利用Cookie防止刷新的在線考試倒計時JS代碼

JavaScript實現的Cookie防止刷新在線考試倒計時

$(function() {
            var _minute = parseInt("${exampaper.paperTime }");
            var _expiresHours = _minute  60  1000;


        if(!hasSetCookie()){
            addCookie("${examinee.examineeId}", _expiresHours, _expiresHours);
        } 
        settime($("#remainTime")); 
    });
    function hasSetCookie(){
        var strCookie = document.cookie;
        var arrCookie = strCookie.split("; ");
        for (var i = 0; i < arrCookie.length; i++) {
            var arr = arrCookie[i].split("=");
            if (arr[0] == "${examinee.examineeId}") {
                return true;
            }
        };
        return false;
    }
    //開始倒計時
    function settime(remainTime) {
        var _time = getCookieValue("871d31bacfd4451484c5f70f8860c2a9");
        var _countdown = parseInt(getCookieValue("${examinee.examineeId}")) / 1000;

        if (_countdown <= 0) {
            alert("考試時間到！");
            endExam();
        } else {
            var _second = _countdown % 60;
            var _minute = parseInt(_countdown / 60) % 60;
            var _hour = parseInt(parseInt(_countdown / 60) / 60);

            if (_hour < 10)
                _hour = "0" + _hour.toString();
            if (_second < 10)
                _second = "0" + _second.toString();
            if (_minute < 10)
                _minute = "0" + _minute.toString();

            remainTime.html(_hour + ":" + _minute + ":" + _second);
            _countdown--;
            editCookie("${examinee.examineeId}", _countdown * 1000, _countdown * 1000);
        }
        //每1000毫秒執行一次
        setTimeout(function() {
            settime(remainTime);
        }, 1000);
    };

    //時添加cookie
    function addCookie(name, value, expiresHours) {
        var cookieString = name + "=" + escape(value); //escape() 函數可對字符串進行編碼，這樣就可以在所有的計算機上讀取該字符串。
        //判斷是否設置過期時間,0代表關閉瀏覽器時失效
        if (expiresHours > 0) {
            var date = new Date();
            date.setTime(date.getTime() + expiresHours * 1000);
            cookieString = cookieString + ";expires=" + date.toUTCString();
        }
        document.cookie = cookieString;
    }

    //修改cookie的值
    function editCookie(name, value, expiresHours) {
        var cookieString = name + "=" + escape(value);
        if (expiresHours > 0) {
            var date = new Date();
            date.setTime(date.getTime() + expiresHours * 1000); //單位是毫秒
            cookieString = cookieString + ";expires=" + date.toGMTString();
        }
        document.cookie = cookieString;
    }

    //根據名字獲取cookie的值
    function getCookieValue(name) {
        var strCookie = document.cookie;
        var arrCookie = strCookie.split("; ");
        for (var i = 0; i < arrCookie.length; i++) {
            var arr = arrCookie[i].split("=");
            if (arr[0] == name) {
                return unescape(arr[1]);
                break;
            } else {
                continue;
            };
        };
    }</pre>