FileתMultipartFile

File tempFile = File.createTempFile(UUIDUtil.getuuId(), ".docx");
    FileInputStream ins = new FileInputStream(tempFile);
    byte[] bytes = StreamUtils.copyToByteArray(ins);
    MultipartFile multipartFile =
        new MockMultipartFile(
            "file", tempFile.getName(), ContentType.APPLICATION_OCTET_STREAM.toString(), bytes);