An invalid character [44] was present in the Cookie value 

cookie中存在无效的字符character [44]，查询ASCII码表可知”44”表示逗号 

 ASCII码表

//list = c.getValue();

list=URLDecoder.decode(c.getValue(), "utf-8"); //解码

  // Cookie cookie = new Cookie("ListViewCookie",list);

 Cookie cookie=new Cookie("ListViewCookie",URLEncoder.encode(list, "utf-8"));//编码

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An invalid character [44] was present in the Cookie value 

cookie中存在无效的字符character [44]，查询ASCII码表可知”44”表示逗号 

首先报的异常是参数非法异常，异常信息是：在cookie值中存在一个无效字符。

所以可以检查下你的list是什么类型的,构造cookie对象时，两个参数必须是字符串。