Spring Boot+MSSQL文件下载损坏问题技术求助

我正在使用Spring Boot、JSP和MSSQL开发文件上传下载功能，目前上传和下载流程可正常运行，但从数据库下载的文件出现损坏情况。原TXT文件内容应为：

testing123
abc

技术信息 #

Spring版本 #

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.0.3-SNAPSHOT</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

控制器代码 #

@RequestMapping(value = "/uploadFile", method = RequestMethod.POST)
public ResponseEntity<Object> upload(@RequestPart(required = false) MultipartFile file) throws IOException {
    try {
        if (file != null) {
            tmDAO.storeFile(file, tm);
        }
        return new ResponseEntity<>("success", HttpStatus.OK);
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }
}

@RequestMapping("/downloadFile/{id}")
public String downloadFile(@PathVariable("id") String id, HttpServletResponse res) throws IOException {
    FileModel fm = tmDAO.getFile(id);
    try {
        File file = new File(fm.getName());
        FileOutputStream fos = new FileOutputStream(file);
        res.setContentLength(fm.getData().length);
        res.setHeader("Content-Disposition", "attachment; filename=" + fm.getName());
        fos.write(fm.getData(), 0, fm.getData().length);
        fos.flush();
        fos.close();
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }
    return "string";
}

服务层代码 #

@Override
public FileModel storeFile(MultipartFile file, TeachingMaterial tm) throws IOException {
    String fileName = StringUtils.cleanPath(file.getOriginalFilename());
    FileModel fileModel = new FileModel(UUID.randomUUID().toString(), tm.getContributor(), fileName,
            file.getContentType(), file.getBytes(), tm.getClassName(), tm.getSubjectName(), tm.getSlots());
    return fileRepo.save(fileModel);
}

@Override
public FileModel getFile(String id) throws IOException {
    Optional<FileModel> fm = fileRepo.findById(id);
    if (fm.isPresent()) {
        return fm.get();
    }
    return null;
}

实体类FileModel.java代码 #

@Entity
@Table(name = "FILES")
public class FileModel {
    @Id
    private String id;
    private String contributor;
    private String name;
    private String type;
    @Lob
    private byte[] data;
    private String className;
    private String subjectName;
    private String slots;

    public FileModel() {
        super();
    }

    public FileModel(String id, String contributor, String name, String type, byte[] data, String className,
                     String subjectName, String slots) {
        super();
        this.id = id;
        this.contributor = contributor;
        this.name = name;
        this.type = type;
        this.data = data;
        this.className = className;
        this.subjectName = subjectName;
        this.slots = slots;
    }
// 省略getter和setter
}

恳请技术人士帮忙解决文件下载损坏的问题。

内容的提问来源于stack exchange，提问作者Zaydon Lim