js byte[] 和string 相互转换 UTF-8
//字符串转字节序列
function stringToByte(str) {
var bytes = new Array();
var len, c;
len = str.length;
for(var i = 0; i < len; i++) {
c = (i);
if(c >= 0x010000 && c <= 0x10FFFF) {
bytes.push(((c >> 18) & 0x07) | 0xF0);
bytes.push(((c >> 12) & 0x3F) | 0x80);
bytes.push(((c >> 6) & 0x3F) | 0x80);
bytes.push((c & 0x3F) | 0x80);
} else if(c >= 0x000800 && c <= 0x00FFFF) {
bytes.push(((c >> 12) & 0x0F) | 0xE0);
bytes.push(((c >> 6) & 0x3F) | 0x80);
bytes.push((c & 0x3F) | 0x80);
} else if(c >= 0x000080 && c <= 0x0007FF) {
bytes.push(((c >> 6) & 0x1F) | 0xC0);
bytes.push((c & 0x3F) | 0x80);
} else {
bytes.push(c & 0xFF);
}
}
return bytes;
}
//字节序列转ASCII码
//[0x24, 0x26, 0x28, 0x2A] ==> "$&C*"
function byteToString(arr) {
if(typeof arr === 'string') {
return arr;
}
var str = '',
_arr = arr;
for(var i = 0; i < _arr.length; i++) {
var one = _arr[i].toString(2),
v = one.match(/^1+?(?=0)/);
if(v && one.length == 8) {
var bytesLength = v[0].length;
var store = _arr[i].toString(2).slice(7 - bytesLength);
for(var st = 1; st < bytesLength; st++) {
store += _arr[st + i].toString(2).slice(2);
}
str += (parseInt(store, 2));
i += bytesLength - 1;
} else {
str += (_arr[i]);
}
}
return str;
}