如何使用Java SDK管理目錄 - Object Storage Service

與傳統檔案系統中的層級結構不同，OSS內部使用扁平結構儲存資料。即所有資料均以對象（Object）的形式儲存在儲存空間（Bucket）中。為方便管理，OSS控制台將所有以正斜線（/）結尾的對象顯示為目錄，實作類別似於目錄的準系統。您可以通過目錄的層次來組織檔案，實現分組並簡化許可權管理。

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，請參見訪問網域名稱和資料中心。
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。

建立目錄

以下代碼提供了建立目錄的兩種方式。

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 java.io.ByteArrayInputStream;

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";
        // 填寫通過方式一建立的目錄名稱。
        String dirName = "exampledir/";
        // 填寫通過方式二建立的目錄名稱。
        String dirName2 = "exampledir1/";

        // 建立OSSClient執行個體。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 方式一：通過createDirectory介面直接建立目錄。使用該方法建立目錄前，需要開啟階層命名空間。
            ossClient.createDirectory(bucketName, dirName);

            // 方式二：通過上傳Null 字元串的形式建立目錄。
            ossClient.putObject(bucketName, dirName2, new ByteArrayInputStream("".getBytes()));
        } 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();
            }
        }
    }
}

重新命名目錄

儲存空間開啟階層命名空間後，您可以在該儲存空間中重新命名目錄。

以下代碼將examplebucket中的exampledir目錄重新命名為newexampledir。

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 {
        // yourEndpoint填寫Bucket所在地區對應的Endpoint。以華東1（杭州）為例，Endpoint填寫為https://oss-cn-hangzhou.aliyuncs.com。
        String endPoint = "yourEndpoint";
        // 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";
        // 填寫來源目錄絕對路徑。目錄絕對路徑中不能包含Bucket名稱。
        String sourceDir = "exampledir";
        // 填寫與來源目錄處於同一Bucket中的目標目錄絕對路徑。目錄絕對路徑中不能包含Bucket名稱。
        String destinationDir = "newexampledir";

        // 建立OSSClient執行個體。
        OSS ossClient = new OSSClientBuilder().build(endPoint, credentialsProvider);

        try {
            // 將儲存空間中的來源目錄絕對路徑重新命名為目標目錄絕對路徑。
            RenameObjectRequest renameObjectRequest = new RenameObjectRequest(bucketName, sourceDir, destinationDir);
            ossClient.renameObject(renameObjectRequest);
        } 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();
            }
        }
    }
}

刪除目錄

警告

刪除目錄會同步刪除目錄下包含的子目錄以及所有檔案，請謹慎操作。

您可以使用非遞迴刪除或者遞迴刪除方式刪除儲存空間中的指定目錄。

非遞迴刪除

使用非遞迴方式刪除目錄時，您只能刪除空目錄。

以下代碼用於使用非遞迴方式刪除examplebucket中的exampledir目錄。

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 {
        // yourEndpoint填寫Bucket所在地區對應的Endpoint。以華東1（杭州）為例，Endpoint填寫為https://oss-cn-hangzhou.aliyuncs.com。
        String endPoint = "yourEndpoint";
        // 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。
        String bucketName = "examplebucket";
        // 填寫目錄絕對路徑。目錄絕對路徑中不能包含Bucket名稱。
        String directoryName = "exampledir";

        // 建立OSSClient執行個體。
        OSS ossClient = new OSSClientBuilder().build(endPoint, credentialsProvider);

        try {
            // 刪除目錄，預設為非遞迴刪除。請確保已清空該目錄下的檔案和子目錄。使用該方法刪除錄前，需要開啟階層命名空間。
            DeleteDirectoryRequest deleteDirectoryRequest = new DeleteDirectoryRequest(bucketName, directoryName);
            DeleteDirectoryResult deleteDirectoryResult = ossClient.deleteDirectory(deleteDirectoryRequest);

            // 刪除目錄的絕對路徑。
            System.out.println("delete dir name :" + deleteDirectoryResult.getDirectoryName());
            // 本次刪除的檔案和目錄的總數量。
            System.out.println("delete number:" + deleteDirectoryResult.getDeleteNumber());
        } 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();
            }
        }
    }
}

遞迴刪除

使用遞迴方式刪除目錄時，您可以刪除目錄以及目錄下的檔案和子目錄，請謹慎使用。

以下代碼用於使用遞迴刪除方式刪除examplebucket中的指定目錄及該目錄下的檔案和子目錄。

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.*;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.List;

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";
        // 填寫目錄絕對路徑。目錄絕對路徑中不能包含Bucket名稱。
        String directoryName = "exampledir";
        // 填寫待刪除目錄的完整路徑，完整路徑中不包含Bucket名稱。
        final String prefix = "exampledir/";

        // 建立OSSClient執行個體。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 方法1：使用遍曆listObjects的結果刪除目錄及目錄下的所有檔案。
            String nextMarker = null;
            ObjectListing objectListing = null;
            do {
                ListObjectsRequest listObjectsRequest = new ListObjectsRequest(bucketName)
                        .withPrefix(prefix)
                        .withMarker(nextMarker);

                objectListing = ossClient.listObjects(listObjectsRequest);
                if (objectListing.getObjectSummaries().size() > 0) {
                    List<String> keys = new ArrayList<String>();
                    for (OSSObjectSummary s : objectListing.getObjectSummaries()) {
                        System.out.println("key name: " + s.getKey());
                        keys.add(s.getKey());
                    }
                    DeleteObjectsRequest deleteObjectsRequest = new DeleteObjectsRequest(bucketName).withKeys(keys).withEncodingType("url");
                    DeleteObjectsResult deleteObjectsResult = ossClient.deleteObjects(deleteObjectsRequest);
                    List<String> deletedObjects = deleteObjectsResult.getDeletedObjects();
                    try {
                        for(String obj : deletedObjects) {
                            String deleteObj =  URLDecoder.decode(obj, "UTF-8");
                            System.out.println(deleteObj);
                        }
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                }

                nextMarker = objectListing.getNextMarker();

//            // 方法2：通過deleteDirectory遞迴刪除方式刪除目錄。使用該方法刪除目錄前，需要開啟階層命名空間（中國內地的bucket無法使用）。
//            DeleteDirectoryRequest deleteDirectoryRequest = new DeleteDirectoryRequest(bucketName, directoryName);
//            deleteDirectoryRequest.setDeleteRecursive(true);
//            DeleteDirectoryResult deleteDirectoryResult = ossClient.deleteDirectory(deleteDirectoryRequest);
//
//            // 一次支援刪除的目錄和檔案的總和為100個，當一次未刪除完時，服務端會返回nextDeleteToken，此時您可以使用nextDeleteToken繼續刪除後面的資料。
//            // nextDeleteToken用於服務端找到下一次刪除的起點。
//            String nextDeleteToken = deleteDirectoryResult.getNextDeleteToken();
//            System.out.println("delete next token:" + nextDeleteToken);
//            // 如果您需要使用nextDeleteToken繼續完成目錄下剩餘刪除，則繼續執行下列代碼
//            deleteDirectoryRequest.setNextDeleteToken(nextDeleteToken);
//            deleteDirectoryResult = ossClient.deleteDirectory(deleteDirectoryRequest);

            // 刪除的目錄絕對路徑。
            System.out.println("delete dir name :" + deleteDirectoryResult.getDirectoryName());
            // 本次刪除的檔案和目錄的總數量。
            System.out.println("delete number:" + deleteDirectoryResult.getDeleteNumber());

            } while (objectListing.isTruncated());
        } 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();
            }
        }
    }
}

Object Storage Service：Java管理目錄