基于华为云obs的springMVC文件上传下载，简单demo

使用华为云的obs作为文件服务
使用springdata jpa框架操作数据库

创建springboot项目，添加华为云obs的SDK的maven依赖

     <!-- 开启spring配置类 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><optional>true</optional></dependency><!-- 华为云obs的SDK --><dependency><groupId>com.huaweicloud</groupId><artifactId>esdk-obs-java</artifactId><version>[3.19.7,)</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId></dependency>

版本号[3.19.7,)没有问题，表示自动选择最高版本，最低使用3.19.7版本

自定义配置类，并读取配置

# 华为云 obs地址
obs.endPoint=华为云的obs的endpoint地址
obs.ak=华为云账号的ak
obs.sk=华为云账号的sk
obs.bucket=华为云的obs创建的桶名称，建议在华为云obs控制台创建，也可以使用SDK创建

在pom的依赖中配置开启spring的配置类，创建配置类ObsConfigProperties

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;@Data // lombok注解
@Component // 将此类加载到spring容器中
@ConfigurationProperties(prefix = "obs") // 与配置文件中obs的前缀对应
public class ObsConfigProperties {private String endPoint;private String ak;private String sk;private String bucket;
}

在后面的代码中就可以使用
@Autowired
private static ObsConfigProperties properties;
加载配置信息，也可以使用的@Value("${obs.endPoint}") 方式加载配置

编写文件上传下载的工具类

import com.obs.services.ObsClient;
import com.obs.services.model.ObsObject;
import com.obs.services.model.PutObjectResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import javax.annotation.PostConstruct;
import java.io.IOException;
import java.io.InputStream;/*** 以uuid作为存放在华为云的文件名**/
@Component
public class ObsUtils {private static ObsConfigProperties properties;private static ObsClient obsClient;/*** 通过输入流的方式上传文件* @param url 上传到OBS桶中的路径* @param inputStream* @return*/public static String uploadFile(String url, InputStream inputStream) {PutObjectResult putObjectResult = obsClient.putObject(properties.getBucket(), url, inputStream);int statusCode = putObjectResult.getStatusCode();if (statusCode != 200) {throw new RuntimeException("文件上传异常，http响应码为" + statusCode);}return url;}/*** 根据文件的路径获取文件的输入流** @param url* @return* @throws IOException*/public static InputStream downFile(String url) throws IOException {ObsObject obsObject = obsClient.getObject(properties.getBucket(), url);Long contentLength = obsObject.getMetadata().getContentLength();return obsObject.getObjectContent();}@PostConstructpublic void init() {obsClient = new ObsClient(properties.getAk(), properties.getSk(), properties.getEndPoint());}@Autowiredpublic void setProperties(ObsConfigProperties obsConfigProperties) {properties = obsConfigProperties;}}

注意：

1.工具类一般为静态方法，属于class的，而spring容器是基于对象的，
如果直接写成
@Autowired
private static ObsConfigProperties properties;
static的class字段无法被注入进来
需要使用set方法注入，@Component不能丢
2. 静态字段obsClient的初始化，也需要通过spring在创建对象时完成
@PostConstruct表示spring创建对象前执行的方法

对应数据库的实体类

由于上传文件时会有不同文件相同文件名的情况，上传至obs前需对文件名重命名，这里使用uuid作为文件名，将文件信息放在数据库实体类中，下载时替换文件名


import javax.persistence.*;
import java.io.InputStream;
import java.util.Date;/*** 文件交互时的基本类型**/
@Entity
@Table(name = "t_file", indexes = @Index(name = "file_url_index", columnList = "url", unique = true))
public class ObsBeanDTO {@Id@GeneratedValue(strategy = GenerationType.IDENTITY)private Long id;/*** 用户上传时的文件名*/private String name;/*** 文件类型，根据文件名获取*/private String type;/*** 上传后obs的位置，包含上传后的文件名*/// @Column(name = "url", unique = true)private String url;/*** 华为云obs桶名*/private String bucket;/*** 华为云obs桶名*/@Temporal(TemporalType.TIMESTAMP)private Date dateTime;/*** 文件的输入流*/@Transientprivate InputStream inputStream;@Overridepublic String toString() {return "ObsBeanDTO{" +"id=" + id +", name='" + name + '\'' +", type='" + type + '\'' +", url='" + url + '\'' +", bucket='" + bucket + '\'' +", dateTime=" + dateTime +'}';}public InputStream getInputStream() {return inputStream;}public void setInputStream(InputStream inputStream) {this.inputStream = inputStream;}public Long getId() {return id;}public void setId(Long id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getType() {return type;}public void setType(String type) {this.type = type;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public String getBucket() {return bucket;}public void setBucket(String bucket) {this.bucket = bucket;}public Date getDateTime() {return dateTime;}public void setDateTime(Date dateTime) {this.dateTime = dateTime;}
}

jpa实体类中常见注解说明：https://www.cnblogs.com/jpfss/p/10895336.html

controller层


import com.xq.obs.domain.ObsBeanDTO;
import com.xq.obs.domain.ObsUploadDTO;
import com.xq.service.FileService;
import org.slf4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;import static org.slf4j.LoggerFactory.getLogger;@Controller
public class FileController {private static final Logger logger = getLogger(FileController.class);@AutowiredFileService fileService;@PostMapping("/file")@ResponseBodypublic ObsBeanDTO uploadFile(@RequestParam("file") MultipartFile file) throws IOException {logger.info("upload file,file name -> {}, file.getSize -> {}", file.getOriginalFilename(), file.getSize());ObsUploadDTO obsUploadDTO = new ObsUploadDTO();obsUploadDTO.setName(file.getOriginalFilename());obsUploadDTO.setInputStream(file.getInputStream());ObsBeanDTO obsBeanDTO = fileService.uploadFile(obsUploadDTO);// 清理流，并将实体类的流设为空InputStream inputStream = obsBeanDTO.getInputStream();inputStream.close();obsBeanDTO.setInputStream(null);logger.info("uploadFile is success, obsBeanDTO -> {}", obsBeanDTO);return obsBeanDTO;}@GetMapping("/file")public void downFile(String url, HttpServletResponse response) throws IOException {ObsBeanDTO obsBeanDTO = fileService.downFile(url);InputStream inputStream = obsBeanDTO.getInputStream();byte[] b = new byte[1024];response.setHeader("content-type", "application/octet-stream");response.setContentType("application/octet-stream");response.setHeader("Content-Disposition", "attachment;filename=" + obsBeanDTO.getName());ServletOutputStream outputStream = response.getOutputStream();int len;while ((len=inputStream.read(b)) != -1){outputStream.write(b, 0, len);outputStream.flush();}inputStream.close();obsBeanDTO.setInputStream(null);logger.info("downFile success, obsBeanDTO -> {}", obsBeanDTO);}
}

注意：文件下载时response.setHeader应在流的操作之前设置号，放在流之后，响应头信息会丢失

dao层接口

public interface FileRepository extends JpaRepository<ObsBeanDTO, Long> {public ObsBeanDTO findObsBeanDTOByUrl(String url);
}

service层


import com.xq.converter.ObsDTOConverter;
import com.xq.obs.ObsUtils;
import com.xq.obs.domain.ObsBeanDTO;
import com.xq.obs.domain.ObsUploadDTO;
import com.xq.repository.FileRepository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.io.IOException;
import java.io.InputStream;@Service
public class FileService {private static final Logger logger = LoggerFactory.getLogger(FileService.class);@Autowiredprivate ObsDTOConverter obsDTOConverter;@Autowiredprivate FileRepository fileRepository;public ObsBeanDTO uploadFile(ObsUploadDTO obsUploadDTO) {// 1、创建对应的数据库实体类ObsBeanDTO obsBeanDTO = obsDTOConverter.convertObsBean(obsUploadDTO);// 2、上传至华为云obsObsUtils.uploadFile(obsBeanDTO.getUrl(), obsBeanDTO.getInputStream());logger.info("obsBeanDTO -> {}", obsBeanDTO);// 3、保存进数据库ObsBeanDTO save = fileRepository.save(obsBeanDTO);return save;}public ObsBeanDTO downFile(String url) throws IOException {// 1、数据库查询对应的实体类ObsBeanDTO obsBeanDTO = fileRepository.findObsBeanDTOByUrl(url);// 2、从华为云获取文件流InputStream inputStream = ObsUtils.downFile(url);// 3、封装bean，并返回obsBeanDTO.setInputStream(inputStream);return obsBeanDTO;}
}

其中：ObsDTOConverter为类之间转换器，demo里比较简单，完全可以不用，代码如下：


import com.xq.obs.ObsConfigProperties;
import com.xq.obs.domain.ObsBeanDTO;
import com.xq.obs.domain.ObsUploadDTO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.Date;
import java.util.UUID;@Service
public class ObsDTOConverter {@Autowiredprivate ObsConfigProperties properties;public ObsBeanDTO convertObsBean(ObsUploadDTO obsUploadDTO) {ObsBeanDTO bean = new ObsBeanDTO();bean.setName(obsUploadDTO.getName());bean.setInputStream(obsUploadDTO.getInputStream());bean.setType(makeType(obsUploadDTO.getName()));bean.setUrl(createPath(bean.getType()));bean.setBucket(properties.getBucket());bean.setDateTime(new Date());return bean;}private String createPath(String type) {if (type.isEmpty()) {return "file/" + UUID.randomUUID();}return "file/" + UUID.randomUUID() + "." + type;}private String makeType(String fileName) {// 不能等于0，.txt不是正常的window文件格式int indexOf = fileName.lastIndexOf('.');if (indexOf > 0) {return fileName.substring(indexOf + 1).toLowerCase();}return "";}
}

使用的实体类，下载时需要封装的实体类，demo较简单可以去掉，在实际场景需要的字段可能较多，建议封装一下

public class ObsUploadDTO {private String name;private InputStream inputStream;public String getName() {return name;}public void setName(String name) {this.name = name;}public InputStream getInputStream() {return inputStream;}public void setInputStream(InputStream inputStream) {this.inputStream = inputStream;}
}

github仓库地址：https://github.com/xiongqiang521/jpa-file.git