Question

我目前正在努力将图片从“ http://localhost:8080/download”下载到我的Android，以便将其设置为图片。我发现了一个类似的问题：Download image from 'download url' Android，但这并不能解决我的问题。

我的代码：

//Webserver Download Function
@RequestMapping(value = "/download", method = RequestMethod.GET, produces = MediaType.IMAGE_PNG_VALUE)
    public ResponseEntity<Object> downloadFile() throws FileNotFoundException {
        File img = new File("D:\\Apprenticeship\\Work\\Projekte\\apli\\__Abschlussprojekt\\visitor.png");

        InputStreamResource resource = new InputStreamResource(new FileInputStream(img));
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.add("Content-Disposition", String.format("attachment; filename=\"%s\"", img.getName()));
        httpHeaders.add("Cache-Control", "no-cache, no-store, must-revalidate");
        httpHeaders.add("Pragma", "no-cache");
        httpHeaders.add("Expires", "0");

        return ResponseEntity.ok().headers(httpHeaders).contentLength(img.length()).contentType(MediaType.parseMediaType("image/png")).body(resource);
    }

我想念什么？

Answer 1

请尝试以下代码。那就是通常在我的应用程序中实现文件下载的方式。

@RequestMapping(value = "/download", method = RequestMethod.GET, produces = MediaType.IMAGE_PNG_VALUE)
public @ResponseBody void downloadFile(HttpServletResponse response) throws IOException {
    File img = new File("D:\\Apprenticeship\\Work\\Projekte\\apli\\__Abschlussprojekt\\visitor.png");

    response.setContentType("image/png");
    response.setHeader("Content-Length", String.valueOf(img.length()));
    response.setHeader("Content-Disposition", String.format("attachment; filename=\"%s\"", img.getName()));
    response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
    response.setHeader("Pragma", "no-cache");
    response.setHeader("Expires", "0");

    try ( FileInputStream in = new FileInputStream(img)) {
         FileCopyUtils.copy(in, response.getOutputStream());
    }
}

从Spring Framework中的下载URL下载图像

1 个答案: