javascript 生成UUID

代码一： 

/*!
Math.uuid.js (v1.4)
 http://www.broofa.com
 mailto:robert@broofa.com
  
 Copyright (c) 2010 Robert Kieffer
 Dual licensed under the MIT and GPL licenses.
 */
  
 /*
  * Generate a random uuid.
  *
  * USAGE: Math.uuid(length, radix)
  *   length - the desired number of characters
  *   radix  - the number of allowable values for each character.
  *
  * EXAMPLES:
  *   // No arguments  - returns RFC4122, version 4 ID
  *   >>> Math.uuid()
  *   "92329D39-6F5C-4520-ABFC-AAB64544E172"
  *
  *   // One argument - returns ID of the specified length
  *   >>> Math.uuid(15)     // 15 character ID (default base=62)
  *   "VcydxgltxrVZSTV"
  *
  *   // Two arguments - returns ID of the specified length, and radix. (Radix must be <= 62)
  *   >>> Math.uuid(8, 2)  // 8 character ID (base=2)
  *   "01001010"
  *   >>> Math.uuid(8, 10) // 8 character ID (base=10)
  *   "47473046"
  *   >>> Math.uuid(8, 16) // 8 character ID (base=16)
  *   "098F4D35"
  */
 (function() {
   // Private array of chars to use
   var CHARS = ‘0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz‘.split(‘‘);
  
   Math.uuid = function (len, radix) {
     var chars = CHARS, uuid = [], i;
     radix = radix || chars.length;
  
     if (len) {
       // Compact form
       for (i = 0; i < len; i++) uuid[i] = chars[0 | Math.random()*radix];
     } else {
       // rfc4122, version 4 form
       var r;
  
       // rfc4122 requires these characters
       uuid[8] = uuid[13] = uuid[18] = uuid[23] = ‘-‘;
       uuid[14] = ‘4‘;
  
       // Fill in random data.  At i==19 set the high bits of clock sequence as
       // per rfc4122, sec. 4.1.5
       for (i = 0; i < 36; i++) {
         if (!uuid[i]) {
           r = 0 | Math.random()*16;
           uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
         }
       }
     }
  
     return uuid.join(‘‘);
   };
  
   // A more performant, but slightly bulkier, RFC4122v4 solution.  We boost performance
   // by minimizing calls to random()
   Math.uuidFast = function() {
     var chars = CHARS, uuid = new Array(36), rnd=0, r;
     for (var i = 0; i < 36; i++) {
       if (i==8 || i==13 ||  i==18 || i==23) {
         uuid[i] = ‘-‘;
       } else if (i==14) {
         uuid[i] = ‘4‘;
       } else {
         if (rnd <= 0x02) rnd = 0x2000000 + (Math.random()*0x1000000)|0;
         r = rnd & 0xf;
         rnd = rnd >> 4;
         uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
       }
     }
     return uuid.join(‘‘);
   };
  
   // A more compact, but less performant, RFC4122v4 solution:
   Math.uuidCompact = function() {
     return ‘xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx‘.replace(/[xy]/g, function(c) {
       var r = Math.random()*16|0, v = c == ‘x‘ ? r : (r&0x3|0x8);
       return v.toString(16);
     });
   };
 })(); 

调用方法：Math.uuid() 

代码二： 

//On creation of a UUID object, set it‘s initial value
 function UUID(){
     this.id = this.createUUID();
 }

 // When asked what this Object is, lie and return it‘s value
 UUID.prototype.valueOf = function(){ return this.id; };
 UUID.prototype.toString = function(){ return this.id; };

 //
 // INSTANCE SPECIFIC METHODS
 //
 UUID.prototype.createUUID = function(){
     //
     // Loose interpretation of the specification DCE 1.1: Remote Procedure Call
     // since JavaScript doesn‘t allow access to internal systems, the last 48 bits
     // of the node section is made up using a series of random numbers (6 octets long).
     // 
     var dg = new Date(1582, 10, 15, 0, 0, 0, 0);
     var dc = new Date();
     var t = dc.getTime() - dg.getTime();
     var tl = UUID.getIntegerBits(t,0,31);
     var tm = UUID.getIntegerBits(t,32,47);
     var thv = UUID.getIntegerBits(t,48,59) + ‘1‘; // version 1, security version is 2
     var csar = UUID.getIntegerBits(UUID.rand(4095),0,7);
     var csl = UUID.getIntegerBits(UUID.rand(4095),0,7);

     // since detection of anything about the machine/browser is far to buggy,
     // include some more random numbers here
     // if NIC or an IP can be obtained reliably, that should be put in
     // here instead.
     var n = UUID.getIntegerBits(UUID.rand(8191),0,7) +
             UUID.getIntegerBits(UUID.rand(8191),8,15) +
             UUID.getIntegerBits(UUID.rand(8191),0,7) +
             UUID.getIntegerBits(UUID.rand(8191),8,15) +
             UUID.getIntegerBits(UUID.rand(8191),0,15); // this last number is two octets long
     return tl + tm  + thv  + csar + csl + n;
 };

 //Pull out only certain bits from a very large integer, used to get the time
 //code information for the first part of a UUID. Will return zero‘s if there
 //aren‘t enough bits to shift where it needs to.
 UUID.getIntegerBits = function(val,start,end){
     var base16 = UUID.returnBase(val,16);
     var quadArray = new Array();
     var quadString = ‘‘;
     var i = 0;
     for(i=0;i<base16.length;i++){
         quadArray.push(base16.substring(i,i+1));   
     }
     for(i=Math.floor(start/4);i<=Math.floor(end/4);i++){
         if(!quadArray[i] || quadArray[i] == ‘‘) quadString += ‘0‘;
         else quadString += quadArray[i];
     }
     return quadString;
 };

 //Replaced from the original function to leverage the built in methods in
 //JavaScript. Thanks to Robert Kieffer for pointing this one out
 UUID.returnBase = function(number, base){
     return (number).toString(base).toUpperCase();
 };

 //pick a random number within a range of numbers
 //int b rand(int a); where 0 <= b <= a
 UUID.rand = function(max){
     return Math.floor(Math.random() * (max + 1));
 }; 

调用方法：UUID.prototype.createUUID()