如何获得基本URL？ [英] How get the base URL?

问题描述

我有这样的结构：

WebContent
    resources
        components
            top.xhtml

    company
        about_us.xhtml

    index.xhtml

top.xhtml 是一个组件，用于 index.xthml 和 about_us.xhtml 。

top.xhtml is a component, that is used in index.xthml and about_us.xhtml too.

top.xhtml

<ul>
    <li><a href="index.xhtml">Home</a></li>
    <li><a href="company/about_us.xhtml">About us</a></li>
    ...
</ul>

所以我的问题是，当前页面是 index.xhtml 该组件正确生成URL，但当当前页面为 about_us.xhtml 时，它会生成错误的URL。我不能使用相对路径，因为它也会生成错误的URL。我认为这是因为该组件基于 *。xhtml 页面的当前路径。

So my problem is, when the current page is index.xhtml the component generates URLs correctly, but when the current page is about_us.xhtml, it generates wrong URLs. I cannot use relative path because it's going to generate the wrong URL too. I think it is because the component is based on the current path of the *.xhtml page.

唯一我能找到的解决方案是：

The only solution I could found out is:

<ul>
    <li><a href="${pageContext.request.contextPath}/webname/index.xhtml">Home</a></li>
    <li><a href="${pageContext.request.contextPath}/webname/about_us.xhtml">About us</a></li>
    ...
</ul>

但我认为根本不是'优雅'。任何想法？

But I think is not 'elegant' at all. Any ideas?

推荐答案

根据服务器端的文件结构不能解析URL。根据相关资源的真实公共网址解析URL。这就是网页浏览器必须调用它们，而不是网络服务器。

URLs are not resolved based on the file structure in the server side. URLs are resolved based on the real public web addresses of the resources in question. It's namely the webbrowser who has got to invoke them, not the webserver.

有几种方法可以缓解疼痛：

There are several ways to soften the pain:

JSF EL提供 $ {pageContext.request} 的简写，其风格为＃{request} ：

JSF EL offers a shorthand to ${pageContext.request} in flavor of #{request}:

<li><a href="#{request.contextPath}/index.xhtml">Home</a></li>
<li><a href="#{request.contextPath}/about_us.xhtml">About us</a></li>

如有必要，您可以使用 < c：set> 标记到让它更短。把它放在主模板的某个地方，它将可用于所有页面：

You can if necessary use <c:set> tag to make it yet shorter. Put it somewhere in the master template, it'll be available to all pages:

<c:set var="root" value="#{request.contextPath}/" />
...
<li><a href="#{root}index.xhtml">Home</a></li>
<li><a href="#{root}about_us.xhtml">About us</a></li>

JSF 2.x提供< h：link> 可以在结果中获取相对于上下文根的视图ID，它将附加上下文路径和 FacesServlet 自动映射：

JSF 2.x offers the <h:link> which can take a view ID relative to the context root in outcome and it will append the context path and FacesServlet mapping automatically:

<li><h:link value="Home" outcome="index" /></li>
<li><h:link value="About us" outcome="about_us" /></li>

HTML提供 < base> 标记，它使文档中的所有相对URL相对于此基础。你可以利用它。把它放在< h：head> 。

<base href="#{request.requestURL.substring(0, request.requestURL.length() - request.requestURI.length())}#{request.contextPath}/" />
...
<li><a href="index.xhtml">Home</a></li>
<li><a href="about_us.xhtml">About us</a></li>

（注意：这需要EL 2.2，否则你最好使用JSTL fn：substring（），另见这个答案）

(note: this requires EL 2.2, otherwise you'd better use JSTL fn:substring(), see also this answer)

这应该最终生成的HTML类似于

This should end up in the generated HTML something like as

<base href="http://example.com/webname/" />

请注意< base> 标记有一个警告：它使页面中的所有跳跃锚点像< a href =＃top> 相对于它！另请参见建议使用<基> html标签？在JSF中你可以解决它，如< a href =＃{request.requestURI} #top> top< / a> 或< h：link value =topfragment =top/> 。

Note that the <base> tag has a caveat: it makes all jump anchors in the page like <a href="#top"> relative to it as well! See also Is it recommended to use the <base> html tag? In JSF you could solve it like <a href="#{request.requestURI}#top">top</a> or <h:link value="top" fragment="top" />.

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