JavaScript AJAX类

  function AjaxTool(){}; 
  3    AjaxTool.prototype=    
  4    {                           
  5       ajaxPool:[],  //XMLHttpRequest 连接池
  6       userName:'', //用户访问帐号
  7       userPwd:'',  //用户访问密码
  8       requestHeaders:{'Count':0,'Items':[]},  //存放请求头
  9       getInstance:function()
 10       {
 11          for(var i=0;i<this.ajaxPool.length;i++)
 12          {
 13             if(this.ajaxPool[i].readyState==0 || this.ajaxPool[i].readyState==4)
 14                return this.ajaxPool[i];
 15          }
 16          this.ajaxPool[length]=this.createXmlHttp();
 17          return this.ajaxPool[length];
 18       }, //end of getInstance();
 19       createXmlHttp:function()
 20       {
 21          if(window.XMLHttpRequest)
 22           {
 23              return new XMLHttpRequest();
 24           }
 25          else
 26          {
 27             var xmlHttps=['Microsoft.XMLHTTP','MSXML2.XMLHTTP','MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0'];
 28             for(var i=0;i<xmlHttps.length;i++)
 29             {
 30                try
 31                {
 32                   return new ActiveXObject(xmlHttps[i]);
 33                }
 34                catch ($e)
 35                {
 36                   continue;
 37                }
 38             }
 39          }
 40       }, //end of createXmlHttp()
 41       setLoginInfo:function(username,password)
 42       {
 43          if(typeof username!=='string' || username.length<=0)
 44            throw new Error('UserName must be a string');
 45          if(typeof password!=='string' || password.length<=0)
 46            throw new Error('Password must be a string');
 47          this.userName=username;
 48          this.userPwd=password;
 49       }, //end of setLoginInfo
 50       setRequestHeader:function (name, value)
 51       {        
 52         if ('string' !== typeof(name) || name.length<=0)
 53         {
 54             throw new Error('RequestHeader\'s name must be a string！');
 55         }
 56         if ('string' !== typeof(value)|| value.length<=0)
 57         {
 58             throw new Error('RequestHeader\'s value must be a string！');
 59         }        
 60         this.requestHeaders.Count = this.requestHeaders.Count + 1;
 61         this.requestHeaders.Items[name] = value;
 62       }, //end of setRequestHeader()
 63       handleCallBack:function(xmlHtp,callBack,args)
 64       {
 66          return function()
 67          {
 68             if(xmlHtp.readyState==4)
 69             {
 70                 if(xmlHtp.status==200)
 71                 {
 72                    if(args.length>5)
 73                    {
 74                        var extendArgs=[];
 75                         for(var i=5;i<args.length;i++)
 76                         {
 77                             extendArgs.push(args[i]);
 78                             callBack(xmlHtp,extendArgs);
 79                         }
 80                     }
 81                     else
 82                     {
 83                        callBack(xmlHtp);
 84                     }
 85                 }
 86             }
 87          }
 88       }, //end of handlerCallBack
 89       sendRequest:function(method,url,data,callBack,disableCache)
 90       {
 91          if (typeof(method)!=='string')
 92          {
 93             throw new Error('method must be a string type');
 94          }
 95          if (typeof(url)!=='string')
 96          {
 97             throw new Error('url must be a string type');
 98          }
 99          method = method.toLowerCase();
100          if ('get' !== method && 'post' !== method)
101          {
102             method = 'get';
103          }
104          var async = ('function' === typeof(callBack));  
105          try
106          {
107             var xmlHtp=this.getInstance();
108             if(async)
109             {
110                 xmlHtp.onreadystatechange=this.handleCallBack(xmlHtp,callBack,arguments);
111                 if(method=='get' && typeof(data)=='string' && data.length>0)
112                 {                    
113                     xmlHtp.open(method,url+(url.indexOf('?')!=-1?('&'+data):('?'+data)),async,this.userName,this.userPwd);
114                 }
115                 else
116                 {                    
117                     xmlHtp.open(method,url,async,this.userName,this.userPwd);
118                 }
119                 if (true === disableCache)
120                 {                    
121                    this.setRequestHeader('If-Modified-Since', '0');
122                 }
123                 if (this.requestHeaders.Count > 0)
124                 {
125                   for (var key in this.requestHeaders.Items)
126                   {
127                       xmlHtp.setRequestHeader(key, this.requestHeaders.Items[key]);
128                   }
129                 }
130                 if ('get' === method)
131                 {
132                     xmlHtp.send(null);
133                 }
134                 else
135                 {
136                     xmlHtp.send(data);
137                 }                
138             }
139             else  
140             {
141                 return xmlHtp;
142             }
143          }
144          catch ($e)
145          {
146              throw $e;
147          }
148       } //end of sendRequest([args]);
149    };