用springboot+hdfs+mysql实现文件上传下载

下面是Spring Boot集成HDFS和MySQL实现文件上传和下载的示例代码：

1. 配置文件

application.properties:

#HDFS配置
hadoop.hdfs.uri=hdfs://localhost:9000
hadoop.hdfs.user.name=hadoop

#MySQL配置
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#上传文件存储路径
upload.path=/usr/local/uploads/

2. 实体类

FileEntity.java:

@Entity
@Table(name = "file")
@Data
public class FileEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false)
    private String name;

    @Column(nullable = false)
    private String path;

    @Column(nullable = false)
    private String type;

    @Column(nullable = false)
    private Long size;

    @Column(name = "create_time", nullable = false)
    private Date createTime;
}

3. HDFS工具类

HdfsUtils.java:

@Component
public class HdfsUtils {
    @Value("${hadoop.hdfs.uri}")
    private String hdfsUri;

    @Value("${hadoop.hdfs.user.name}")
    private String hdfsUserName;

    private FileSystem fileSystem;

    @PostConstruct
    public void init() throws IOException {
        Configuration configuration = new Configuration();
        configuration.set("fs.defaultFS", hdfsUri);
        fileSystem = FileSystem.get(configuration);
    }

    public void uploadFile(String srcPath, String destPath) throws IOException {
        Path src = new Path(srcPath);
        Path dst = new Path(destPath);
        fileSystem.copyFromLocalFile(src, dst);
    }

    public void downloadFile(String srcPath, String destPath) throws IOException {
        Path src = new Path(srcPath);
        Path dst = new Path(destPath);
        fileSystem.copyToLocalFile(src, dst);
    }

    public void deleteFile(String path) throws IOException {
        Path src = new Path(path);
        fileSystem.delete(src, true);
    }
}

4. 文件服务接口

FileService.java:

public interface FileService {
    FileEntity save(MultipartFile file) throws IOException;

    Resource loadFileAsResource(Long id) throws FileNotFoundException;

    void delete(Long id) throws IOException;

    Page<FileEntity> findByPage(int pageNum, int pageSize);
}

5. 文件服务实现类

FileServiceImpl.java:

@Service
public class FileServiceImpl implements FileService {
    private final String uploadPath = System.getProperty("user.dir") + "/uploads/";

    @Autowired
    private FileRepository fileRepository;

    @Autowired
    private HdfsUtils hdfsUtils;

    @Override
    public FileEntity save(MultipartFile file) throws IOException {
        String fileName = file.getOriginalFilename();
        String fileType = fileName.substring(fileName.lastIndexOf(".") + 1);
        String filePath = uploadPath + fileName;
        File destFile = new File(filePath);
        file.transferTo(destFile);

        String hdfsFilePath = "/upload/" + fileName;
        hdfsUtils.uploadFile(filePath, hdfsFilePath);

        FileEntity fileEntity = new FileEntity();
        fileEntity.setName(fileName);
        fileEntity.setPath(hdfsFilePath);
        fileEntity.setType(fileType);
        fileEntity.setSize(file.getSize());
        fileEntity.setCreateTime(new Date());
        return fileRepository.save(fileEntity);
    }

    @Override
    public Resource loadFileAsResource(Long id) throws FileNotFoundException {
        FileEntity fileEntity = fileRepository.findById(id).orElseThrow(() -> new FileNotFoundException("文件不存在"));
        String filePath = fileEntity.getPath();
        String fileName = fileEntity.getName();
        Path path = new Path(filePath);
        try {
            FileSystem fs = FileSystem.get(URI.create(hdfsUtils.getHdfsUri()), hdfsUtils.getConfiguration(),
                    hdfsUtils.getHdfsUserName());
            FSDataInputStream inputStream = fs.open(path);
            return new InputStreamResource(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
            throw new FileNotFoundException(e.getMessage());
        }
    }

    @Override
    public void delete(Long id) throws IOException {
        FileEntity fileEntity = fileRepository.findById(id).orElseThrow(() -> new FileNotFoundException("文件不存在"));
        String filePath = fileEntity.getPath();
        hdfsUtils.deleteFile(filePath);
        fileRepository.deleteById(id);
    }

    @Override
    public Page<FileEntity> findByPage(int pageNum, int pageSize) {
        Pageable pageable = PageRequest.of(pageNum, pageSize, Sort.Direction.DESC, "createTime");
        return fileRepository.findAll(pageable);
    }
}

6. 文件控制器

FileController.java:

@RestController
@RequestMapping("/file")
public class FileController {
    @Autowired
    private FileService fileService;

    @PostMapping
    public ResponseEntity<?> uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
        FileEntity fileEntity = fileService.save(file);
        URI location = ServletUriComponentsBuilder.fromCurrentRequest().path("/{id}")
                .buildAndExpand(fileEntity.getId()).toUri();
        return ResponseEntity.created(location).build();
    }

    @GetMapping("/{id}")
    public ResponseEntity<Resource> downloadFile(@PathVariable Long id) throws FileNotFoundException {
        Resource resource = fileService.loadFileAsResource(id);
        return ResponseEntity.ok().header(HttpHeaders.CONTENT_DISPOSITION,
                "attachment; filename=\"" + resource.getFilename() + "\"").body(resource);
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<?> deleteFile(@PathVariable Long id) throws IOException {
        fileService.delete(id);
        return ResponseEntity.noContent().build();
    }

    @GetMapping("/list")
    public ResponseEntity<Page<FileEntity>> getList(@RequestParam(defaultValue = "0") int pageNum,
                                                     @RequestParam(defaultValue = "10") int pageSize) {
        Page<FileEntity> page = fileService.findByPage(pageNum, pageSize);
        return ResponseEntity.ok(page);
    }
}

7. 文件存储仓库

FileRepository.java:

public interface FileRepository extends JpaRepository<FileEntity, Long> {
}

这样，文件上传和下载的功能就完成了。启动应用程序，可以使用POSTMAN或其他客户端上传、下载和删除文件了。