如何使用jQuery AJAX和Spring MVC 3从服务器下载文件 [英] How to download file from server using jQuery AJAX and Spring MVC 3

问题描述

我想从服务器实现上载文件的下载（使用AJAX）。在服务器端我写了代码

  @RequestMapping（value =/ getInvoice / approvalId / {approvalId}，method = RequestMethod.GET）
 public 
 @ResponseBody 
 byte [] getInvoice（@PathVariable（approvalId）整数approvalId，HttpServletResponse响应）throws IOException {
 String fileName = this.approvalService .getFullInvoicePath（approvalId）; 
文件文件=新建文件（fileName）; 
 
 response.setContentType（application / octet-stream）; 
 response.setHeader（Content-Disposition，attachment; filename = \+ file.getName（）+\）; 
 response.setHeader（Pragma，no-cache）; 
 response.setHeader（Cache-Control，no-cache）; 
 response.setContentLength（（int）file.length（））; 
 return FileUtils.readFileToByteArray（file）; 
} 
  

Fiddler2显示回复：

HTTP $ 1.1 $ OK
服务器：Apache-Coyote / 1.1
内容处理：附件; filename =invoice.pdf
Pragma：no-cache
Cache-Control：no-cache
Content-Type：application / octet-stream; charset = UTF-8
内容长度：1028351
日期：2011年7月17日，星期日08:16:41 GMT

％PDF-1.4
％
6 0 obj < / /线性化1 / L 1028351 / O 8 / E 1024254 / N 1 / T 1028185 / H [5056 544]
endobj

xref
6 238
*** FIDDLER：RawDisplay截断为128个字符。右键单击以禁用截断。 ***

如何处理和强制浏览器使用jQuery下载文件？

解决方案

通常使用两个选项，但不包括Ajax。而且jQuery也不是很好的帮助：

选项1：IFrame

将无声IFrame放入您的页面：

 < iframe id =downloadFramestyle =display：none> ;< / iframe中> 
  

当下载应该开始（你没有提到它是如何触发的），使用Javascript可能是jQuery）设置IFrame的URL，这就像你的例子中的 / getInvoice / approvalId / 123 一样：

  var iframe = document.getElementById（downloadFrame）; 
 iframe .src =/ getInvoice / approvalId / 123; 
  

设置IFrame网址应触发浏览器显示下载对话框。

选项2：导航到下载URL

第二个选项更简单。只需浏览下载网址即可。一旦浏览器确定它是一个无法显示的MIME类型，它将显示一个下载对话框。

所以当下载被触发时，执行以下Javascript代码： / p>

  window.location.href =/ getInvoice / approvalId / 123; 
  

注意：

我不知道所有浏览器是否可靠地呈现带有PDF文件的下载对话框。某些浏览器可能会尝试在浏览器本身中显示它。 内容配置标题是有帮助的，但不能保证。

I want to implement downloading (with AJAX) of uploaded file from server. On the server side I wrote the code

@RequestMapping(value = "/getInvoice/approvalId/{approvalId}", method = RequestMethod.GET)
public
@ResponseBody
byte[] getInvoice(@PathVariable("approvalId") Integer approvalId, HttpServletResponse response) throws IOException {
    String fileName = this.approvalService.getFullInvoicePath(approvalId);
    File file = new File(fileName);

    response.setContentType("application/octet-stream");
    response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setContentLength((int) file.length());
    return FileUtils.readFileToByteArray(file);
}

Fiddler2 shows response:

HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Disposition: attachment; filename="invoice.pdf"
Pragma: no-cache
Cache-Control: no-cache
Content-Type: application/octet-stream;charset=UTF-8
Content-Length: 1028351
Date: Sun, 17 Jul 2011 08:16:41 GMT

%PDF-1.4
%����
6 0 obj <</Linearized 1/L 1028351/O 8/E 1024254/N 1/T 1028185/H [ 5056 544]>>
endobj

xref
6 238 
*** FIDDLER: RawDisplay truncated at 128 characters. Right-click to disable truncation. ***

How to handle and force browser to download file using jQuery?

解决方案

Two options are usually used but neither involves Ajax. And jQuery won't be a great help either:

Option 1: IFrame

Place an invisble IFrame into your page:

<iframe id="downloadFrame" style="display:none"></iframe>

When the download should start (you didn't mention how it is triggered), use Javascript (and possibly jQuery) to set the URL for the IFrame, which is something like /getInvoice/approvalId/123 in your case:

var iframe = document.getElementById("downloadFrame");
iframe .src = "/getInvoice/approvalId/123";

Setting the IFrame URL should trigger the browser to present the download dialog.

Option 2: Navigate to the download URL

The second option is even simpler. Just navigate to the download URL. Once the browser figures out it's a MIME type that cannot be displayed, it will present a download dialog.

So when the download is triggered, execute the following Javascript code:

window.location.href = "/getInvoice/approvalId/123";

Note:

I'm not sure if all browser will reliably present a download dialog with PDF files. Some browsers might try to display it within the browser itself. The content disposition header is helpful but no guarantee.

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