1.阿里云对象存储OSS

1.对象存储概述

        文件上传，是指将本地图片、视频、音频等文件上传到服务器上，可以供其他用户浏览或下载的过程。文件上传在项目中应用非常广泛，我们经常发抖音、发朋友圈都用到了文件上传功能。

实现文件上传服务，需要有存储的支持，解决方案有以下几种：

存储方式	优点	缺点
直接保存到硬盘	开发便捷，成本低	扩容困难
分布式文件系统	容易实现扩容	开发复杂，需要成熟产品支持
第三方存储服务	开发简单，强大功能， 免维护	付费

2.阿里云对象存储OSS

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2.1 阿里云对象存储OSS配置

2.1.1 创建OSS Bucket

        登录阿里云控制台，申请ECS服务器、申请对象存储OSS、在OSS管理页面创建一个Bucket，Bucket是存储空间的容器，类似于文件夹。选择Bucket的地域、访问权限等设置。

2.1.2 获取AccessKey

        在阿里云控制台获取AccessKey ID和AccessKey Secret，这是访问OSS的凭证。

2.2 项目中使用对象存储OSS

2.2.1 配置AccessKey ID和AccessKey Secret

sky:
  alioss:
    endpoint: oss-cn-chengdu.aliyuncs.com
    access-key-secret: B4CZYBn9zyoKjQzdN5sQNvdxaWJSuy
    access-key-id: LTAI5tAKNiTtEJaPdE3omMi3
    bucket-name: luobeilearn

2.2.2 配置配置类

@Configuration
@Slf4j
public class OssConfiguration {
    @Bean
    @ConditionalOnMissingBean
    public AliOssUtil aliOssUtil(AliOssProperties aliOssProperties){
        log.info("开始上传阿里云文件上传工具类对象：{}",aliOssProperties);
        return new AliOssUtil(aliOssProperties.getEndpoint(),aliOssProperties.getAccessKeyId(),
                aliOssProperties.getAccessKeySecret(),aliOssProperties.getBucketName());
    }
}

2.2.3 创建阿里云属性类

@Component
@ConfigurationProperties(prefix = "sky.alioss")
@Data
public class AliOssProperties {

    private String endpoint;
    private String accessKeyId;
    private String accessKeySecret;
    private String bucketName;

}

2.2.4 创建工具类

@Data
@NoArgsConstructor
@AllArgsConstructor
@Slf4j
public class AliOssUtil {

    private String endpoint;
    private String accessKeyId;
    private String accessKeySecret;
    private String bucketName;

    /**
     * 文件上传
     *
     * @param bytes
     * @param objectName
     * @return
     */
    public String upload(byte[] bytes, String objectName) {

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

        try {
            // 创建PutObject请求。
            ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(bytes));
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }

        //文件访问路径规则 https://BucketName.Endpoint/ObjectName
        StringBuilder stringBuilder = new StringBuilder("https://");
        stringBuilder
                .append(bucketName)
                .append(".")
                .append(endpoint)
                .append("/")
                .append(objectName);

        log.info("文件上传到:{}", stringBuilder.toString());

        return stringBuilder.toString();
    }
}

2.2.5 在Controller中使用

@RestController
@RequestMapping("/admin/common")
@Api(tags = "通用接口")
@Slf4j
public class CommonController {

    @Autowired
    private AliOssUtil aliOssUtil;

    @PostMapping("/upload")
    @ApiOperation("文件上传")
    public Result upload(MultipartFile file){
        log.info("文件上传");
        try {
            //原始文件名
            String originalFilename = file.getOriginalFilename();
            //截取原始文件名后缀
            String substring = originalFilename.substring(originalFilename.lastIndexOf("."));
            String objectName = UUID.randomUUID().toString()+substring;

            String filePath = aliOssUtil.upload(file.getBytes(),objectName);
            return Result.success(filePath);
        } catch (IOException e) {
            log.error("文件上传失败：{}",e);
        }
        return Result.error(MessageConstant.UPLOAD_FAILED);
    }
}