code: function bytesToString(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;
  }
docs: byteArray数据格式转字符串