从Spring引导休息服务下载文件 [英] download a file from Spring boot rest service

问题描述

我正在尝试从Spring引导休息服务下载文件。

I am trying to download a file from a Spring boot rest service.

@RequestMapping(path="/downloadFile",method=RequestMethod.GET)
    @Consumes(MediaType.APPLICATION_JSON_VALUE)
    public  ResponseEntity<InputStreamReader> downloadDocument(
                String acquistionId,
                String fileType,
                Integer expressVfId) throws IOException {
        File file2Upload = new File("C:\\Users\\admin\\Desktop\\bkp\\1.rtf");
        HttpHeaders headers = new HttpHeaders();
        headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
        headers.add("Pragma", "no-cache");
        headers.add("Expires", "0");
        InputStreamReader i = new InputStreamReader(new FileInputStream(file2Upload));
        System.out.println("The length of the file is : "+file2Upload.length());

        return ResponseEntity.ok().headers(headers).contentLength(file2Upload.length())
                .contentType(MediaType.parseMediaType("application/octet-stream"))
                .body(i);
        }

当我尝试从浏览器下载文件时，它开始下载，但总是失败。导致下载失败的服务有什么问题吗？

When I tried to download the file from the browser, it starts the download, but always fails. Is there anything wrong with the service which is causing the download to fail?

推荐答案

选项1 使用 InputStreamResource

资源实现给定的 InputStream 。

只有在其他特定资源实现不适用时才应使用。特别是，在可能的情况下，更喜欢ByteArrayResource或任何基于文件的资源实现。

Should only be used if no other specific Resource implementation is > applicable. In particular, prefer ByteArrayResource or any of the file-based Resource implementations where possible.

@RequestMapping(path = "/download", method = RequestMethod.GET)
public ResponseEntity<Resource> download(String param) throws IOException {

    // ...

    InputStreamResource resource = new InputStreamResource(new FileInputStream(file));

    return ResponseEntity.ok()
            .headers(headers)
            .contentLength(file.length())
            .contentType(MediaType.parseMediaType("application/octet-stream"))
            .body(resource);
}

---

Option2 正如InputStreamResource的文档建议的那样 - 使用 ByteArrayResource ：

---

Option2 as the documentation of the InputStreamResource suggests - using a ByteArrayResource:

@RequestMapping(path = "/download", method = RequestMethod.GET)
public ResponseEntity<Resource> download(String param) throws IOException {

    // ...

    Path path = Paths.get(file.getAbsolutePath());
    ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));

    return ResponseEntity.ok()
            .headers(headers)
            .contentLength(file.length())
            .contentType(MediaType.parseMediaType("application/octet-stream"))
            .body(resource);
}

这篇关于从Spring引导休息服务下载文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！