Cookie中某些特殊字符的使用

时间：2025-03-23 09:37:43

今天学习Cookie对象的时候发现一个问题,跟着视频的代码敲,发现自己的代码运行时出现了问题.

HTTP Status 500

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

查阅了资料发现,Cookie对象的name和value属性中不可以包含空格和一下一些字符

[ ] ( ) = , " / ? @ : ;

如果需要保存的话,有个解决办法.使用URLEncoder的encode方法编码,使用时使用URLDecoder的decode方法解码.

两个方法都是传入字符串,以及编/解码使用的编码集.注意使用前千万要解码.容易忽视掉的就是循环内再次使用编码后的值.(其实是我自己忘了)

放今天学到使用到了特殊字符的代码

需求是点击之后会将图片添加到浏览记录中,并按最新浏览的显示在最前,删除记录会删除所有记录.

<%@ page import="" %>
<%@ page import="" %>
<%@ page contentType="text/html;charset=UTF-8" language="java"
         pageEncoding="UTF-8" %>
<html>
<head>
    <title>Title</title>
    <style type="text/css">
        .img1 {
            width: 160px;
            height: 120px;
        }

        .img2 {
            width: 60px;
            height: 45px;
        }

        .font {
            font-size: xx-small;
        }
    </style>
</head>
<body>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=1">手电筒</a>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=2">手机</a>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=3">电视</a><br/>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=4">冰箱</a>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=5">手表</a>
<img class="img1" src="/day11/img/"><a href="/day11/product?ID=6">笔记本</a>
<h3>浏览记录 <a href="/day11/remove" class="font">清除记录</a></h3>
<hr/>
<%
    Cookie cookie = ((), "product");
    if (cookie != null) {
        String value = ((), "UTF-8");
        String[] values = (",");
        for (int i =  - 1; i >= 0; i--) {
%>
<img class="img2" src="/day11/img/<%= values[i] %>.jpg">
<%
        }
    }
%>

</body>
</html>
package ;

import ;

import ;
import ;
import ;
import ;
import ;
import ;
import ;

public class ProductServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        //获取传过来ID的值
        String id = ("ID");
        //获取cookie数组
        Cookie[] cookies = ();
        //通过cookie名称获取cookie对象
        Cookie cookie = (cookies, "product");
        //判断cookie是否为空
        if (cookie == null) {
            //如果第一次访问,添加新的cookie
            (new Cookie("product", id));
        } else {
            String value = ();
            //注意操作之前需要解码
            value = (value, "UTF-8");
            //不是第一次,获取每个id的值
            String[] ids = (",");
            if (checkID(ids, id)) {
                //创建StringBuilder对象便于修改字符串
                //以下目的是将已有的id值删除,以达到所有都能按顺序添加进去
                StringBuilder sb = new StringBuilder(value);
                int index = ("," + id);
                if (index != -1) {
                    (index, index + 2);
                }else if((id)!=-1){
                    (0,2);
                }
                //最后转为字符串
                value=();
            }
            String newStr = (value + "," + id, "UTF-8");
            (newStr);
            (cookie);
        }
        ("/day11/jsp/");
    }

    //查询ids中是否包含id
    private boolean checkID(String[] ids, String id) {
        for (String tmp : ids) {
            if ((tmp)) {
                return true;
            }
        }
        return false;
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        doGet(req, resp);
    }
}
package ;

import ;

public class MyCookieUtil {
    public static Cookie getCookieByName(Cookie[] cookies, String name) {
        if (cookies == null) {
            return null;
        } else {
            for (Cookie cookie : cookies) {
                if (().equals(name)) {
                    return cookie;
                }
            }
            return null;
        }
    }
}
package ;

import ;
import ;
import ;
import ;
import ;
import ;

public class RemoveCookieServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie cookie = new Cookie("product", "");
        (0);
        (cookie);
        ("/day11/jsp/");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}


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