Question

我写了这个小代码来处理cookies。但是，当我点击“下一步”按钮时，它会抛出一个
java.lang.NumberFormatException：对于输入字符串：“current”

代码：

<%@page import="java.util.*"%>
<%
int current=0;
Cookie[] cookies = request.getCookies();
Cookie cookie = null;
if(cookies != null){
    for(int i=0;i<cookies.length;i++){
        if(cookies[i].getName().equals("last"))
            cookie = cookies[i];    
        }
}

if(cookie != null){
    String btn = request.getParameter("button");
            if(btn != null){
                if(btn.equals("next"))
                    current = Integer.parseInt(cookie.getValue()) + 1;
                else
                    current = Integer.parseInt(cookie.getValue()) - 1;
            }
}
response.addCookie(new Cookie("last",String.valueOf("current")));
out.println(current);
%>
<html>
<head>
</head>

<body>
   <form method="post">    
       <input type="submit" name="button" value="prev" />
       <input type="submit" name="button" value="next" />
     </form>
</body>

</html>

Answer 1

您将Cookie设置为值"current"

String.valueOf("current")

但你想要

String.valueOf(current)

包含cookie的数字格式异常JSP页面

1 个答案: