how to get the base url from jsp request object?
How to ge开发者_如何学编程t 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?
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))}${req.contextPath}/" />
</head>
Note that this does not include the port number when it's already the default port number, such as 80. The java.net.URL doesn't take this into account.
See also:
- Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP
JSP variant of Bozho's answer:
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="req" value="${pageContext.request}" />
<c:set var="baseURL" value="${req.scheme}://${req.serverName}:${req.serverPort}${req.contextPath}" />
new URL(request.getScheme(),
request.getServerName(),
request.getServerPort(),
request.getContextPath());
There is one major flaw in @BalusC accepted answer though. Substring should start from 0 and not 1. Instead of
<base href="${fn:replace(req.requestURL, fn:substring(uri, 1, fn:length(uri)), req.contextPath)}" />
it should be
<base href="${fn:replace(req.requestURL, fn:substring(uri, 0, fn:length(uri)), req.contextPath)}" />
With 1 you get double forward slash: http://localhost:8080//appcontext/
With 0 you get, http://localhost:21080/appcontext/
In my application, request.getSession(false) always returned null when it was ending in double slash!!!
Instead of doing all of that, just do this:
request.getServerName().toString()
just use isSecure()
{<%=request.isSecure()?"https":"http:"%>}
加载中,请稍侯......
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