MongoDB GridFS文件上传下载_mongo chunk下载

MongoDB GridFS支持大文件存储：

GridFS用于存储和恢复那些超过16M（BSON文件限制）的文件(如：图片、音频、视频等)；

GridFS 也是文件存储的一种方式，但是它是存储在MonoDB的集合中;

GridFS 可以更好的存储大于16M的文件；

GridFS 会将大文件对象分割成多个小的chunk(文件片段),一般为256k/个,每个chunk将作为MongoDB的一个文档(document)被存储在chunks集合中；

每个文件的实际内容被存在chunks(二进制数据)中,和文件有关的meta数据(filename,content_type,还有用户自定义的属性)将会被存在files集合中。

spring-boot-starter-data-mongodb 基于GridFS实现文件的上传下载

application配置文件

server:
  port: 9001
spring:
  data:
    mongodb:
      uri: mongodb://root:123456@127.0.0.1:27017/fileInfo?readPreference=secondary&authSource=admin
  jackson:
    default-property-inclusion: non_null
  servlet:
    multipart:
      max-file-size: 10MB  #单个文件上传大小
      max-request-size: 100MB   #单次请求文件上传大小
  http:
    encoding:
      charset: UTF-8

自定义实体类记录上传文件的相关信息

@Data
@AllArgsConstructor
@NoArgsConstructor
@Document(collection = "tbl_data_record")
public class FileMetaDomain implements Serializable {
 
    private static final long serialVersionUID = 7733095063283270367L;
 
    @Id
    private String id;
 
    /* 文件信息存储在数据库中的uuid */ private List<Object> fileIds;
 
    /* 源文件名 */ private String fileName;
 
    /* 文件类型 */ private String contentType;
 
    /* 文件大小 */ private long size;
 
    /* 更新日期 */ private LocalDate updateTime = LocalDate.now();
 
    /* 创建日期 */ private LocalDate createTime = LocalDate.now();
 
    public FileMetaDomain(String id, String fileName, String contentType, long size){
        this.id = id; this.fileName = fileName;
        this.contentType = contentType;this.size = size;
    }
}

Dao层接口

@Repository
public interface GridFSRepository extends MongoRepository<FileMetaDomain,String> {
 
    @Query("{'fileName': ?0}")
    FileMetaDomain findByFileName(String fileName);
}

Service逻辑处理

public interface GridFsService {
 
    String saveFile(MultipartFile file) throws IOException;
 
    void downLoad(HttpServletResponse response, String fileName);
}

实现类

@Slf4j
@Service
public class GridFSServiceImpl implements GridFsService {
 
    private final MongoTemplate mongoTemplate;
 
    private final GridFSRepository repository;
 
    private final GridFsTemplate gridFsTemplate;
 
    @Autowired
    public GridFSServiceImpl(GridFSRepository repository, MongoTemplate mongoTemplate, GridFsTemplate gridFsTemplate) {
        this.repository = repository;
        this.mongoTemplate = mongoTemplate;
        this.gridFsTemplate = gridFsTemplate;
    }
 
    @Override
    public String saveFile(MultipartFile file) throws IOException {
        //源文件名
        String originalFilename = file.getOriginalFilename();
        //文件类型
        String contentType = file.getContentType();
        //文件大小
        long size = file.getSize();
        MongoDatabase db = mongoTemplate.getDb();
        GridFSBucket gridFSBucket = GridFSBuckets.create(db);
        ObjectId objectId = gridFSBucket.uploadFromStream(originalFilename, file.getInputStream());
        FileMetaDomain fileMetaDomain = new FileMetaDomain(objectId.toString(),originalFilename,contentType,size);
        FileMetaDomain fileMeta = repository.save(fileMetaDomain);
        return fileMeta.getId();
    }
 
    @Override
    public void downLoad(HttpServletResponse response, String fileName){
        FileMetaDomain fileMetaDomain = repository.findByFileName(fileName);
        Assert.notNull(fileMetaDomain,"当前下载的文件未上传到服务器");
        Query query = new Query();
        query.addCriteria(Criteria.where("filename").is(fileName));
        GridFSFile file = gridFsTemplate.findOne(query);
        MongoDatabase db = mongoTemplate.getDb();
        try {
            //文件名转码,支持中文文件名下载
            fileName = URLEncoder.encode(fileName,"UTF-8");
            response.setContentType("application/vnd.ms-excel;charset=utf-8");
            response.setHeader("Content-Disposition","attachment;filename="+fileName);
            ServletOutputStream outputStream = response.getOutputStream();
            GridFSBuckets.create(db).downloadToStream(file.getObjectId(),outputStream);
            outputStream.flush();
            outputStream.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

文件上传下载接口

@Slf4j
@RestController
@RequestMapping("/file")
public class GridFSController {
 
    private final GridFsService service;
 
    @Autowired
    public GridFSController(GridFsService service) {
        this.service = service;
    }
 
    @PostMapping("/upload")
    @ResponseBody
    public ResponseEntity<String> upload(@RequestParam("file") MultipartFile file){
        try {
            if(ObjectUtils.isEmpty(file)){
                return ResponseEntity.ok().body("上传文件不能为空");
            }else {
                return ResponseEntity.ok().body(service.saveFile(file));
            }
        }catch (Exception e){
            log.error("[Upload Failed]",e);
            return ResponseEntity.badRequest().body(e.getMessage());
        }
    }
 
    @GetMapping("/download")
    public ResponseEntity<String> download(HttpServletResponse response, @RequestParam("fileName")String fileName){
        try {
            service.downLoad(response,fileName);
            return ResponseEntity.ok().body("SUCCESS");
        }catch (Exception e){
            log.error("[Download Failed]",e.getMessage());
            return ResponseEntity.badRequest().body(e.getMessage());
        }
    }
}