java.nio.file.InvalidPathException：格式错误的输入或输入包含不可映射的字符

Question

我正在尝试从Spring端点下载pdf文件。我尝试过：

@RequestMapping("/download_files/{merchant_id}")
    public ResponseEntity<byte[]> downloadFile(@PathVariable("merchant_id") Integer merchant_id) throws IOException {
     File initialFile = new File("/opt/1/www.pdf");
        InputStream in = FileUtils.openInputStream(initialFile);

        final HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_PDF);

        return new ResponseEntity<byte[]>(IOUtils.toByteArray(in), headers, HttpStatus.CREATED);
    }

但是我得到了错误：

2019-08-20 21:02:25,658 INFO  [stdout] (default task-307) java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /opt/1/25084 BRP (BrookfieldDC.com Site Architecture & Creative?Phase 2) Autoresponders (1).pdf

您知道如何解决此问题吗？