6

I have some JavaScript that is making an Ajax call to a relative url (using jQuery).

var servletUrl = "someservlet";

$.ajax({
    type: "POST",
    url: servletUrl,
    success: function(response) {
        // ...
    }
});

Where "someservlet" is:

@WebServlet("/someservlet")
public class SomeServlet extends HttpServlet

I use this same script in multiple pages. When used from a page that is in the servlet context root, then the relative url resolves relative to the servlet context root, which is correct. When used from a page that is in a subfolder the URL resolves relative to the subfolder, which will return 404 error.

I would like to be able to reuse this JavaScript without having to modify it depending on the type of page that it is used within. Ideally, I need the equivalent of the JSTL's <c:url> tag. Is there anything in JavaScript that allows me to create URLs relative to the servlet context root?

BalusC
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KevinS
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1 Answers1

11

Several options:

  1. Set a HTML <base> element with that value (note: has its own advantages and disadvantages)

    <head>
    <base href="${pageContext.request.contextPath}/" />
    ...
</head>

    and then in JS:

    var contextPath = $("base").attr("href");
var servletUrl = contextPath + "someservlet";
// ...

  2. Or set a data attribute somewhere

    <html data-contextPath="${pageContext.request.contextPath}/">
    ...
</html>

    and then in JS:

    var contextPath = $("html").data("contextPath");
var servletUrl = contextPath + "someservlet";
// ...

  3. Or set a global JS variable with that value (poor practice):

    <head>
    ...
    <script>var contextPath = "${pageContext.request.contextPath}/";</script>
</head>

    and then in JS:

    var servletUrl = contextPath + "someservlet";
// ...
BalusC
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  • I tried your second option and it worked, with a little tweak. I had to modify the second substring parameter from 1 to 0 because it was giving me a URL with two slashes after the port number. That led to a 404 error. But with that little fix it worked great. Thanks very much. – KevinS Oct 07 '11 at 22:03