问题很简单：当我提交表单时我必须下载文件，当提交表单时，它是一个ajax调用，它允许我使用从表单，服务器端获取的数据构建一个文件，然后发送它作为警报的链接。事实是我的老板希望直接下载文件，而不是通过警报中的链接。所以我必须通过龙卷风（网络）确保文件在服务器端可用：
self.set_header('Content-Type', 'application/octet-stream')
self.set_header('Content-Disposition', 'attachment; filename=clients_counter.zip')
with open("static/clients_counter.zip", 'r') as f:
while True:
data = f.read()
if not data:
break
self.write(data)
self.finish()
服务器端代码似乎工作正常，但客户端（extjs4.1）真的是一场噩梦。这就是我的ajax调用现在的样子，它不起作用：
Ext.Ajax.request({
method : "GET",
url : 'http://whatever.com/count?client='+client+'&start='+start+'&end='+end,
timeout : 30000,
success :
function (response) {
//Ext.Msg.alert(response.responseText);
desktop.getWindow('count-win').doClose();
return response;
}//handler,
failure :
function(response) {
alert("Wrong request");
}});
答案 0 :(得分：9)
在阅读Ext JS论坛的各种来源和stackoverflow之后，下面是我选择的方法（使用Ext JS 4.2.1版）：
downloadFile: function(config){
config = config || {};
var url = config.url,
method = config.method || 'POST',// Either GET or POST. Default is POST.
params = config.params || {};
// Create form panel. It contains a basic form that we need for the file download.
var form = Ext.create('Ext.form.Panel', {
standardSubmit: true,
url: url,
method: method
});
// Call the submit to begin the file download.
form.submit({
target: '_blank', // Avoids leaving the page.
params: params
});
// Clean-up the form after 100 milliseconds.
// Once the submit is called, the browser does not care anymore with the form object.
Ext.defer(function(){
form.close();
}, 100);
}
答案 1 :(得分：5)
我在尝试在Ajax调用中下载Excel文件时遇到了类似的问题，我用这种方式解决了这个问题：
制作标准的sumbit而不是Ajax。
var form = Ext.create('Ext.form.Panel', { // this wolud be your form
standardSubmit: true, // this is the important part
url: '../ObtenerArchivoAdjuntoServlet'
});
form.submit({
params: {
nombreArchivo: nombreArchivo
}
});
在此之后，您将能够返回所需的文件。
答案 2 :(得分：2)
我认为你可以采取更容易的解决方案。忘记ajax，只需让普通的旧js为你打开文件：
window.open('http://whatever.com/count?client='+client+'&start='+start+'&end='+end)
这将打开一个新标签并从那里开始下载。
答案 3 :(得分：1)
在提取/阅读很多帖子之后，我设法让这个简单的方法起作用。
Ext.create('Ext.form.Panel', {
renderTo: Ext.getBody(),
standardSubmit: true,
url: 'URL'
}).submit({params: {'PARAM1': param1, 'PARAM2': param2}});
答案 4 :(得分：0)
我只需要宣传ajax请求的成功功能：
window.open('urltothefile.ext')
答案 5 :(得分：0)
以下代码用于使用extjs 5或6下载文件。将以下代码添加到方法并调用此按钮以执行按钮操作。这将直接下载文件，而不是在新标签页中打开。
像这样使用iframe：
/**
* prints the file
*/
printReport: function () {
var url = 'downloadURL';
Ext.Ajax.request({
url: url,
method: 'GET',
autoAbort: false,
success: function(result) {
if(result.status == 204) {
Ext.Msg.alert('Empty Report', 'There is no data');
} else if(result.status == 200) {
Ext.DomHelper.append(Ext.getBody(), {
tag: 'iframe',
frameBorder: 0,
width: 0,
height: 0,
css: 'display:none;visibility:hidden;height:0px;',
src: url
});
}
},
failure: function() {
//failure here will automatically
//log the user out as it should
}
});
}
选项：2 如果要在新选项卡中打开文件
/**
* open file in tab
*/
openReport: function () {
var url = 'downloadURL';
Ext.Ajax.request({
url: url,
method: 'GET',
autoAbort: false,
success: function(result) {
if(result.status == 204) {
Ext.Msg.alert('Empty Report', 'There is no data');
} else if(result.status == 200) {
var win = window.open('', '_blank');
win.location = url;
win.focus();
}
},
failure: function() {
//failure here will automatically
//log the user out as it should
}
});
}
答案 6 :(得分：0)
您无法使用ajax下载文件。我在extjs中实现了文件下载，就像ajax一样。请参阅博客ajaxlikefiledownload。
FileDownload.downloadFile = function(arguments) {
var url = arguments['url'];
var params = arguments['params'];
var successCallback = arguments['success'];
var failureCallback = arguments['failure'];
var body = Ext.getBody();
var frame = body.createChild({
tag:'iframe',
cls:'x-hidden',
id:'hiddenframe-frame',
name:'iframe'
});
var form = body.createChild({
tag:'form',
cls:'x-hidden',
id:'hiddenform-form',
action: url,
method: 'POST',
target:'iframe'
});
if (params)
{
for (var paramName in params)
{
form.createChild({
tag:'input',
cls:'x-hidden',
id:'hiddenform-'+paramName,
type: 'text',
text: params[paramName],
target:'iframe',
value: params[paramName],
name: paramName
});
}
}
form.dom.submit();
FileDownload.isFinished(successCallback,failureCallback);
};
FileDownload.isFinished = function(successCallback,failureCallback) {
//Check if file is started downloading
if (Ext.util.Cookies.get('fileDownload') && Ext.util.Cookies.get('fileDownload')=='true' ) {
//Remove cookie call success callback
Ext.util.Cookies.set('fileDownload', null, new Date("January 1, 1970"),application.contextPath+'/');
Ext.util.Cookies.clear('fileDownload',application.contextPath+'/');
successCallback();
return;
}
//Check for error / IF any error happens then frame will load with content
try {
if(Ext.getDom('hiddenframe-frame').contentDocument.body.innerHTML.length>0){
Ext.util.Cookies.set('fileDownload', null, new Date("January 1, 1970"),application.contextPath+'/');
Ext.util.Cookies.clear('fileDownload',application.contextPath+'/');
failureCallback();
//Cleanup
Ext.getDom('hiddenframe-frame').contentDocument.body.innerHTML = "";
return;
}
}
catch (e) {
console.log(e);
}
console.log('polling..');
// If we are here, it is not loaded. Set things up so we check the status again in 100 milliseconds
window.setTimeout('FileDownload.isFinished('+successCallback+','+failureCallback+')', 100);
};
用法：
FileDownload.downloadFile({
url : url,
params : params,
success : function(){
//Success call back here
},
failure : function(){
//Failure callbak here
}
});
在http响应中，您需要添加一个cookie nammed fileDownload = true