企业级项目开发中都会有文件、图片、视频等文件上传并能够访问的场景，对于初学者Demo可能会直接存储在应用服务器上；对于传统项目可能会单独搭建FastDFS、MinIO等文件服务来实现存储，这种方案可能对于企业成本较小，但缺点也是很多，例如：1、增加技术人员的运维和维护成本，2、规模越来越大时需要硬件的支持，且存在文件丢失风险，3、服务器没有CDN，用户访问网站图片加载慢用户体验不好。
所以，一般上规模的项目、或者追求用户体验的项目可能会考虑使用第三方的云服务来存储，市场主流厂商有：七牛云、阿里云OSS、腾讯云COS等，具体采用哪种存储方案需结合项目、规模、成本等因素，综合考量确定。
因为用的腾讯云服务器，为了方便统一管理，所以直接用了腾讯云的COS对象存储服务，下面是基于SpringBoot和腾讯云COS提供的Java SDK快速对接实现文件上传功能。
https://console.cloud.tencent.com/cos5
cos: baseUrl: fxxxxxa-1xxxxx1.cos.ap-shanghai.myqcloud.com accessKey: AKxxxxxxxxxxxxxxxxxxxxxxxxxCF secretKey: oKxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxni regionName: ap-shanghai bucketName: fxxxxxa-1xxxxx1 folderPrefix: /files
@Data
@Component
@ConfigurationProperties(prefix = "cos")
public class COSConfig {
private String baseUrl;
private String accessKey;
private String secretKey;
private String regionName;
private String bucketName;
private String folderPrefix;
}
/**
* 腾讯云COS文件上传工具类
*/
@Slf4j
public class COSClientUtil {
/**
* 获取配置信息
*/
private static COSConfig cosConfig = SpringBeanUtils.getBean(COSConfig.class);
/**
* 初始化用户身份信息
*/
private static COSCredentials cred = new BasicCOSCredentials(cosConfig.getAccessKey(), cosConfig.getSecretKey());
/**
* 设置bucket的区域
*/
private static ClientConfig clientConfig = new ClientConfig(new Region(cosConfig.getRegionName()));
/**
* 生成COS客户端
*/
private static COSClient cosClient = new COSClient(cred, clientConfig);
/**
* 上传文件
*
* @param file
* @return
* @throws Exception
*/
public static String upload(MultipartFile file) throws Exception {
String date = DateUtils.formateDate(new Date(), "yyyy-MM-dd");
String originalFilename = file.getOriginalFilename();
long nextId = IdGenerator.getFlowIdWorkerInstance().nextId();
String name = nextId + originalFilename.substring(originalFilename.lastIndexOf("."));
String folderName = cosConfig.getFolderPrefix() + "/" + date + "/";
String key = folderName + name;
File localFile = null;
try {
localFile = transferToFile(file);
String filePath = uploadFileToCOS(localFile, key);
log.info("upload COS successful: {}", filePath);
return filePath;
} catch (Exception e) {
throw new Exception("文件上传失败");
} finally {
localFile.delete();
}
}
/**
* 上传文件到COS
*
* @param localFile
* @param key
* @return
*/
private static String uploadFileToCOS(File localFile, String key) throws InterruptedException {
PutObjectRequest putObjectRequest = new PutObjectRequest(cosConfig.getBucketName(), key, localFile);
ExecutorService threadPool = Executors.newFixedThreadPool(8);
// 传入一个threadPool, 若不传入线程池, 默认TransferManager中会生成一个单线程的线程池
TransferManager transferManager = new TransferManager(cosClient, threadPool);
// 返回一个异步结果Upload, 可同步的调用waitForUploadResult等待upload结束, 成功返回UploadResult, 失败抛出异常
Upload upload = transferManager.upload(putObjectRequest);
UploadResult uploadResult = upload.waitForUploadResult();
transferManager.shutdownNow();
cosClient.shutdown();
String filePath = cosConfig.getBaseUrl() + uploadResult.getKey();
return filePath;
}
/**
* 用缓冲区来实现这个转换, 即创建临时文件
* 使用 MultipartFile.transferTo()
*
* @param multipartFile
* @return
*/
private static File transferToFile(MultipartFile multipartFile) throws IOException {
String originalFilename = multipartFile.getOriginalFilename();
String prefix = originalFilename.split("\\.")[0];
String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
File file = File.createTempFile(prefix, suffix);
multipartFile.transferTo(file);
return file;
}
}
/**
* 腾讯云COS上传
*
* @param file
* @return
* @throws Exception
*/
@PostMapping(value = "/cosUpload")
public ResponseEntity cosUpload(MultipartFile file) throws Exception {
String filePath = COSClientUtil.upload(file);
UploadDTO dto = UploadDTO.builder().filePath(filePath).build();
return ResultVOUtil.success(dto);
}
