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December 13, 2014 15:03
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base64的js实现
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/** | |
* | |
* Base64 encode / decode | |
* originUrl: http://tuhaitao.iteye.com/blog/653244 | |
*/ | |
function Base64() { | |
// private property | |
_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; | |
// public method for encoding | |
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; | |
} | |
// public method for decoding | |
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; | |
} | |
// 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; | |
} | |
} |
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<html> | |
<head> | |
<script src="lib/base64.js" type="text/javascript"></script> | |
<script type="text/javascript"> | |
var b = new Base64(); | |
var str = b.encode("admin:admin"); | |
alert("base64 encode:" + str); | |
str = b.decode(str); | |
alert("base64 decode:" + str); | |
</script> | |
</head> | |
<body> | |
</body> | |
</html> |
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