我在服务器端有一个Struts2操作用于文件下载。
<action name="download" class="com.xxx.DownAction">
<result name="success" type="stream">
<param name="contentType">text/plain</param>
<param name="inputName">imageStream</param>
<param name="contentDisposition">attachment;filename={fileName}</param>
<param name="bufferSize">1024</param>
</result>
</action>
然而，当我使用jQuery调用动作时:
$.post(
"/download.action",{
para1:value1,
para2:value2
....
},function(data){
console.info(data);
}
);
在Firebug中，我看到数据是用二进制流检索的。我想知道如何打开文件下载窗口，用户可以在本地保存文件?
如何下载一个文件后收到它的AJAX
当文件创建了很长一段时间，你需要显示PRELOADER时，这很方便
例如，当提交一个web表单:
<script>
$(function () {
$('form').submit(function () {
$('#loader').show();
$.ajax({
url: $(this).attr('action'),
data: $(this).serialize(),
dataType: 'binary',
xhrFields: {
'responseType': 'blob'
},
success: function(data, status, xhr) {
$('#loader').hide();
// if(data.type.indexOf('text/html') != -1){//If instead of a file you get an error page
// var reader = new FileReader();
// reader.readAsText(data);
// reader.onload = function() {alert(reader.result);};
// return;
// }
var link = document.createElement('a'),
filename = 'file.xlsx';
// if(xhr.getResponseHeader('Content-Disposition')){//filename
// filename = xhr.getResponseHeader('Content-Disposition');
// filename=filename.match(/filename="(.*?)"/)[1];
// filename=decodeURIComponent(escape(filename));
// }
link.href = URL.createObjectURL(data);
link.download = filename;
link.click();
}
});
return false;
});
});
</script>
可选函数被注释掉以简化示例。
不需要在服务器上创建临时文件。
jQuery v2.2.4 OK。旧版本将会有一个错误:
Uncaught DOMException: Failed to read the 'responseText' property from 'XMLHttpRequest': The value is only accessible if the object's 'responseType' is '' or 'text' (was 'blob').
我创建了一个小函数作为解决方案(灵感来自@JohnCulviner插件):
// creates iframe and form in it with hidden field,
// then submit form with provided data
// url - form url
// data - data to form field
// input_name - form hidden input name
function ajax_download(url, data, input_name) {
var $iframe,
iframe_doc,
iframe_html;
if (($iframe = $('#download_iframe')).length === 0) {
$iframe = $("<iframe id='download_iframe'" +
" style='display: none' src='about:blank'></iframe>"
).appendTo("body");
}
iframe_doc = $iframe[0].contentWindow || $iframe[0].contentDocument;
if (iframe_doc.document) {
iframe_doc = iframe_doc.document;
}
iframe_html = "<html><head></head><body><form method='POST' action='" +
url +"'>" +
"<input type=hidden name='" + input_name + "' value='" +
JSON.stringify(data) +"'/></form>" +
"</body></html>";
iframe_doc.open();
iframe_doc.write(iframe_html);
$(iframe_doc).find('form').submit();
}
演示点击事件:
$('#someid').on('click', function() {
ajax_download('/download.action', {'para1': 1, 'para2': 2}, 'dataname');
});
在上面添加一些东西来下载文件
下面是一些生成字节数组的java spring代码
@RequestMapping(value = "/downloadReport", method = { RequestMethod.POST })
public ResponseEntity<byte[]> downloadReport(
@RequestBody final SomeObejct obj, HttpServletResponse response) throws Exception {
OutputStream out = new ByteArrayOutputStream();
// write something to output stream
HttpHeaders respHeaders = new HttpHeaders();
respHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);
respHeaders.add("X-File-Name", name);
ByteArrayOutputStream bos = (ByteArrayOutputStream) out;
return new ResponseEntity<byte[]>(bos.toByteArray(), respHeaders, HttpStatus.CREATED);
}
现在在javascript代码中使用filesver .js，可以下载带有下面代码的文件
var json=angular.toJson("somejsobject");
var url=apiEndPoint+'some url';
var xhr = new XMLHttpRequest();
//headers('X-File-Name')
xhr.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 201) {
var res = this.response;
var fileName=this.getResponseHeader('X-File-Name');
var data = new Blob([res]);
saveAs(data, fileName); //this from FileSaver.js
}
}
xhr.open('POST', url);
xhr.setRequestHeader('Authorization','Bearer ' + token);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.responseType = 'arraybuffer';
xhr.send(json);
以上将下载文件
I found a fix that while it's not actually using ajax it does allow you to use a javascript call to request the download and then get a callback when the download actually starts. I found this helpful if the link runs a server side script that takes a little bit to compose the file before sending it. so you can alert them that it's processing, and then when it does finally send the file remove that processing notification. which is why I wanted to try to load the file via ajax to begin with so that I could have an event happen when the file is requested and another when it actually starts downloading.
js在首页
function expdone()
{
document.getElementById('exportdiv').style.display='none';
}
function expgo()
{
document.getElementById('exportdiv').style.display='block';
document.getElementById('exportif').src='test2.php?arguments=data';
}
iframe
<div id="exportdiv" style="display:none;">
<img src="loader.gif"><br><h1>Generating Report</h1>
<iframe id="exportif" src="" style="width: 1px;height: 1px; border:0px;"></iframe>
</div>
然后是另一个文件:
<!DOCTYPE html>
<html>
<head>
<script>
function expdone()
{
window.parent.expdone();
}
</script>
</head>
<body>
<iframe id="exportif" src="<?php echo "http://10.192.37.211/npdtracker/exportthismonth.php?arguments=".$_GET["arguments"]; ?>"></iframe>
<script>document.getElementById('exportif').onload= expdone;</script>
</body></html>
我认为有一种方法可以使用js读取数据，这样就不需要php了。但我不知道它的手，我正在使用的服务器支持php，所以这对我有用。我想分享一下，也许能帮到别人。
