如何使用Java代码检查客户端浏览器中是否启用了JavaScript

Question

谁能帮助我尝试检查是否使用Java代码在客户端浏览器中启用了JavaScript。

Answer 1

假设您正在编写Java
Web应用程序，我成功使用的一种技术是让访问的第一页（通常是登录表单）在页面加载时编写会话cookie。然后，获取表单提交的Java代码以检查该cookie的存在。

在客户端上：

<script type="text/javascript">
  function createCookie(name, value, days) {
    var expires = "";
    if (days) {
      var date = new Date();
      date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
      expires = "; expires=" + date.toGMTString();
    }
    var cookie = name + "=" + value + expires + "; path=" + "/";
    document.cookie = cookie;
  }
  createCookie("JavaScriptEnabledCheck", 1, 0);
</script>

在服务器上：

/**
 * Returns <code>true</code> if the session cookie set by the login form
 * is not present.
 * 
 * @param request The HTTP request being processed
 * @return <code>true</code> if JavaScript is disabled, otherwise <code>false</code>
 */
private boolean isJavaScriptDisabled(HttpServletRequest request)
{
  boolean isJavaScriptDisabled = true;
  Cookie[] cookies = request.getCookies();

  if (cookies != null)
  {
    for (int i = 0; i < cookies.length; i++)
    {
      if ("JavaScriptEnabledCheck".equalsIgnoreCase(cookies[i].getName()))
      {
        isJavaScriptDisabled = false;
        break;
      }
    }
  }

  return isJavaScriptDisabled;
}