Delete objects using OSS SDK for Java 1.0 - Object Storage Service

Usage notes

In this topic, the public endpoint of the China (Hangzhou) region is used. To access OSS from other Alibaba Cloud services in the same region, use an internal endpoint. For details about supported regions and endpoints, see Regions and Endpoints.
In this topic, access credentials are obtained from environment variables. For more information, see Configure access credentials.
This topic demonstrates creating an OSSClient instance with an OSS endpoint. For alternative configurations, such as using a custom domain or authenticating with credentials from Security Token Service (STS), see Client configuration.
To delete an object, you must have the oss:DeleteObject permission. For more information, see Grant a custom policy.

Delete a single object

The following code deletes an object named exampleobject.txt from a bucket named examplebucket:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;

public class Demo {
    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the full path of the object. Do not include the bucket name in the full path of the object. 
        String objectName = "exampleobject.txt";
        // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        // Call the shutdown method to release associated resources when the OSSClient is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Delete the object or the directory. Before you delete a directory, make sure that the directory does not contain objects. 
            ossClient.deleteObject(bucketName, objectName);
        } 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();
            }
        }
    }
}

Delete multiple objects at a time

You can delete up to 1,000 objects at a time by name, by prefix, or by directory.

You can also configure lifecycle rules to automatically delete objects. For more information, see Last modification time lifecycle rules.

Parameters

Request parameters

Parameter	Description	Method
Keys	The objects that you want to delete.	setKeys(List<String>)
quiet	The return mode for delete results: verbose (default): Returns all deleted objects. Used when quiet is set to false or not configured. quiet: When set to true, the response does not include deleted objects.	setQuiet(boolean)
encodingType	The encoding method for object names in the response. Only URL encoding is supported.	setEncodingType(String)

Response parameters

Parameter

Description

Method

deletedObjects

The result of the delete operation.

In verbose mode, returns all deleted objects, including specified objects that did not exist.
In quiet mode, the response does not include the deleted objects.

List<String> getDeletedObjects()

encodingType

The encoding method for object names. If empty, object names are not encoded.

getEncodingType()

Delete multiple objects with specified names

The following code deletes multiple objects by name:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.DeleteObjectsRequest;
import com.aliyun.oss.model.DeleteObjectsResult;
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 {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        // Call the shutdown method to release associated resources when the OSSClient is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Delete the objects. 
            // Specify the full paths of the multiple objects that you want to delete. Do not include the bucket name in the full paths of the objects. 
            List<String> keys = new ArrayList<String>();
            keys.add("exampleobjecta.txt");
            keys.add("testfolder/sampleobject.txt");
            keys.add("exampleobjectb.txt");

            DeleteObjectsResult deleteObjectsResult = ossClient.deleteObjects(new DeleteObjectsRequest(bucketName).withKeys(keys).withEncodingType("url"));
            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();
            }
        } 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();
            }
        }
    }
}

Delete multiple objects with the specified object name prefix or in the specified directory

The following code deletes objects by prefix or deletes an entire directory:

Warning

If the prefix is not specified or is set to NULL, all objects in the bucket are deleted. Specify prefixes carefully.

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
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 {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the prefix of the names of the objects that you want to delete. If you want to delete all objects whose names contain the src prefix, set the prefix to src. After you set the prefix to src, all non-directory objects whose names contain the src prefix, the src directory, and all objects in the src directory are deleted. 
        String prefix = "src";
        // If you want to delete only the src directory and all objects in the directory, set the prefix to src/. 
        // String prefix = "src/";
        // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        // Call the shutdown method to release associated resources when the OSSClient is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // List all objects whose names contain the specified prefix and delete the objects. 
            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();
            } 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();
            }
        }
    }
}

FAQ

How do I verify that an object is deleted?

If deleteObject of OSSClient returns no exception, the object is deleted. To confirm, call the doesObjectExist method of OSSClient. A return value of false confirms deletion. For more information, see Determine whether an object exists using OSS SDK for Java.

References

Delete a single object

For more information about the API operation that you can call to delete a single object, see DeleteObject.
Delete multiple objects
- Complete sample code for deleting multiple objects: GitHub.
- For more information about the API operation that you can call to delete multiple objects, see DeleteMultipleObjects.