// 字符串转换成byte[]
function stringToByte(str) {
  var bytes = new Array();
  var len, c;
  len = str.length;
  for (var i = 0; i < len; i++) {
    c = str.charCodeAt(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;
}

// byte[]转换成字符串
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 += String.fromCharCode(parseInt(store, 2));
      i += bytesLength - 1;
    } else {
      str += String.fromCharCode(_arr[i]);
    }
  }
  return str;
}

//十六进制字符串转字节数组，跟网上demo一样
function HexString2Bytes(str) {
  var pos = 0;
  var len = str.length;
  if (len % 2 != 0) {
    return null;
  }
  len /= 2;
  var arrBytes = new Array();
  for (var i = 0; i < len; i++) {
    var s = str.substr(pos, 2);
    var v = parseInt(s, 16);
    arrBytes.push(v);
    pos += 2;
  }
  return arrBytes;
}

//字节数组转十六进制字符串，对负值填坑
function Bytes2HexString(arrBytes) {
  var str = "";
  for (var i = 0; i < arrBytes.length; i++) {
    var tmp;
    var num = arrBytes[i];
    if (num < 0) {
      //此处填坑，当byte因为符合位导致数值为负时候，需要对数据进行处理
      tmp = (255 + num + 1).toString(16);
    } else {
      tmp = num.toString(16);
    }
    if (tmp.length == 1) {
      tmp = "0" + tmp;
    }
    str += tmp;
  }
  return str;
}