This article describes the method of JS implementing Base64 encoding of utf-8 in Chinese strings. Share it for your reference, as follows:
String to be encoded: "select username from user"
Use JAVA for encoding, Java program:
String sql = "select username from user";String encodeStr = new String(Base64.encode(sql.getBytes("UTF-8"))); // Encoding System.out.println(encodeStr);get:
c2VsZWN0IOeUqOaIt+WQjSBmcm9tIOeUqOaItw==
Decode in Java:
sql = new String(Base64.decode(sql.getBytes()), "UTF-8");
Why use getBytes("UTF-8") in Java code? Because the default encodings in Windows and Linux environments are different, to make your program get the same encoding on different platforms, you must specify the encoding.
Although the encoding of Html and JS are both utf-8, the Chinese encoding obtained by JS from the page is utf-16, so directly encoded Chinese with Base64 will get the wrong result, so we need to first transfer from utf-16 to utf-8 and then encode it.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title></title><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><style type="text/css"><!--body{ margin:0px; padding:0px;}body,td{ font-size:9pt;}--></style><script type="text/JavaScript"><!--var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";//Base64 encoding of Ansi-encoded string function encode64(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;}//Convert Base64 encoded string to Ansi-encoded string function decode64(input) {var output = "";var chr1, chr2, chr3 = "";var enc1, enc2, enc3, enc4 = "";var i = 0;if (input.length % 4 != 0) {return "";}var base64test = /[^A-Za-z0-9/+///=]/g;if (base64test.exec(input)) {return "";}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 += String.fromCharCode(chr2);}if (enc4 != 64) {output += String.fromCharCode(chr3);}chr1 = chr2 = chr3 = "";enc1 = enc2 = enc3 = enc4 = "";} while (i < input.length);return output;}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: // 0xxxxxx 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 char2 = str.charCodeAt(i++); char3 = str.charCodeAt(i++); out += String.fromCharCode(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0)); break; } } return out;}// Test code start var de = encode64(utf16to8("select username from user"));document.writeln(de+"<br>");var ee = utf8to16(decode64(de))document.writeln(ee);// Test code end //--></script></head><body></body></html>The above codes are all obtained from the Internet and get the correct results after being pieced together. Thank you for your seniors.
PS: Here are a few more base64 encoding and decoding online tools, I believe that they will be used in future development:
BASE64 encoding and decoding tools:
http://tools.VeVB.COM/transcoding/base64
Online picture conversion BASE64 tool:
http://tools.VeVB.COM/transcoding/img2base64
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I hope this article will be helpful to everyone's JavaScript programming.