking number?
DHL and aramex.
How many times init method called if more then one instence are in servlet?
I have two questions how many times a method, modules or subroutines can be called? in most languages, how a variable is passed to a method?
How many digits in a fed ex tracking number?
How many digits in a fed referemce number?
What is servlet and why it is used?
servlet is a small program which run on serverside,and it can not be downloaded at client side. java servlets dynamically extends the functionalities of a web server. main use is: session tracking: no of users (unique) visited u'r website. in order to use cookies..
How many scope are there in servlet?
The two scopes are: Request & Session
How is statelessness of http overcome to run e-commerce applications on web?
it can be overcome by implementing session tracking & management in the running program on the server side. There are four solutions 1. Cookies, 2. Hidden from field, 3. URL rewriting and 4.Servlet Session API
What is session in jsp?
Session in the JSP and Servlet context refers to an instance of the HttpSession object that contains all the information about the current user session with the web application. This can be used as a cache or temporary storage area to store values that might be required across the application.
What are types of servlet?
Http servlet and Generic servlet
What is java servlet chaining?
Servlet Chaining means the output of one servlet act as a input to another servlet. Servlet Aliasing allows us to invoke more than one servlet in sequence when the URL is opened with a common servlet alias. The output from first Servlet is sent as input to other Servlet and so on. The Output from the last Servlet is sent back to the browser. The entire process is called Servlet Chaining.
What is a session What are the different ways of session tracking in servlet programming?
Why do we need a Session?When one page needs to share information with another, the scope of the data broadens beyond processing a single request. This is because, when a response gets committed, all the data that was held in the request that generated that response is destroyed. So, if you want that data in another page, you will be looking at a blank request object with no data in it. When such a need arises, you must send the data from one page to the server and from the server to the next requested page, whether it be the same page or another page altogether. There are several ways to share state information between requests. However, the primary or the easiest way is to use sessions.How Do Sessions Work?The container generates a session ID. When you create a session, the server saves the session ID on the client's machine as a cookie. If cookies are turned off then it appends the ID in the URL. On the server, whatever you add to the session object gets placed in server memory-very resource intensive. The server associates that object in memory with the session ID. When the user sends a new request, the session ID is sent too. The server can then match the objects in its memory with that session ID. This is how we maintain client state.
How do you dynamically identify the jsp in servlet?
You can dynamically identify the JSP file in a servlet by using the request URL or request parameters to determine which JSP to forward the request to. You can also store necessary information in session attributes or external configurations to help determine the appropriate JSP to display. Finally, you can use a servlet mapping or URL pattern to route requests to different JSP files based on the URL.
Set and get session attributes syntax in servlets and java script?
Setting and getting session attributes is fairly easy. It is the same in both Servlets and JSPs with one exception. In a JSP, you already have access to the session object, and you do not have to declare it. In a Servlet, you must get the session like this: javax.servlet.http.HttpSession session = request.getSession(); Once you have done that, you can set a session object like this: session.setAttribute("name","value"); To retrieve the value, do this: String foo = (String) session.getAttribute("name"); A couple of things to keep in mind: * The second parameter in the setAttribute method is an Object, not a String. When you retrieve the value, you have to cast it. In the example above, I am casting it to a String. * If you try to perform a getAttribute on a session attribute that does not exist, or was not set, it will return a null. * Session attributes are not available using JavaScript. You can not set or get an attribute in JavaScript. * You do NOT need to do the 'session = request.getSession() in a JSP. It is only necessary in a Servlet.
Can insert javascript coding in servlet?
No. Javascript code can be present inside a JSP but not inside a servlet. A Servlet is a pure java class.
What is servlet mapping?
A Servlet Mapping is a directive in the web.xml that tells the Servlet Container which class to use when a particular Servlet is called. A Servlet is a class within your Java Web Application. Let's say you have a servlet called MyServlet in the com.example.servlet package. You would need to have a Servlet Mapping pointing the path "/MyServlet" to the "com.example.servlet.MyServlet" class. Without the servlet mapping, you would not be able to invoke your servlet because the Servlet container would not know where it is. JSPs are different - they do not need mappings like this. JSPs exist within the WebRoot of the application, so they are always available. Servlets exist in the WEB-INF\Classes directory once your application is deployed.
How the pass value from the HTML pages to the servlet?
You need a form to pass value to a servlet. In the form tag, the action element passes the value into the servlet.
