java 使用 Spring Boot 和 Thymeleaf 创建文件下载链接
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/29816121/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Creating a file download link using Spring Boot and Thymeleaf
提问by shyam
This might sound like a trivial question, but after hours of searching I am yet to find an answer to this. The problem, as far as I understand, is that I am trying to return a FileSystemResourcefrom the controller and Thymeleaf expects me to supply a Stringresource using which it will render the next page. But since I am returning a FileSystemResource, I get the following error:
这听起来像是一个微不足道的问题，但经过数小时的搜索，我还没有找到答案。据我所知，问题在于我试图FileSystemResource从控制器返回 a并且 Thymeleaf 希望我提供一个String资源，它将使用它来呈现下一页。但是由于我返回了 a FileSystemResource，因此出现以下错误：
org.thymeleaf.exceptions.TemplateInputException: Error resolving template "products/download", template might not exist or might not be accessible by any of the configured Template Resolvers
The controller mapping I have used is:
我使用的控制器映射是：
@RequestMapping(value="/products/download", method=RequestMethod.GET)
public FileSystemResource downloadFile(@Param(value="id") Long id) {
Product product = productRepo.findOne(id);
return new FileSystemResource(new File(product.getFileUrl()));
}
My HTML link looks something like this:
我的 HTML 链接如下所示：
<a th:href="${'products/download?id=' + product.id}"><span th:text="${product.name}"></span></a>
I don't want to be redirected anywhere, I just need the file downloaded once the link is clicked. Is this actually the right implementation? I'm not sure.
我不想被重定向到任何地方，我只需要在单击链接后下载文件。这实际上是正确的实现吗？我不确定。
回答by Leandro Carracedo
You need to change the th:hrefto look like:
您需要将其更改th:href为如下所示：
<a th:href="@{|/products/download?id=${product.id}|}"><span th:text="${product.name}"></span></a>
Then also you need to change your controller and include the @ResponseBodyannotation:
然后您还需要更改控制器并包含@ResponseBody注释：
@RequestMapping(value="/products/download", method=RequestMethod.GET)
@ResponseBody
public FileSystemResource downloadFile(@Param(value="id") Long id) {
Product product = productRepo.findOne(id);
return new FileSystemResource(new File(product.getFileUrl()));
}
回答by Padmanabhan Velu
Have a href url like
有一个像这样的href url
<a th:href="@{|/download?id=${obj.id}|}">download</a>
Then In controller define like below to write the file to the response object.
然后在控制器中定义如下将文件写入响应对象。
@RequestMapping(value="/download", method=RequestMethod.GET)
public void downloadFile(@Param(value="id") Long id,HttpServletResponse response) {
try {
Ticket ticket = this.findById(id);
String fileName = Paths.get(property.getFileLocation()).resolve(ticket.getFilePath()).toString();
response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
String headerKey = "Content-Disposition";
String headerValue = String.format("attachment; filename=\"%s\"", fileName);
response.setHeader(headerKey, headerValue);
FileInputStream inputStream;
try {
inputStream = new FileInputStream(fileName);
try {
int c;
while ((c = inputStream.read()) != -1) {
response.getWriter().write(c);
}
} finally {
if (inputStream != null)
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
response.getWriter().close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
回答by Andrei Epure
Thymeleaf is very well documented, you can find about literal substitutions(what Leandro showed above) in the manual - section 4.7
Thymeleaf 有很好的文档记录，您可以在手册中找到文字替换（Leandro 上面展示的内容） -第 4.7 节
Excerpt from the manual
摘自手册
<span th:text="|Welcome to our application, ${user.name}!|">
回答by Vetras
for me, the answer from @leandro-carracedo worked but the browser would just list the file contents, not download.
对我来说，@leandro-carracedo 的回答有效，但浏览器只会列出文件内容，而不是下载。
This fixed that:
这修复了：
<a download="results.csv" th:href=... </a>
