如何从cookie创建和读取值？-Java 学习之路

223

如何在JavaScript中创建和读取cookie中的值？

16 回答

以下是可用于创建和检索Cookie的函数 .

var createCookie = function(name, value, days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        expires = "; expires=" + date.toGMTString();
    }
    else {
        expires = "";
    }
    document.cookie = name + "=" + value + expires + "; path=/";
}

function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) {
                c_end = document.cookie.length;
            }
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}

回复于 2024-04-30T06:09:17+08:00

JQuery Cookies

或普通的Javascript：

function setCookie(c_name,value,exdays)
{
   var exdate=new Date();
   exdate.setDate(exdate.getDate() + exdays);
   var c_value=escape(value) + ((exdays==null) ? "" : ("; expires="+exdate.toUTCString()));
   document.cookie=c_name + "=" + c_value;
}

function getCookie(c_name)
{
   var i,x,y,ARRcookies=document.cookie.split(";");
   for (i=0; i<ARRcookies.length; i++)
   {
      x=ARRcookies[i].substr(0,ARRcookies[i].indexOf("="));
      y=ARRcookies[i].substr(ARRcookies[i].indexOf("=")+1);
      x=x.replace(/^\s+|\s+$/g,"");
      if (x==c_name)
      {
        return unescape(y);
      }
   }
}

回复于 2024-04-30T06:09:17+08:00

简约和全功能的ES6方法：

const setCookie = (name, value, days = 7, path = '/') => {
  const expires = new Date(Date.now() + days * 864e5).toUTCString()
  document.cookie = name + '=' + encodeURIComponent(value) + '; expires=' + expires + '; path=' + path
}

const getCookie = (name) => {
  return document.cookie.split('; ').reduce((r, v) => {
    const parts = v.split('=')
    return parts[0] === name ? decodeURIComponent(parts[1]) : r
  }, '')
}

const deleteCookie = (name, path) => {
  setCookie(name, '', -1, path)
}

回复于 2024-04-30T06:09:17+08:00

Mozilla提供了simple framework for reading and writing cookies with full unicode support以及如何使用它的示例 .

一旦包含在页面上，您就可以设置一个cookie：

docCookies.setItem(name, value);

读一个cookie：

docCookies.getItem(name);

或删除cookie：

docCookies.removeItem(name);

例如：

// sets a cookie called 'myCookie' with value 'Chocolate Chip'
docCookies.setItem('myCookie', 'Chocolate Chip');

// reads the value of a cookie called 'myCookie' and assigns to variable
var myCookie = docCookies.getItem('myCookie');

// removes the cookie called 'myCookie'
docCookies.removeItem('myCookie');

查看有关Mozilla's document.cookie page的更多示例和详细信息 .

回复于 2024-04-30T06:09:17+08:00

我是一段很棒的代码：简单易用 . 但我通常使用babel和ES6以及模块，所以如果你像我一样，这里是复制的代码，以便用ES6更快地开发

Accepted answer用ES6重写为模块：

export const createCookie = ({name, value, days}) => {
  let expires;
  if (days) {
    let date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    expires = '; expires=' + date.toGMTString();
  } else {
    expires = '';
  }
  document.cookie = name + '=' + value + expires + '; path=/';
};

export const getCookie = ({name}) => {
  if (document.cookie.length > 0) {
    let c_start = document.cookie.indexOf(name + '=');
    if (c_start !== -1) {
      c_start = c_start + name.length + 1;
      let c_end = document.cookie.indexOf(';', c_start);
      if (c_end === -1) {
        c_end = document.cookie.length;
      }
      return unescape(document.cookie.substring(c_start, c_end));
    }
  }
  return '';
};

在此之后，您可以将其导入为任何模块（当然路径可能会有所不同）：

import {createCookie, getCookie} from './../helpers/Cookie';

回复于 2024-04-30T06:09:17+08:00

对于那些需要像{foo：'bar'}这样的保存对象的人，我分享了@ KevinBurke答案的编辑版本 . 我添加了JSON.stringify和JSON.parse，这就是全部 .

cookie = {

    set: function (name, value, days) {
        if (days) {
            var date = new Date();
            date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
            var expires = "; expires=" + date.toGMTString();
        }
        else
            var expires = "";
        document.cookie = name + "=" + JSON.stringify(value) + expires + "; path=/";
    },

    get : function(name){
        var nameEQ = name + "=",
            ca = document.cookie.split(';');

        for(var i=0;i < ca.length;i++) {
          var c = ca[i];
          while (c.charAt(0)==' ') c = c.substring(1,c.length);
            if (c.indexOf(nameEQ) == 0) 
              return  JSON.parse(c.substring(nameEQ.length,c.length));
        }

        return null;
    }

}

所以，现在你可以做这样的事情：

cookie.set('cookie_key', {foo: 'bar'}, 30);

cookie.get('cookie_key'); // {foo: 'bar'}

cookie.set('cookie_key', 'baz', 30);

cookie.get('cookie_key'); // 'baz'

回复于 2024-04-30T06:09:17+08:00

208

这是Get, Set and Delete Cookie in JavaScript的代码 .

function getCookie(name) {
    name = name + "=";
    var cookies = document.cookie.split(';');
    for(var i = 0; i <cookies.length; i++) {
        var cookie = cookies[i];
        while (cookie.charAt(0)==' ') {
            cookie = cookie.substring(1);
        }
        if (cookie.indexOf(name) == 0) {
            return cookie.substring(name.length,cookie.length);
        }
    }
    return "";
}

function setCookie(name, value, expirydays) {
 var d = new Date();
 d.setTime(d.getTime() + (expirydays*24*60*60*1000));
 var expires = "expires="+ d.toUTCString();
 document.cookie = name + "=" + value + "; " + expires;
}

function deleteCookie(name){
  setCookie(name,"",-1);
}

资料来源：http://mycodingtricks.com/snippets/javascript/javascript-cookies/

回复于 2024-04-30T06:09:17+08:00

-1

我用这个对象 . 值是编码的，因此在从服务器端读取或写入时需要考虑它 .

cookie = (function() {

/**
 * Sets a cookie value. seconds parameter is optional
 */
var set = function(name, value, seconds) {
    var expires = seconds ? '; expires=' + new Date(new Date().getTime() + seconds * 1000).toGMTString() : '';
    document.cookie = name + '=' + encodeURIComponent(value) + expires + '; path=/';
};

var map = function() {
    var map = {};
    var kvs = document.cookie.split('; ');
    for (var i = 0; i < kvs.length; i++) {
        var kv = kvs[i].split('=');
        map[kv[0]] = decodeURIComponent(kv[1]);
    }
    return map;
};

var get = function(name) {
    return map()[name];
};

var remove = function(name) {
    set(name, '', -1);
};

return {
    set: set,
    get: get,
    remove: remove,
    map: map
};

})();

回复于 2024-04-30T06:09:17+08:00

39
ES7，使用正则表达式获取get（） . 基于MDN
```
const Cookie =
    { get: name => {
        let c = document.cookie.match(`(?:(?:^|.*; *)${name} *= *([^;]*).*$)|^.*$`)[1]
        if (c) return decodeURIComponent(c)
        }
    , set: (name, value, opts = {}) => { 
        if (opts.days) { 
            opts['max-age'] = opts.days * 60 * 60 * 24; 
            delete opts.days 
            }
        opts = Object.entries(opts).reduce((str, [k, v]) => `${str}; ${k}=${v}`, '')
        document.cookie = name + '=' + encodeURIComponent(value) + opts
        }
    , delete: (name, opts) => Cookie.set(name, '', {'max-age': -1, ...opts}) 
    // path & domain must match cookie being deleted 
    }
```
```
Cookie.set('user', 'Jim', {path: '/', days: 10}) 
// Set the path to top level (instead of page) and expiration to 10 days (instead of session)
```
用法 - Cookie.get（name，value [，options]）：
options支持所有标准cookie选项并添加"days"：
- path ：'/' - 任何绝对路径 . 默认值：当前文档位置，
- domain ：'sub.example.com' - 可能无法以点开头 . 默认值：没有子域的当前主机 .
- secure ：true - 仅通过https提供cookie . 默认值：false .
- days ：2天，直到cookie过期 . 默认值：会话结束 .
  设置过期的其他方法：
- expires ：'Sun, 18 Feb 2018 16:23:42 GMT' - 作为GMT字符串的到期日期 .
  当前日期可以使用：new Date（Date.now（）） . toUTCString（）
- 'max-age' ：30 - 与天相同，但以秒为单位而不是天 .
其他答案使用“expires”而不是“max-age”来支持旧的IE版本 . 这个方法需要ES7，所以IE7无论如何都是出局的（这不是什么大问题） .

注意：支持有趣的字符，如"="和""作为cookie值，正则表达式处理前导和尾随空格（来自其他库） .
如果您想存储对象，可以使用和JSON.stringify和JSON.parse之前和之后对它们进行编码，编辑上面的内容，或添加其他方法 . 例如：
```
Cookie.getJSON = name => JSON.parse(Cookie.get(name))
Cookie.setJSON = (name, value, opts) => Cookie.set(name, JSON.stringify(value), opts);
```
回复于 2024-04-30T06:09:17+08:00

-1

在ES6中读取cookie的简单方法 .

function getCookies() {
    var cookies = {};
    for (let cookie of document.cookie.split('; ')) {
        let [name, value] = cookie.split("=");
        cookies[name] = decodeURIComponent(value);
    }
    console.dir(cookies);
}

回复于 2024-04-30T06:09:17+08:00

-1

我用js-cookie来取得成功 .

<script src="/path/to/js.cookie.js"></script>
<script>
  Cookies.set('foo', 'bar');
  Cookies.get('foo');
</script>

回复于 2024-04-30T06:09:17+08:00

readCookie的改进版本：

function readCookie( name )
{
    var cookieParts = document.cookie.split( ';' )
    ,   i           = 0
    ,   part
    ,   part_data
    ,   value
    ;

    while( part = cookieParts[ i++ ] )
    {
        part_data = part.split( '=' );

        if ( part_data.shift().replace(/\s/, '' ) === name )
        {
            value = part_data.shift();
            break;
        }

    }
    return value;
}

一旦找到cookie值并返回其值，这应该会中断 . 在我看来，双重分裂非常优雅 .

if条件的替换是空白修剪，以确保它正确匹配

回复于 2024-04-30T06:09:17+08:00

-1

function setCookie(cname,cvalue,exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires=" + d.toGMTString();
    document.cookie = cname+"="+cvalue+"; "+expires;
}

function getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1);
        if (c.indexOf(name) == 0) {
            return c.substring(name.length, c.length);
        }
    }
    return "";
}

function checkCookie() {
    var user=getCookie("username");
    if (user != "") {
        alert("Welcome again " + user);
    } else {
       user = prompt("Please enter your name:","");
       if (user != "" && user != null) {
           setCookie("username", user, 30);
       }
    }
}

回复于 2024-04-30T06:09:17+08:00

-1

我编写了简单的cookieUtils，它有三个函数用于创建cookie，读取cookie和删除cookie .

var CookieUtils = {
    createCookie: function (name, value, expireTime) {
        expireTime = !!expireTime ? expireTime : (15 * 60 * 1000); // Default 15 min
        var date = new Date();
        date.setTime(date.getTime() + expireTime);
        var expires = "; expires=" + date.toGMTString();
        document.cookie = name + "=" + value + expires + "; path=/";
    },
    getCookie: function (name) {
        var value = "; " + document.cookie;
        var parts = value.split("; " + name + "=");
        if (parts.length == 2) {
            return parts.pop().split(";").shift();
        }
    },
    deleteCookie: function(name) {
        document.cookie = name +'=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
    }
};

回复于 2024-04-30T06:09:17+08:00

2
阅读cookie的一种厚颜无耻且简单的方法可能是：
```
let username, id; 
eval(document.cookie); 
console.log(username + ", " + id); // John Doe, 123
```
如果您知道您的cookie包含以下内容，则可以使用此选项： username="John Doe"; id=123; . 请注意，字符串在cookie中需要引号 . 可能不是推荐的方式，但适用于测试/学习 .
回复于 2024-04-30T06:09:17+08:00

以下是w3chools中提到的示例 .

function setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires="+ d.toUTCString();
    document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

function getCookie(cname) {
    var name = cname + "=";
    var decodedCookie = decodeURIComponent(document.cookie);
    var ca = decodedCookie.split(';');
    for(var i = 0; i <ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') {
            c = c.substring(1);
        }
        if (c.indexOf(name) == 0) {
            return c.substring(name.length, c.length);
        }
    }
    return "";
}

回复于 2024-04-30T06:09:17+08:00

如何从cookie创建和读取值？

16 回答

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