java - Spring Boot 如何做查看 PDF

Question

这里我创建了用于查看 pdf 部分的 API。 这是我的 API 网址:http://localhost:8082/api/layout/samePdfview/20 问题是当我第一次调用这个 API url 时， 并显示一些错误消息

“java.io.FileNotFoundException:类路径资源[static/layout/pdf/20190215163504_editedLandscape_layoutPort.pdf]无法打开，因为它不存在 ”

当停止服务器并再次运行时，它正在工作，并且显示 pdf。 我找不到问题所在，请任何人帮助我

@RequestMapping(value = "/diffPdfview/{id}", method = RequestMethod.GET ,produces ={MediaType.APPLICATION_PDF_VALUE} )

    public ResponseEntity<InputStreamResource> getDiffPdf(@PathVariable("id") int id, HttpServletResponse response) throws IOException {
        List<LayoutEntity> getdiffPdf = layoutRepo.findViewImages(id,1);//status=1
        String diffPdf = getdiffPdf.get(0).getdLayoutPath();
        String diffPdfStr = diffPdf;
        diffPdfStr = diffPdfStr.substring(diffPdfStr.lastIndexOf("/"));

        return ResponseEntity
                .ok()
                .body(new InputStreamResource(new ClassPathResource("static/layout/pdf"+diffPdfStr).getInputStream()));
    }

Answer 1

试试这个:

 public ResponseEntity<byte[]> getDiffPdf(@PathVariable("id") int id, HttpServletResponse response) throws IOException {
    List<LayoutEntity> getdiffPdf = layoutRepo.findViewImages(id,1);//status=1
    String diffPdf = getdiffPdf.get(0).getdLayoutPath();
    String diffPdfStr = diffPdf;
    diffPdfStr = diffPdfStr.substring(diffPdfStr.lastIndexOf("/"));
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.parseMediaType("application/pdf"));
    String filename = diffPdfStr;
    headers.add("content-disposition", "inline;filename=" + filename); 
    headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");
    Path pdfPath = Paths.get("static/layout/pdf"+diffPdfStr);            //"/path/to/file.pdf"
    byte[] pdf = Files.readAllBytes(pdfPath);
    ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(pdf, headers, HttpStatus.OK);
    return response;
    }