默认情况下,在受版本控制的存储空间(Bucket)中调用HeadObject接口仅获取文件(Object)当前版本的meta信息。

说明 如果Object的当前版本为删除标记,则返回404 Not Found。请求参数中指定versionId则返回指定版本Object的meta信息。

示例代码

以下代码用于获取文件元信息:

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 阿里云账号AccessKey拥有所有API的访问权限,风险很高。强烈建议您创建并使用RAM用户进行API访问或日常运维,请登录RAM控制台创建RAM用户。
        String accessKeyId = "yourAccessKeyId";
        String accessKeySecret = "yourAccessKeySecret";
        // 填写Bucket名称,例如examplebucket。
        String bucketName = "examplebucket";
        // 填写Object的完整路径。Object完整路径中不能包含Bucket名称。
        String objectName = "exampledir/object";
        // 指定归档类文件的versionId。
        String versionId = "CAEQMxiBgICAof2D0BYiIDJhMGE3N2M1YTI1NDQzOGY5NTkyNTI3MGYyMzJm****";

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

        try {
            // 获取指定versionId文件的部分元信息。
            GenericRequest getSimplifiedObjectMetaRequest = new GenericRequest(bucketName, objectName, versionId);
            SimplifiedObjectMeta objectMeta = ossClient.getSimplifiedObjectMeta(getSimplifiedObjectMetaRequest);
            System.out.println(objectMeta.getSize());
            System.out.println(objectMeta.getETag());
            System.out.println(objectMeta.getLastModified());

            // 获取指定versionId文件的全部元信息。
            GenericRequest getObjectMetadataRequest = new GenericRequest(bucketName, objectName, versionId);
            ObjectMetadata metadata = ossClient.getObjectMetadata(getObjectMetadataRequest);
            System.out.println(metadata.getContentType());
            System.out.println(metadata.getLastModified());
            System.out.println(metadata.getExpirationTime());
        } 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();
            }
        }
    }
}

相关文档

关于获取文件元信息的API接口说明,请参见HeadObjectGetObjectMeta