Question

Since getJSON() method is used to get JSON data using an AJAX HTTP GET request.
Which method to use to get data from doPost method in servlet.
Say that I have used action to send the data to the servlet and want to get the response ..
Which JSON method to use..An example or a good tutorial would help

Thanks:)

Answer 1

So, you’re basically asking how to get JSON data by a POST request?

Instead of

$.getJSON('servleturl', function(data) {
    alert(data);
});

use

$.post('servleturl', function(data) {
    alert(data);
});

When you let the servlet do response.setContentType("application/json"), then the data is already in JSON format.

---

However, after reading your question and the comments once more, I think you’re basically asking how to submit a POST form using jQuery. This has essentially nothing to do with JSON (although the servlet can return a JSON response if desired).

Assuming the following form

<form id="formid" action="servleturl" method="post">
    <input type="text" name="foo" />
    <input type="text" name="bar" />
    <input type="submit" />
</form>

here’s how you can “ajaxify” it (do it during document ready!)

$('#formid').submit(function() {
    $form = $(this);
    $.post($form.attr('action'), $form.serialize(), function(data) {
        // Do something with response. Display message? Redirect to other page?
        alert(data);
    });
});

For another example also see this answer.

There exist plugins which do it more nicely, such as jQuery Form. It’s then as simple as

$('#formid').ajaxForm(function(data) {
    // Do something with response. Display message? Redirect to other page?
    alert(data);
});

and it also supports <input type="file"> elements without much trouble.