var NumberUtil={

	//byte数组转换为int整数

	bytesToInt2:function(bytes, off) {

		var b3 = bytes[off] & 0xFF;

		var b2 = bytes[off + 1] & 0xFF;

		var b1 = bytes[off + 2] & 0xFF;

		var b0 = bytes[off + 3] & 0xFF;

		return (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;

	},

	//byte数组转换为无符号short整数

	byte2ToUnsignedShort:function(bytes, off) {

		var high = bytes[off + 1];

		var low = bytes[off];

		return (high << 8 & 0xFF00) | (low & 0xFF);

	},

	//byte数组转字符串

	byteToString:function(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;

	},

	//int整数转换为4字节的byte数组

	intToByte4:function(i) {

		var targets =[];

		targets[0] = (i & 0xFF);

		targets[1] = (i >> 8 & 0xFF);

		targets[2] = (i >> 16 & 0xFF);

		targets[3] = (i >> 24 & 0xFF);

		return targets;

	},

	//无符号short转换为2字节的byte数组

	unsignedShortToByte2:function(s){

		var targets = [];

		targets[1] = (s >> 8 & 0xFF);

		targets[0] = (s & 0xFF);

		return targets;

	},

	//字符串转byte数组

	stringToByte:function(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;

	},

	//有符int转无符int

	int2uint:function(i) {

	    if (i >= 0)

	        return i;

	    else

	        4294967296 + i;

	},

	//无符int转有符int

	uint2int:function(i) {

	    if (i <= 2147483647)

	        return i;

	    else

	        return i - 4294967296

	},

	//有符char转无符char

	char2uchar:function(i) {

	    if (i >= 0)

	        return i;

	    else

	        65535 + i;

	},

	//无符char转有符char

	uchar2char:function(i) {

	    if (i <= 32767)

	        return i;

	    else

	        return i - 65535

	},

	//有符byte转无符byte

	bytes2ubytes:function(i) {

	    if (i >= 0)

	        return i;

	    else

	        255 + i;

	},

	//无符byte转有符byte

	ubytes2bytes:function(i) {

	    if (i <= 127)

	        return i;

	    else

	        return i - 255

	}

}