一、base.js文件

javascript">const Base64 = function() {
  var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  this.encode = function(input) {
      var output = "";
      var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
      var i = 0;
      input = _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 +
              _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
              _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
      }
      return output;
  }

  this.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 = _keyStr.indexOf(input.charAt(i++));
          enc2 = _keyStr.indexOf(input.charAt(i++));
          enc3 = _keyStr.indexOf(input.charAt(i++));
          enc4 = _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 = _utf8_decode(output);
      return output;
  }

  var _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  
  var _utf8_decode = function (utftext) {
      var string = "";
      var i = 0;
      var c = 0;
      var c1 = 0;
      var c2 = 0;
      while (i < utftext.length) {    
          c = utftext.charCodeAt(i);
          if (c < 128) {
              string += String.fromCharCode(c);
              i++;
          } else if ((c > 191) && (c < 224)) {
              c1 = utftext.charCodeAt(i + 1);
              string += String.fromCharCode(((c & 31) << 6) | (c1 & 63));
              i += 2;
          } else {
              c1 = utftext.charCodeAt(i + 1);
              c2 = utftext.charCodeAt(i + 2);
              string += String.fromCharCode(((c & 15) << 12) | ((c1 & 63) << 6) | (c2 & 63));
              i += 3;
          }
      }
      return string;
  }
}

export {
  Base64
}

二、用法

（1）引入方法

javascript">import { Base64 } from '../../utils/base.js'

（2）加密解密

javascript">var str = '加密内容'
var base = new Base64
var result = base.encode(str); // 加密
var result2 = base.decode(result); // 解密