Util.java 文件源码

/** Utility methods
 * taken from org.apache.taglibs.standard.tag.common.core.UrlSupport
 */
public static String resolveUrl(
        String url, String context, PageContext pageContext)
throws JspException {
    // don't touch absolute URLs
    if (isAbsoluteUrl(url))
        return url;

    // normalize relative URLs against a context root
    HttpServletRequest request =
        (HttpServletRequest) pageContext.getRequest();
    if (context == null) {
        if (url.startsWith("/"))
            return (request.getContextPath() + url);
        else
            return url;
    } else {
        if (!context.startsWith("/") || !url.startsWith("/")) {
            throw new JspTagException(
            "In URL tags, when the \"context\" attribute is specified, values of both \"context\" and \"url\" must start with \"/\".");
        }
        if (context.equals("/")) {
            // Don't produce string starting with '//', many
            // browsers interpret this as host name, not as
            // path on same host.
            return url;
        } else {
            return (context + url);
        }
    }
}