軟連結功能用於便捷訪問Bucket內的常用Object。設定軟連結後,您可以使用類似於Windows的捷徑,通過軟連結檔案開啟Object。
注意事項
本文以華東1(杭州)外網Endpoint為例。如果您希望通過與OSS同地區的其他阿里雲產品訪問OSS,請使用內網Endpoint。關於OSS支援的Region與Endpoint的對應關係,請參見OSS訪問網域名稱、資料中心、開放連接埠。
本文以從環境變數讀取存取憑證為例。如何配置訪問憑證,請參見Java配置訪問憑證。
本文以OSS網域名稱建立OSSClient為例。如果您希望通過自訂網域名、STS等方式建立OSSClient,請參見建立OSSClient。
要建立軟連結,您必須具有
oss:PutObject
許可權;要擷取軟連結,您必須具有oss:GetObject
許可權。具體操作,請參見為RAM使用者授權自訂的權限原則。
建立軟連結
以下代碼用於建立軟連結:
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
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以華東1(杭州)為例,其它Region請按實際情況填寫。
String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// 從環境變數中擷取訪問憑證。運行本程式碼範例之前,請確保已設定環境變數OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// 填寫Bucket名稱,例如examplebucket。
String bucketName = "examplebucket";
// 指定軟連結名稱。
String symLink = "yourSymLink";
// 指定軟連結指向的目標Object名稱。
String destinationObjectName = "yourDestinationObjectName";
// 填寫Bucket所在地區。以華東1(杭州)為例,Region填寫為cn-hangzhou。
String region = "cn-hangzhou";
// 建立OSSClient執行個體。
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
// 建立上傳檔案中繼資料。
ObjectMetadata metadata = new ObjectMetadata();
metadata.setContentType("text/plain");
// 設定自訂中繼資料property的值為property-value。
metadata.addUserMetadata("property", "property-value");
// 指定建立軟連結時是否覆蓋同名Object。
// metadata.setHeader("x-oss-forbid-overwrite", "true");
// 指定Object的存取權限。
// metadata.setHeader(OSSHeaders.OSS_OBJECT_ACL, CannedAccessControlList.Default);
// 指定Object的儲存類型。
// metadata.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard);
// 建立CreateSymlinkRequest。
CreateSymlinkRequest createSymlinkRequest = new CreateSymlinkRequest(bucketName, symLink, destinationObjectName);
// 設定中繼資料。
createSymlinkRequest.setMetadata(metadata);
// 建立軟連結。
ossClient.createSymlink(createSymlinkRequest);
} 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();
}
}
}
}
擷取軟連結
擷取軟連結要求您對該軟連結有讀許可權。以下代碼用於擷取軟連結以及軟連結指向的目標檔案名稱:
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
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以華東1(杭州)為例,其它Region請按實際情況填寫。
String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// 從環境變數中擷取訪問憑證。運行本程式碼範例之前,請確保已設定環境變數OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// 填寫Bucket名稱,例如examplebucket。
String bucketName = "examplebucket";
// 填寫軟連結名稱。
String symLink = "yourSymLink";
// 填寫Bucket所在地區。以華東1(杭州)為例,Region填寫為cn-hangzhou。
String region = "cn-hangzhou";
// 建立OSSClient執行個體。
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
// 擷取軟連結以及軟連結指向的目標檔案名稱。
OSSSymlink symbolicLink = ossClient.getSymlink(bucketName, symLink);
System.out.println(symbolicLink.getSymlink());
System.out.println(symbolicLink.getTarget());
System.out.println(symbolicLink.getRequestId());
} 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();
}
}
}
}
相關文檔
關於建立軟連結的API介面說明,請參見PutSymlink。
關於擷取軟連結的API介面說明,請參見GetSymlink。