contentreader.js

用java+Ajax做的图书商城

var contentReader=new Object();

contentReader=function(url,onload,onerror){
  this.req=null;
  this.onload=onload;
  this.onerror=(onerror) ? onerror : this.defaultError;
  this.loadXMLDoc(url);
}

contentReader.prototype.loadXMLDoc=function(url){
  if (window.XMLHttpRequest){
    this.req=new XMLHttpRequest();
  } else if (window.ActiveXObject){
    this.req=new ActiveXObject("Microsoft.XMLHTTP");
  }
  if (this.req){
    try{
      var loader=this;
      this.req.onreadystatechange=function(){
       contentReader.onReadyState.call(loader);
      }
      this.req.open('GET',url,true);
      this.req.send(null);
    }catch (err){
      this.onerror.call(this);
    }
  }
}

contentReader.onReadyState=function(){
  var req=this.req;
  var ready=req.readyState;
  if (ready==4){
      var httpStatus=req.status;
    if (httpStatus==200 || httpStatus==0){
      this.onload.call(this);
    }else{
      this.onerror.call(this);
    }
  }
}

contentReader.prototype.defaultError=function(){
  alert("error fetching data!"
    +" readyState:"+this.req.readyState
    +" status: "+this.req.status
    +" headers: "+this.req.getAllResponseHeaders());
}