Validating when the user submits the form
, gather information from the form element to determine how to manage the submit process.
Both of these methods support numerous options which allows you to have full control over how the data is submitted.
The following picture depicts that workflow with Java servlet on the server side: To create a form in HTML we need to use the following tags:package net.codejava.servlet; import
Http Servlet Response; @Web Servlet("/login Servlet") public class Login Servlet extends Http Servlet Here’s an example output when submitting the above login form in browser: So far you have got the ins and outs when handling HTML form data with Java servlet.
Because, let’s face it, we don’t live in a perfect world, where everyone goes by your rules, or even knows them.
File input elements are automatically detected and processed for you.
So yeah, your users are going to skip some fields; enter emails without a ; use weak passwords; and not agree with the Terms of Service… We need to show the users what went wrong when they enter invalid data. What we do, then, is run this function when the form submitted, and if there are errors, we somehow reflect that in the UI. So imagine we have a sign up form, with three fields: name, email, and password.
In this post, we are going to look at the most basic way to do that. When that form is submitted, we want to make sure that: Nice!
A typical scenario is the user fills in fields of a form and submits it. Note that we use the - in the servlet set the value you want to transfer to the JSP page using the set Attribute() method on the request object.- in the JSP page, use the get Attribute() method on the request object to retrieve the value.
The server will process the request based on the submitted data, and send response back to the client. Servlet Exception; import javax.servlet.annotation. To transfer control from a servlet to a JSP page, use the Request Dispatcher() method.