API | Operation | Description |
Querying object metadata | Queries the metadata of an object. |
// Create a COSClient instance, which is used to initiate requests later.COSClient createCOSClient() {// Set the user identity information.// Log in to the [CAM console](https://console.tencentcloud.com/cam/capi) to view and manage the `SecretId` and `SecretKey` of your project.String secretId = "SECRETID";String secretKey = "SECRETKEY";COSCredentials cred = new BasicCOSCredentials(secretId, secretKey);// `ClientConfig` contains the COS client configuration for subsequent COS requests.ClientConfig clientConfig = new ClientConfig();// Set the bucket region.// For more information on COS regions, please visit https://www.tencentcloud.com/document/product/436/6224.clientConfig.setRegion(new Region("COS_REGION"));// Set the request protocol, `http` or `https`.// For 5.6.53 and earlier versions, HTTPS is recommended.// Starting from 5.6.54, HTTPS is used by default.clientConfig.setHttpProtocol(HttpProtocol.https);// The following settings are optional.// Set the read timeout period, which is 30s by default.clientConfig.setSocketTimeout(30*1000);// Set the connection timeout period, which is 30s by default.clientConfig.setConnectionTimeout(30*1000);// If necessary, set the HTTP proxy, IP, and port.clientConfig.setHttpProxyIp("httpProxyIp");clientConfig.setHttpProxyPort(80);// Generate a COS client.return new COSClient(cred, clientConfig);}
// Create a COSClient instance, which is used to initiate requests later.COSClient createCOSClient() {// Here, the temporary key information is needed.// For how to generate temporary keys, please visit https://www.tencentcloud.com/document/product/436/14048.String tmpSecretId = "TMPSECRETID";String tmpSecretKey = "TMPSECRETKEY";String sessionToken = "SESSIONTOKEN";COSCredentials cred = new BasicSessionCredentials(tmpSecretId, tmpSecretKey, sessionToken);// `ClientConfig` contains the COS client configuration for subsequent COS requests.ClientConfig clientConfig = new ClientConfig();// Set the bucket region.// For more information on COS regions, please visit https://www.tencentcloud.com/document/product/436/6224.clientConfig.setRegion(new Region("COS_REGION"));// Set the request protocol, `http` or `https`.// For 5.6.53 and earlier versions, HTTPS is recommended.// Starting from 5.6.54, HTTPS is used by default.clientConfig.setHttpProtocol(HttpProtocol.https);// The following settings are optional.// Set the read timeout period, which is 30s by default.clientConfig.setSocketTimeout(30*1000);// Set the connection timeout period, which is 30s by default.clientConfig.setConnectionTimeout(30*1000);// If necessary, set the HTTP proxy, IP, and port.clientConfig.setHttpProxyIp("httpProxyIp");clientConfig.setHttpProxyPort(80);// Generate a COS client.return new COSClient(cred, clientConfig);}
HEAD Object
) is used to query object metadata.public ObjectMetadata getObjectMetadata(String bucketName, String key)throws CosClientException, CosServiceException;
// Before using the COS API, ensure that the process contains a COSClient instance. If such an instance does not exist, create one.// For the detailed code, see "Simple Operations -> Creating a COSClient instance" on the current page.COSClient cosClient = createCOSClient();// Enter the bucket name in the format of `BucketName-APPID`.String bucketName = "examplebucket-1250000000";// Object key, the unique ID of an object in a bucket. For more information, please see [Object Key](https://www.tencentcloud.com/document/product/436/13324).String key = "exampleobject";try {ObjectMetadata objectMetadata = cosClient.getObjectMetadata(bucketName, key);System.out.println(objectMetadata.getCrc64Ecma());System.out.println(objectMetadata.getLastModified());} catch (CosServiceException e) {e.printStackTrace();} catch (CosClientException e) {e.printStackTrace();}// After confirming that the process does not use the COSClient instance anymore, close it.cosClient.shutdown();
Parameter | Description | Type |
bucketName | String | |
key | Object key, the unique identifier of an object in a bucket. For example, in the object endpoint examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/do/picture.jpg , the object key is doc/picture.jpg . For details, see ObjectKey | String |
ObjectMetadata
, including the user-defined headers and object metadata such as the ETag.CosClientException
or CosServiceException
exception will be thrown. For more information, please see Troubleshooting.ObjectMetadata
class is used to record the metadata of an object. The main members are described as follows:Member Name | Description | Type |
httpExpiresDate | Cache expiration time, which is the same value as that of the Expires field in HTTP response header | Date |
ongoingRestore | Indicates the object is being restored from ARCHIVE | Boolean |
userMetadata | User-defined metadata prefixed with x-cos-meta- | Map<String, String> |
metadata | Headers other than user-defined metadata | Map<String, String> |
restoreExpirationTime | Expiration time for an object copy restored from ARCHIVE | Date |
Was this page helpful?