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>
