欢迎访问我的博客,目前从事Machine Learning,欢迎交流

base64编码

 base64编码

复制代码
    var Base64 = {

        // private property
        _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

        // public method for encoding
        encode : function (input) {
            var output = "";
            var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
            var i = 0;

            input = Base64._utf8_encode(input);

            while (i < input.length) {

                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);

                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;

                if (isNaN(chr2)) {
                    enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                    enc4 = 64;
                }

                output = output +
                this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
                this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);

            }

            return output;
        },

        // public method for decoding
        decode : function (input) {
            var output = "";
            var chr1, chr2, chr3;
            var enc1, enc2, enc3, enc4;
            var i = 0;

            input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

            while (i < input.length) {

                enc1 = this._keyStr.indexOf(input.charAt(i++));
                enc2 = this._keyStr.indexOf(input.charAt(i++));
                enc3 = this._keyStr.indexOf(input.charAt(i++));
                enc4 = this._keyStr.indexOf(input.charAt(i++));

                chr1 = (enc1 << 2) | (enc2 >> 4);
                chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                chr3 = ((enc3 & 3) << 6) | enc4;

                output = output + String.fromCharCode(chr1);

                if (enc3 != 64) {
                    output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                    output = output + String.fromCharCode(chr3);
                }

            }

            output = Base64._utf8_decode(output);

            return output;

        },

        // private method for UTF-8 encoding
        _utf8_encode : function (string) {
            string = string.replace(/\r\n/g,"\n");
            var utftext = "";

            for (var n = 0; n < string.length; n++) {

                var c = string.charCodeAt(n);

                if (c < 128) {
                    utftext += String.fromCharCode(c);
                }
                else if((c > 127) && (c < 2048)) {
                    utftext += String.fromCharCode((c >> 6) | 192);
                    utftext += String.fromCharCode((c & 63) | 128);
                }
                else {
                    utftext += String.fromCharCode((c >> 12) | 224);
                    utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                    utftext += String.fromCharCode((c & 63) | 128);
                }

            }

            return utftext;
        },

        // private method for UTF-8 decoding
        _utf8_decode : function (utftext) {
            var string = "";
            var i = 0;
            var c = c1 = c2 = 0;

            while ( i < utftext.length ) {

                c = utftext.charCodeAt(i);

                if (c < 128) {
                    string += String.fromCharCode(c);
                    i++;
                }
                else if((c > 191) && (c < 224)) {
                    c2 = utftext.charCodeAt(i+1);
                    string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                    i += 2;
                }
                else {
                    c2 = utftext.charCodeAt(i+1);
                    c3 = utftext.charCodeAt(i+2);
                    string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                    i += 3;
                }

            }

            return string;
        }

    }
复制代码

 

posted @   有蚊子  阅读(193)  评论(0编辑  收藏  举报
编辑推荐:
· .NET制作智能桌面机器人:结合BotSharp智能体框架开发语音交互
· 软件产品开发中常见的10个问题及处理方法
· .NET 原生驾驭 AI 新基建实战系列:向量数据库的应用与畅想
· 从问题排查到源码分析:ActiveMQ消费端频繁日志刷屏的秘密
· 一次Java后端服务间歇性响应慢的问题排查记录
阅读排行:
· 互联网不景气了那就玩玩嵌入式吧,用纯.NET开发并制作一个智能桌面机器人(四):结合BotSharp
· 一个基于 .NET 开源免费的异地组网和内网穿透工具
· 《HelloGitHub》第 108 期
· Windows桌面应用自动更新解决方案SharpUpdater5发布
· 我的家庭实验室服务器集群硬件清单
点击右上角即可分享
微信分享提示