public static String getCleanParam(ServletRequest request, String paramName) {
        return StringUtils.clean(request.getParameter(paramName));
    }
Convenience method that returns a request parameter value, first running it through
{@link StringUtils#clean(String)}.

@param request   the servlet request.
@param paramName the parameter name.
@return the clean param value, or null if the param does not exist or is empty.
web/src/main/java/org/apache/shiro/web/util/WebUtils.java