Submit form through Servlet

2
votes

Is there a way to create the Servlet (page display - form) and process it using the same Class?

If the browser requests http://mypage.com/TestServlet - then the form input page is displayed, and when the user submits the form, the same servlet action (../TestServlet) is called and it processes the input. I actually put the input processing logic in the doGet() method of the Servlet and now when I make a call to http://mypage.com/TestServlet , the logic is getting invoked automatically with null values. I know I can actually make a JSP or HTML page and then invoke the Servlet from there, but I don't want to. Is there a way to call a particular method of the Servlet? Like calling that method to process the user input when the Submit button is clicked and keeping the doGet() method to display the input form.

1
javaformsservlets

1 Answers

6
votes

Normal practice is to use doGet() to preprocess the form and doPost() to postprocess the form. You only need to ensure that you use <form method="post">. For an example, see our Servlet wiki page.

However, if you really need a GET form (so that the request is bookmarkable, like a search form) then you need to give the submit button a name-value pair and check in the servlet whether it is present as request parameter. E.g.

<input type="submit" name="search" value="Search" />

with the following in doGet().

if (request.getParameter("search") != null) {
    // Form is submitted.
} else {
    // Form is not submitted.
}