storage.js

// 检测是否为隐私模式
function isLocalStorageNameSupported() {
    var testKey = 'test', storage = window.localStorage;
    try {
        storage.setItem(testKey, '1');
        storage.removeItem(testKey);
        return true;
    } catch (error) {
        return false;
    }
}

// 如果不存在或不可用（隐私模式下不可用会报错）
if (!isLocalStorageNameSupported() || !window.localStorage) {
    console.log('重新定义localStorage')
    window.storage = new (function () {
        var aKeys = [], oStorage = {};
        Object.defineProperty(oStorage, "getItem", {
          value: function (sKey) { return sKey ? this[sKey] : null; },
          writable: false,
          configurable: false,
          enumerable: false
        });
        Object.defineProperty(oStorage, "key", {
          value: function (nKeyId) { return aKeys[nKeyId]; },
          writable: false,
          configurable: false,
          enumerable: false
        });
        Object.defineProperty(oStorage, "setItem", {
          value: function (sKey, sValue) {
            if(!sKey) { return; }
            document.cookie = escape(sKey) + "=" + escape(sValue) + "; expires=Tue, 19 Jan 2038 03:14:07 GMT; path=/";
          },
          writable: false,
          configurable: false,
          enumerable: false
        });
        Object.defineProperty(oStorage, "length", {
          get: function () { return aKeys.length; },
          configurable: false,
          enumerable: false
        });
        Object.defineProperty(oStorage, "removeItem", {
          value: function (sKey) {
            if(!sKey) { return; }
            document.cookie = escape(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/";
          },
          writable: false,
          configurable: false,
          enumerable: false
        });
        this.get = function () {
          var iThisIndx;
          for (var sKey in oStorage) {
            iThisIndx = aKeys.indexOf(sKey);
            if (iThisIndx === -1) { oStorage.setItem(sKey, oStorage[sKey]); }
            else { aKeys.splice(iThisIndx, 1); }
            delete oStorage[sKey];
          }
          for (aKeys; aKeys.length > 0; aKeys.splice(0, 1)) { oStorage.removeItem(aKeys[0]); }
          for (var aCouple, iKey, nIdx = 0, aCouples = document.cookie.split(/\s*;\s*/); nIdx < aCouples.length; nIdx++) {
            aCouple = aCouples[nIdx].split(/\s*=\s*/);
            if (aCouple.length > 1) {
              oStorage[iKey = unescape(aCouple[0])] = unescape(aCouple[1]);
              aKeys.push(iKey);
            }
          }
          return oStorage;
        };
        this.configurable = false;
        this.enumerable = true;
        return oStorage;
    })()
} else {
    window.storage = window.localStorage
};