由於之前出現錯誤：java.lang.IllegalArgumentException: Control character in cookie value or attribute.

是編碼問題造成的。

故先在寫入cookie時進行編碼：URLEncoder.encode(name, "utf-8");
再在從cookie中讀出時解碼：URLDecoder.decode(co.getValue(), "utf-8");

之前寫入cookie的程式碼：

//將name儲存到cookie中
Cookie nameCookie=new Cookie("userName",name);
//新增cookie
response.addCookie(nameCookie);
 

for (Cookie co : cookies) {
                String cookieName = co.getName();
                if (cookieName.equals("userName")) {
                    name = co.getValue();
                }
            }

//將name儲存到cookie中
String urlName=URLEncoder.encode(name, "utf-8");
Cookie nameCookie=new Cookie("userName",urlName);
//新增cookie
response.addCookie(nameCookie);
 

更改後讀取cookie的程式碼：

for (Cookie co : cookies) {
                String cookieName = co.getName();
                if (cookieName.equals("userName")) {
                    name =  URLDecoder.decode(co.getValue(), "utf-8");
                }
            }