我写了这段处理Cookie的小代码。但是,当我单击“下一步”按钮时,它会抛出一个
java.lang.NumberFormatException:对于输入字符串:“当前”
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>
最佳答案
您将cookie设置为值"current"
String.valueOf("current")
但是你想要
String.valueOf(current)