分享一下Java和微信小程式的 BASE64 加密。
Java：
package com.core.util;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* Base64編碼工具類
*/
public class Base64 {
private static final char [] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" .toCharArray();
public static String encode(byte [] data) {
int start = 0 ;
int len = data.length;
StringBuffer buf = new StringBuffer(data.length * 3 / 2 );
int end = len - 3 ;
int i = start;
int n = 0 ;
while (i <= end) {
int d = (((( int ) data[i]) & 0x0ff ) << 16 ) | (((( int ) data[i + 1 ]) & 0x0ff ) << 8 ) | ((( int ) data[i + 2 ]) & 0x0ff );
buf.append(legalChars[(d >> 18 ) & 63 ]);
buf.append(legalChars[(d >> 12 ) & 63 ]);
buf.append(legalChars[(d >> 6 ) & 63 ]);
buf.append(legalChars[d & 63 ]);
i += 3 ;
if (n++ >= 14 ) {
n = 0 ;
buf.append( " " );
}
}
if (i == start + len - 2 ) {
int d = (((( int ) data[i]) & 0x0ff ) << 16 ) | (((( int ) data[i + 1 ]) & 255 ) << 8 );
buf.append(legalChars[(d >> 18 ) & 63 ]);
buf.append(legalChars[(d >> 12 ) & 63 ]);
buf.append(legalChars[(d >> 6 ) & 63 ]);
buf.append( "=" );
} else if (i == start + len - 1 ) {
int d = ((( int ) data[i]) & 0x0ff ) << 16 ;
buf.append(legalChars[(d >> 18 ) & 63 ]);
buf.append(legalChars[(d >> 12 ) & 63 ]);
buf.append( "==" );
}
return buf.toString();
}
private static int decode( char c) {
if (c >= 'A' && c <= 'Z' )
return (( int ) c) - 65 ;
else if (c >= 'a' && c <= 'z' )
return (( int ) c) - 97 + 26 ;
else if (c >= '0' && c <= '9' )
return (( int ) c) - 48 + 26 + 26 ;
else
switch (c) {
case '+' :
return 62 ;
case '/' :
return 63 ;
case '=' :
return 0 ;
default :
throw new RuntimeException( "unexpected code: " + c);
}
}
public static byte [] decode(String s) {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
decode(s, bos);
} catch (IOException e) {
throw new RuntimeException();
}
byte [] decodedBytes = bos.toByteArray();
try {
bos.close();
bos = null ;
} catch (IOException ex) {
System.err.println( "Error while decoding BASE64: " + ex.toString());
}
return decodedBytes;
}
private static void decode(String s, OutputStream os) throws IOException {
int i = 0 ;
int len = s.length();
while ( true ) {
while (i < len && s.charAt(i) <= ' ' )
i++;
if (i == len)
break ;
int tri = (decode(s.charAt(i)) << 18 ) + (decode(s.charAt(i + 1 )) << 12 ) + (decode(s.charAt(i + 2 )) << 6 ) + (decode(s.charAt(i + 3 )));
os.write((tri >> 16 ) & 255 );
if (s.charAt(i + 2 ) == '=' )
break ;
os.write((tri >> 8 ) & 255 );
if (s.charAt(i + 3 ) == '=' )
break ;
os.write(tri & 255 );
i += 4 ;
}
}
}
微信小程式 js
(function (global) {
'use strict';
var global = global || {};
// existing version for noConflict()
var _Base64 = global.Base64;
var version = "2.1.9";
// if node.js, we use Buffer
var buffer;
// constants
var b64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var b64tab = function (bin) {
var t = {};
for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
return t;
}(b64chars);
var fromCharCode = String.fromCharCode;
// encoder stuff
var cb_utob = function (c) {
if (c.length < 2) {
var cc = c.charCodeAt(0);
return cc < 0x80 ? c :
cc < 0x800 ? (fromCharCode(0xc0 | (cc >>> 6)) +
fromCharCode(0x80 | (cc & 0x3f))) :
(fromCharCode(0xe0 | ((cc >>> 12) & 0x0f)) +
fromCharCode(0x80 | ((cc >>> 6) & 0x3f)) +
fromCharCode(0x80 | (cc & 0x3f)));
} else {
var cc = 0x10000 +
(c.charCodeAt(0) - 0xD800) * 0x400 +
(c.charCodeAt(1) - 0xDC00);
return (fromCharCode(0xf0 | ((cc >>> 18) & 0x07)) +
fromCharCode(0x80 | ((cc >>> 12) & 0x3f)) +
fromCharCode(0x80 | ((cc >>> 6) & 0x3f)) +
fromCharCode(0x80 | (cc & 0x3f)));
}
};
var re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
var utob = function (u) {
return u.replace(re_utob, cb_utob);
};
var cb_encode = function (ccc) {
var padlen = [0, 2, 1][ccc.length % 3],
ord = ccc.charCodeAt(0) << 16 |
((ccc.length > 1 ? ccc.charCodeAt(1) : 0) << 8) |
((ccc.length > 2 ? ccc.charCodeAt(2) : 0)),
chars = [
b64chars.charAt(ord >>> 18),
b64chars.charAt((ord >>> 12) & 63),
padlen >= 2 ? '=' : b64chars.charAt((ord >>> 6) & 63),
padlen >= 1 ? '=' : b64chars.charAt(ord & 63)
];
return chars.join('');
};
var btoa = global.btoa ? function (b) {
return global.btoa(b);
} : function (b) {
return b.replace(/[\s\S]{1,3}/g, cb_encode);
};
var _encode = buffer ? function (u) {
return (u.constructor === buffer.constructor ? u : new buffer(u))
.toString('base64')
} :
function (u) { return btoa(utob(u)) };
var encode = function (u, urisafe) {
return !urisafe ?
_encode(String(u)) :
_encode(String(u)).replace(/[+\/]/g, function (m0) {
return m0 == '+' ? '-' : '_';
}).replace(/=/g, '');
};
var encodeURI = function (u) { return encode(u, true) };
// decoder stuff
var re_btou = new RegExp([
'[\xC0-\xDF][\x80-\xBF]',
'[\xE0-\xEF][\x80-\xBF]{2}',
'[\xF0-\xF7][\x80-\xBF]{3}'
].join('|'), 'g');
var cb_btou = function (cccc) {
switch (cccc.length) {
case 4:
var cp = ((0x07 & cccc.charCodeAt(0)) << 18) |
((0x3f & cccc.charCodeAt(1)) << 12) |
((0x3f & cccc.charCodeAt(2)) << 6) |
(0x3f & cccc.charCodeAt(3)),
offset = cp - 0x10000;
return (fromCharCode((offset >>> 10) + 0xD800) +
fromCharCode((offset & 0x3FF) + 0xDC00));
case 3:
return fromCharCode(
((0x0f & cccc.charCodeAt(0)) << 12) |
((0x3f & cccc.charCodeAt(1)) << 6) |
(0x3f & cccc.charCodeAt(2))
);
default:
return fromCharCode(
((0x1f & cccc.charCodeAt(0)) << 6) |
(0x3f & cccc.charCodeAt(1))
);
}
};
var btou = function (b) {
return b.replace(re_btou, cb_btou);
};
var cb_decode = function (cccc) {
var len = cccc.length,
padlen = len % 4,
n = (len > 0 ? b64tab[cccc.charAt(0)] << 18 : 0) |
(len > 1 ? b64tab[cccc.charAt(1)] << 12 : 0) |
(len > 2 ? b64tab[cccc.charAt(2)] << 6 : 0) |
(len > 3 ? b64tab[cccc.charAt(3)] : 0),
chars = [
fromCharCode(n >>> 16),
fromCharCode((n >>> 8) & 0xff),
fromCharCode(n & 0xff)
];
chars.length -= [0, 0, 2, 1][padlen];
return chars.join('');
};
var atob = global.atob ? function (a) {
return global.atob(a);
} : function (a) {
return a.replace(/[\s\S]{1,4}/g, cb_decode);
};
var _decode = buffer ? function (a) {
return (a.constructor === buffer.constructor ?
a : new buffer(a, 'base64')).toString();
} :
function (a) { return btou(atob(a)) };
var decode = function (a) {
return _decode(
String(a).replace(/[-_]/g, function (m0) { return m0 == '-' ? '+' : '/' })
.replace(/[^A-Za-z0-9\+\/]/g, '')
);
};
var noConflict = function () {
var Base64 = global.Base64;
global.Base64 = _Base64;
return Base64;
};
// export Base64
global.Base64 = {
VERSION: version,
atob: atob,
btoa: btoa,
fromBase64: decode,
toBase64: encode,
utob: utob,
encode: encode,
encodeURI: encodeURI,
btou: btou,
decode: decode,
noConflict: noConflict
};
// if ES5 is available, make Base64.extendString() available
if (typeof Object.defineProperty === 'function') {
var noEnum = function (v) {
return { value: v, enumerable: false, writable: true, configurable: true };
};
global.Base64.extendString = function () {
Object.defineProperty(
String.prototype, 'fromBase64', noEnum(function () {
return decode(this)
}));
Object.defineProperty(
String.prototype, 'toBase64', noEnum(function (urisafe) {
return encode(this, urisafe)
}));
Object.defineProperty(
String.prototype, 'toBase64URI', noEnum(function () {
return encode(this, true)
}));
};
}
module.exports = global.Base64;
})(this);
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