XMLHttpRequest状态为4，但responseText为空

XMLHttpRequest status 4 but responseText is empty

本文关键字：responseText 为空 状态 XMLHttpRequest      更新时间：2023-09-26

我想写一个谷歌广告像javaScript插件。我不能使用jQuery ajax，因为它应该是工作良好的所有网站。这是我的JavaScript代码。

var ajaxRequest;  // The variable that makes Ajax possible!
try{
    // Opera 8.0+, Firefox, Safari
    ajaxRequest = new XMLHttpRequest();
} catch (e){
    // Internet Explorer Browsers
    try{
        ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
        try{
            ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e){
            // Something went wrong
            alert("Your browser broke!");
            return false;
        }
    }
}
// Create a function that will receive data sent from the server
ajaxRequest.onreadystatechange = function(){
    if(ajaxRequest.readyState == 4){
        alert( ajaxRequest.responseText);
        console.log('xhr',ajaxRequest)
    } else {
        //alert(ajaxRequest.readyState);
        //alert(ajaxRequest.responseText);
    }
}
    var project_path = "http://www.domainname.com/"; //for stackoverflow, using right path in live code.
var req_url = project_path + "ads/verifypublisher/";
ajaxRequest.open("GET", req_url, true);
ajaxRequest.send(null);

我的PHP文件是这样的，

echo("<b>hi:</b> ");
exit();

是的，这是我所有的。responseText仍然是空的。我错过了什么?

alert(req_url)应该显示错误的url "http://www.domainname.comads/verifypublisher/"

在对响应执行任何操作之前，最好确保状态码为200。这样您就可以更早地发现问题。

在我的测试中，它在大多数浏览器中工作

var responseText=function(e,doing){
                     if (e.readyState== 4) {
                           if(doing)doing(e);
                           return(e.responseText);              
                     };
                     if (e.readyState == 200) { 
                           if(doing)doing(e);               
                           return(e.responseText);
                     };
                     return false;                   
};
function  loadXMLPostDocf(url,method,posData,uploadProgress,uploadComplete,uploadFailed,uploadCanceled,statechange,CallBackOnSend) {
   var arrSignatures = ["MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0","MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP","Microsoft.XMLHTTP"];
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest && checkVersion()) {
    pos = new XMLHttpRequest(); 
    pos.open(method, url, true);
    //pos.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    if(statechange!=''){pos.onreadystatechange = statechange;};
    try{
      if(uploadProgress!='')if(pos.upload){
          pos.upload.addEventListener("progress", uploadProgress, true);
      }else{
          pos.addEventListener("progress", uploadProgress, true);
      }
      if(uploadComplete!='')pos.addEventListener("load", uploadComplete, false);
      if(uploadFailed!='')pos.addEventListener("error", uploadFailed, false);
      if(uploadCanceled!='')pos.addEventListener("abort", uploadCanceled, false);
    }catch(e){
    }
    pos.send(posData);
    if(CallBackOnSend)CallBackOnSend(pos);
    //console.log(pos.abort());
// branch for IE/Windows ActiveX version
} else if (window.ActiveXObject) {  
         for (var i=0; i < arrSignatures.length; i++) {
                    try {
                        pos = new ActiveXObject(arrSignatures[i]);
                    } catch (oError) {
                        //ignore
                    };
          };
    if (pos) {
        pos.open(method, url, false);
        //pos.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        if(!statechange){pos.onreadystatechange = statechange;};
        if(!uploadComplete){pos.onreadystatechange = uploadComplete;};
       // if(uploadProgress!='')pos.upload.addEventListener("progress", uploadProgress, true);
        //if(uploadComplete!='')pos.addEventListener("load", uploadComplete, false);
        //if(uploadFailed!='')pos.addEventListener("error", uploadFailed, false);
        //if(uploadCanceled!='')pos.addEventListener("abort", uploadCanceled, false);
        pos.send(posData);
        if(CallBackOnSend)CallBackOnSend(pos);
    };   
 };
 return(pos);
};
示例:

 var complete=function(e){
    var Body=responseText(e.target);
    console.log(Body);
};
var uploadProgress=function(evt){
};
var uploadComplete=function(evt){
    if(evt.target.status==200 || evt.target.status==304){
      var Body=responseText(evt.target);
      console.log(Body);
    }else{
        return false;
    };
};
var uploadFailed=function(evt){
};
var uploadCanceled=function(evt){
};
var CallBackOnSend=function(evt){
};
loadXMLPostDocf("http://domain.com/index.php","GET",null,uploadProgress,uploadComplete,uploadFailed,uploadCanceled,complete,CallBackOnSend);

我的问题类似于这是通过检查我的html代码解决。我有一个onclick处理程序在我的表单提交按钮到一个方法。像这样:onclick="sendFalconRequestWithHeaders()"。这个方法反过来调用ajax，就像您的方法一样，并做我想做的事情。但不像预期的那样，我的浏览器什么也没有返回。

经过别人的努力，我在这个处理程序中返回了false，并解决了。让我提一下，在到达这篇文章之前，我花了整整3天的周末和半天的时间在办公室写代码实现CORS filters, jetty config和其他jersey and embedded jetty相关的东西-只是为了解决这个问题。我所有的理解都围绕着cross domain ajax requests和标准的东西。javascript中简单的错误会让你变傻，这真是太可笑了。

现在我必须清理我的代码干净地提交git补丁。多亏了那个人

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