当前位置: 首页 > 图文教程 > 网络编程 > Javascript > base64编码/解码

Javascript
javascript实现的动态添加表单元素input,button等(appendChild)
javascript动态添加单元格的脚本代码
[原创]仿google adsense颜色选择器代码,从中易广告联盟程序提取
asp javascript 实现关闭窗口时保存数据的办法
javascript 下拉框显示当前日期
惊云JS随机排序程序随机显示信息-每次新闻显示顺序都不一样
javascript下有关dom以及xml节点访问兼容问题
js 复制功能 支持 for IE/FireFox/mozilla/ns
css图片自适应大小
比较简单的一个符合web标准的JS调用flash方法
javascript数组组合成字符串的脚本
XRegExp 0.2: Now With Named Capture
jQuery 研究心得 取得属性的值
防止网站内容被拷贝的一些方法与优缺点好处与坏处分析
Prototype1.6 JS 官方下载地址
jquery 指南/入门基础
jquery api参考 visualjquery 中国线路 速度快
js控制fieldset高度的代码
document.documentElement && document.documentElement.scrollTop
js同时按下两个方向键

Javascript 中的 base64编码/解码


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-08-10   浏览: 451 ::
收藏到网摘: n/a

编者:解决了对中文的不支持问题.
先用escape()对中文进行编码.然后再进行base64编码.
解码时,再加入unescape()对中文进行解码.

<html>
   <head>
      <title>base64 Encoding/Decoding</title>
   </head>

   <script type="text/javascript"><!--

   var keyStr = "ABCDEFGHIJKLMNOP" +
                "QRSTUVWXYZabcdef" +
                "ghijklmnopqrstuv" +
                "wxyz0123456789+/" +
                "=";

   function encode64(input) {
      input = escape(input);
      var output = "";
      var chr1, chr2, chr3 = "";
      var enc1, enc2, enc3, enc4 = "";
      var i = 0;

      do {
         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);
         chr1 = chr2 = chr3 = "";
         enc1 = enc2 = enc3 = enc4 = "";
      } while (i < input.length);

      return output;
   }

   function decode64(input) {
      var output = "";
      var chr1, chr2, chr3 = "";
      var enc1, enc2, enc3, enc4 = "";
      var i = 0;

      // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
      var base64test = /[^A-Za-z0-9\+\/\=]/g;
      if (base64test.exec(input)) {
         alert("There were invalid base64 characters in the input text.\n" +
               "Valid base64 characters are A-Z, a-z, 0-9, '+', '/', and '='\n" +
               "Expect errors in decoding.");
      }
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

      do {
         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);
         }

         chr1 = chr2 = chr3 = "";
         enc1 = enc2 = enc3 = enc4 = "";

      } while (i < input.length);

      return unescape(output);
   }

   //--></script>

   <body>

      <form name="base64Form">

         Type in the message you want to encode in base64, or paste<br>
         base64 encoded text into the text field, select Encode or Decode, <br>
         and click the button!<br>

         <textarea name="theText" cols="40" rows="6"></textarea><br>

         <input type="button" name="encode" value="Encode to base64"
            onClick="document.base64Form.theText.value=encode64(document.base64Form.theText.value);">
         <input type="button" name="decode" value="Decode from base64"
            onClick="document.base64Form.theText.value=decode64(document.base64Form.theText.value);">

      </form>

   </body>
</html>


'