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;
 
 
		}
 
 
		 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;
		}
 

轉載地址: https://blog.csdn.net/u013022210/article/details/55101558/