Javascript Base64编码与解码
分类: JavaScript 2015-02-04 14:25 212人阅读 评论(0) 收藏 举报
转自:http://blog.csdn.net/yanzhibo/article/details/20079943
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- <html>
- <head>
- <META HTTP-EQUIV="MSThemeCompatible" CONTENT="Yes">
- <meta http-equiv="Content-Type" content="text/html; charset=unicode">
- <script language="JavaScript" type="text/javascript" src="../var.js"></script>
- <title>Base64 Encode and Decode</title>
- <style>
- </style>
- <script type="text/javascript" language="javascript">
- var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
- var base64DecodeChars = new Array(
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
- -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
- 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
- -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
- 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
- function base64encode(str) {
- var out, i, len;
- var c1, c2, c3;
- len = str.length;
- i = 0;
- out = "";
- while(i < len) {
- c1 = str.charCodeAt(i++) & 0xff;
- if(i == len)
- {
- out += base64EncodeChars.charAt(c1 >> 2);
- out += base64EncodeChars.charAt((c1 & 0x3) << 4);
- out += "==";
- break;
- }
- c2 = str.charCodeAt(i++);
- if(i == len)
- {
- out += base64EncodeChars.charAt(c1 >> 2);
- out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
- out += base64EncodeChars.charAt((c2 & 0xF) << 2);
- out += "=";
- break;
- }
- c3 = str.charCodeAt(i++);
- out += base64EncodeChars.charAt(c1 >> 2);
- out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
- out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6));
- out += base64EncodeChars.charAt(c3 & 0x3F);
- }
- return out;
- }
- function base64decode(str) {
- var c1, c2, c3, c4;
- var i, len, out;
- len = str.length;
- i = 0;
- out = "";
- while(i < len) {
- /* c1 */
- do {
- c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
- } while(i < len && c1 == -1);
- if(c1 == -1)
- break;
- /* c2 */
- do {
- c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
- } while(i < len && c2 == -1);
- if(c2 == -1)
- break;
- out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
- /* c3 */
- do {
- c3 = str.charCodeAt(i++) & 0xff;
- if(c3 == 61)
- return out;
- c3 = base64DecodeChars[c3];
- } while(i < len && c3 == -1);
- if(c3 == -1)
- break;
- out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
- /* c4 */
- do {
- c4 = str.charCodeAt(i++) & 0xff;
- if(c4 == 61)
- return out;
- c4 = base64DecodeChars[c4];
- } while(i < len && c4 == -1);
- if(c4 == -1)
- break;
- out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
- }
- return out;
- }
- function utf16to8(str) {
- var out, i, len, c;
- out = "";
- len = str.length;
- for(i = 0; i < len; i++) {
- c = str.charCodeAt(i);
- if ((c >= 0x0001) && (c <= 0x007F)) {
- out += str.charAt(i);
- } else if (c > 0x07FF) {
- out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
- out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
- out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
- } else {
- out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
- out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
- }
- }
- return out;
- }
- function utf8to16(str) {
- var out, i, len, c;
- var char2, char3;
- out = "";
- len = str.length;
- i = 0;
- while(i < len) {
- c = str.charCodeAt(i++);
- switch(c >> 4)
- {
- case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
- // 0xxxxxxx
- out += str.charAt(i-1);
- break;
- case 12: case 13:
- // 110x xxxx 10xx xxxx
- char2 = str.charCodeAt(i++);
- out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
- break;
- case 14:
- // 1110 xxxx 10xx xxxx 10xx xxxx
- char2 = str.charCodeAt(i++);
- char3 = str.charCodeAt(i++);
- out += String.fromCharCode(((c & 0x0F) << 12) |
- ((char2 & 0x3F) << 6) |
- ((char3 & 0x3F) << 0));
- break;
- }
- }
- return out;
- }
- function CharToHex(str) {
- var out, i, len, c, h;
- out = "";
- len = str.length;
- i = 0;
- while(i < len)
- {
- c = str.charCodeAt(i++);
- h = c.toString(16);
- if(h.length < 2)
- h = "0" + h;
- out += "\\x" + h + " ";
- if(i > 0 && i % 8 == 0)
- out += "\r\n";
- }
- return out;
- }
- function doEncode() {
- var src = document.getElementById(‘src‘).value;
- document.getElementById(‘dest‘).value = base64encode(utf16to8(src));
- }
- function doDecode() {
- var src = document.getElementById(‘src‘).value;
- var opts = document.getElementById(‘opt‘);
- if(opts.checked)
- {
- document.getElementById(‘dest‘).value = CharToHex(base64decode(src));
- }
- else
- {
- document.getElementById(‘dest‘).value = utf8to16(base64decode(src));
- }
- }
- </script>
- </head>
- <BODY bgcolor="#EAF0F8" topmargin="10" leftmargin="10" rightmargin="10" bottommargin="10">
- <div id="contain" style="font-family: Tahoma, Arial; font-size:11pt">
- <div id="mainbg">
- <div style="color: #000080; margin-bottom: 10"><b>Base64 Encode / Decode</b></div>
- <div>
- <textarea id="src" rows=11 cols=60 value="" name="src"></textarea>
- <div style="margin: 10 0 10 0">
- <input onclick="doEncode();" type=button value="Encode" name="encode">
- <input onclick="doDecode();" type=button value="Decode" name="decode">
- <input type="checkbox" value="hex" name="opt" id="opt">Hex
- </div>
- <textarea id="dest" rows=11 cols=60 value="" name="dest"></textarea>
- </div>
- </div>
- </div>
- </BODY>
- </html>
时间: 2024-08-10 00:05:05