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How to use relative paths without including the context root name?

开发者 https://www.devze.com 2023-02-05 21:01 出处:网络
To working my static file (CSS, JS) I have to write absolute path like /AppName/templates/style/main.css. Is there any solution, that I could write relative path like style/mai开发者_高级运维n.css?If

To working my static file (CSS, JS) I have to write absolute path like /AppName/templates/style/main.css. Is there any solution, that I could write relative path like style/mai开发者_高级运维n.css?


If your actual concern is the dynamicness of the webapp context (the "AppName" part), then just retrieve it dynamically by HttpServletRequest#getContextPath().

<head>
    <link rel="stylesheet" href="${pageContext.request.contextPath}/templates/style/main.css" />
    <script src="${pageContext.request.contextPath}/templates/js/main.js"></script>
    <script>var base = "${pageContext.request.contextPath}";</script>
</head>
<body>
    <a href="${pageContext.request.contextPath}/pages/foo.jsp">link</a>
</body>

If you want to set a base path for all relative links so that you don't need to repeat ${pageContext.request.contextPath} in every relative link, use the <base> tag. Here's an example with help of JSTL functions.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
...
<head>
    <c:set var="url">${pageContext.request.requestURL}</c:set>
    <base href="${fn:substring(url, 0, fn:length(url) - fn:length(pageContext.request.requestURI))}${pageContext.request.contextPath}/" />
    <link rel="stylesheet" href="templates/style/main.css" />
    <script src="templates/js/main.js"></script>
    <script>var base = document.getElementsByTagName("base")[0].href;</script>
</head>
<body>
    <a href="pages/foo.jsp">link</a>
</body>

This way every relative link (i.e. not starting with / or a scheme) will become relative to the <base>.

This is by the way not specifically related to Tomcat in any way. It's just related to HTTP/HTML basics. You would have the same problem in every other webserver.

See also:

  • Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP
  • Is it recommended to use the <base> html tag?


Just use <c:url>-tag with an application context relative path.

When the value parameter starts with an /, then the tag will treat it as an application relative url, and will add the application-name to the url. Example:

jsp:

<c:url value="/templates/style/main.css" var="mainCssUrl" />`
<link rel="stylesheet" href="${mainCssUrl}" />
...
<c:url value="/home" var="homeUrl" />`
<a href="${homeUrl}">home link</a>

will become this html, with an domain relative url:

<link rel="stylesheet" href="/AppName/templates/style/main.css" />
...
<a href="/AppName/home">home link</a>


You start tomcat from some directory - which is the $cwd for tomcat. You can specify any path relative to this $cwd.

suppose you have

home
- tomcat
 |_bin
- cssStore
 |_file.css

And suppose you start tomcat from ~/tomcat, using the command "bin/startup.sh".

~/tomcat becomes the home directory ($cwd) for tomcat

You can access "../cssStore/file.css" from class files in your servlet now

Hope that helps, - M.S.


Instead using entire link we can make as below (solution concerns jsp files)

With JSTL we can make it like: To link resource like css, js:

     <link rel="stylesheet" href="${pageContext.request.contextPath}/style/sample.css" />
     <script src="${pageContext.request.contextPath}/js/sample.js"></script>   

To simply make a link:

     <a id=".." class=".." href="${pageContext.request.contextPath}/jsp/sample.jsp">....</a>

It's worth to get familiar with tags

   <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

There is also jsp method to do it like below, but better way like above:

   <link rel="stylesheet" href="<%=request.getContextPath()%>/style/sample.css" />
   <script type="text/javascript" src="<%=request.getContextPath()%>/js/sample.js"></script>

To simply make a link:

   <a id=".." class=".." href="<%=request.getContextPath()%>/jsp/sample.jsp">....</a>


This could be done simpler:

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

All URL will be formed without unnecessary domain:port but with application context.


This is a derivative of @Ralph suggestion that I've been using. Add the c:url to the top of your JSP.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:url value="/" var="root" />

Then just reference the root variable in your page:

<link rel="stylesheet" href="${root}templates/style/main.css">
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