springboot正则表达式校验

String fileName = request.getParameter("fileName");
String datePath = request.getParameter("datePath").substring(0,10);
String fileUrl = PATH + datePath + "/";
String patternRole = "^[a-zA-Z0-9\\-]{32,40}.png$";
if (!Pattern.matches(patternRole, fileName)) {
    return null;
}