how to get the base url from jsp request object?

How to get the base url from the jsp request object? http://localhost:8080/SOMETHING/index.jsp, but I want the part till index.jsp, how is it possible in jsp?


Solution 1:

So, you want the base URL? You can get it in a servlet as follows:

String url = request.getRequestURL().toString();
String baseURL = url.substring(0, url.length() - request.getRequestURI().length()) + request.getContextPath() + "/";
// ...

Or in a JSP, as <base>, with little help of JSTL:

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<c:set var="req" value="${pageContext.request}" />
<c:set var="url">${req.requestURL}</c:set>
<c:set var="uri" value="${req.requestURI}" />
...
<head>
    <base href="${fn:substring(url, 0, fn:length(url) - fn:length(uri))}${req.contextPath}/" />
</head>

Note that this does not include the port number when it's already the default port number, such as 80. The java.net.URL doesn't take this into account.

See also:

  • Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP

Solution 2:

JSP variant of Bozho's answer:

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="req" value="${pageContext.request}" />
<c:set var="baseURL" value="${req.scheme}://${req.serverName}:${req.serverPort}${req.contextPath}" />

Solution 3:

new URL(request.getScheme(), 
        request.getServerName(), 
        request.getServerPort(), 
        request.getContextPath());