Object Storage Service (OSS) provides the multipart upload feature. Multipart upload allows you to split a large object into multiple parts to upload. After these parts are uploaded, you can call the CompleteMultipartUpload operation to combine the parts into a complete object.
Usage notes
This topic describes how to perform multipart upload to upload a local file. For more information about how to perform multipart upload to upload a network or data stream, see How do I upload data streams in parts by using OSS SDK for Java?.
In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions, endpoints and open ports.
In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.
To perform multipart upload, you must have the
oss:PutObjectpermission. For more information, see Attach a custom policy to a RAM user.
Procedure
To upload a local file by using multipart upload, perform the following steps:
Initiate a multipart upload task.
Call the ossClient.initiateMultipartUpload method to obtain an upload ID that is unique in OSS.
Upload parts.
Call the ossClient.uploadPart method to upload the parts.
NoteIn a multipart upload task, part numbers are used to identify the relative positions of the parts in an object. If you upload a part that has the same part number as an existing part, the existing part is overwritten by the uploaded part.
OSS includes the MD5 hash of each uploaded part in the ETag header in the response.
OSS calculates the MD5 hash of uploaded parts and compares the MD5 hash with the MD5 hash that is calculated by OSS SDK for Java. If the two hashes are different, OSS returns the InvalidDigest error code.
Complete the multipart upload task.
After all parts are uploaded, call the ossClient.completeMultipartUpload method to combine these parts into a complete object.
For more information about multipart upload and the scenarios in which multipart upload can be performed, see Multipart upload.
Examples
The following sample code provides an example on how to implement a multipart upload task by following the multipart upload process:
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.internal.Mimetypes;
import com.aliyun.oss.model.*;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
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 full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object.
String objectName = "exampledir/exampleobject.txt";
// Specify the full path of the local file that you want to upload.
String filePath = "D:\\localpath\\examplefile.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.
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
// Create an InitiateMultipartUploadRequest object.
InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, objectName);
// The following sample code provides an example on how to specify the request headers when you initiate a multipart upload task:
ObjectMetadata metadata = new ObjectMetadata();
// metadata.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard.toString());
// Specify the caching behavior of the web page for the object.
// metadata.setCacheControl("no-cache");
// Specify the name of the downloaded object.
// metadata.setContentDisposition("attachment;filename=oss_MultipartUpload.txt");
// Specify the content encoding format of the object.
// metadata.setContentEncoding(OSSConstants.DEFAULT_CHARSET_NAME);
// Specify whether existing objects are overwritten by objects that have the same names when the multipart upload task is initiated. In this example, this parameter is set to true, which indicates that existing objects cannot be overwritten by objects with the same names.
// metadata.setHeader("x-oss-forbid-overwrite", "true");
// Specify the server-side encryption method that you want to use to encrypt each part of the object that you want to upload.
// metadata.setHeader(OSSHeaders.OSS_SERVER_SIDE_ENCRYPTION, ObjectMetadata.KMS_SERVER_SIDE_ENCRYPTION);
// Specify the algorithm that you want to use to encrypt the object. If you do not specify this parameter, the object is encrypted by using AES-256.
// metadata.setHeader(OSSHeaders.OSS_SERVER_SIDE_DATA_ENCRYPTION, ObjectMetadata.KMS_SERVER_SIDE_ENCRYPTION);
// Specify the ID of the customer master key (CMK) that is managed by Key Management Service (KMS).
// metadata.setHeader(OSSHeaders.OSS_SERVER_SIDE_ENCRYPTION_KEY_ID, "9468da86-3509-4f8d-a61e-6eab1eac****");
// Specify the storage class of the object.
// metadata.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard);
// Specify one or more tags for the object.
// metadata.setHeader(OSSHeaders.OSS_TAGGING, "a:1");
// request.setObjectMetadata(metadata);
// Specify ContentType based on the object type. If you do not specify this parameter, the default value of ContentType is used, which is application/oct-srream.
if (metadata.getContentType() == null) {
metadata.setContentType(Mimetypes.getInstance().getMimetype(new File(filePath), objectName));
}
// Initiate the multipart upload task.
InitiateMultipartUploadResult upresult = ossClient.initiateMultipartUpload(request);
// Obtain the upload ID.
String uploadId = upresult.getUploadId();
// Cancel the multipart upload task or list uploaded parts based on the upload ID.
// If you want to cancel a multipart upload task based on the upload ID, obtain the upload ID after you call the InitiateMultipartUpload operation to initiate the multipart upload task.
// If you want to list the uploaded parts in a multipart upload task based on the upload ID, obtain the upload ID after you call the InitiateMultipartUpload operation to initiate the multipart upload task but before you call the CompleteMultipartUpload operation to complete the multipart upload task.
// System.out.println(uploadId);
// partETags is a set of PartETags. A PartETag consists of the part number and ETag of an uploaded part.
List<PartETag> partETags = new ArrayList<PartETag>();
// Specify the size of each part, which is used to calculate the number of parts of the object. Unit: bytes.
final long partSize = 1 * 1024 * 1024L; // Set the part size to 1 MB.
// Calculate the number of parts based on the size of the uploaded data. In the following sample code, a local file is used as an example to describe how to use the File.length() method to obtain the size of the uploaded data.
final File sampleFile = new File(filePath);
long fileLength = sampleFile.length();
int partCount = (int) (fileLength / partSize);
if (fileLength % partSize != 0) {
partCount++;
}
// Upload all parts.
for (int i = 0; i < partCount; i++) {
long startPos = i * partSize;
long curPartSize = (i + 1 == partCount) ? (fileLength - startPos) : partSize;
UploadPartRequest uploadPartRequest = new UploadPartRequest();
uploadPartRequest.setBucketName(bucketName);
uploadPartRequest.setKey(objectName);
uploadPartRequest.setUploadId(uploadId);
// Specify the input stream of the multipart upload task.
// In the following sample code, a local file is used as an example to describe how to create a FIleInputstream and use the InputStream.skip() method to skip the specified data.
InputStream instream = new FileInputStream(sampleFile);
instream.skip(startPos);
uploadPartRequest.setInputStream(instream);
// Specify the part size. The size of each part except for the last part must be greater than or equal to 100 KB.
uploadPartRequest.setPartSize(curPartSize);
// Specify part numbers. Each part has a part number that ranges from 1 to 10,000. If the part number that you specify does not fall within the specified range, OSS returns the InvalidArgument error code.
uploadPartRequest.setPartNumber( i + 1);
// Parts are not necessarily uploaded in order and can be uploaded from different OSS clients. OSS sorts the parts based on the part numbers and combines the parts into a complete object.
UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
// Each time a part is uploaded, OSS returns a result that contains the PartETag of the part. The PartETag is stored in partETags.
partETags.add(uploadPartResult.getPartETag());
}
// Create a CompleteMultipartUploadRequest object.
// When you call the CompleteMultipartUpload operation, you must provide all valid PartETags. After OSS receives the PartETags, OSS verifies all parts one by one. After all parts are verified, OSS combines these parts into a complete object.
CompleteMultipartUploadRequest completeMultipartUploadRequest =
new CompleteMultipartUploadRequest(bucketName, objectName, uploadId, partETags);
// The following sample code provides an example on how to configure the access control list (ACL) of the object when you initiate a multipart upload task:
// completeMultipartUploadRequest.setObjectACL(CannedAccessControlList.Private);
// Specify whether to list all parts that are uploaded by using the current upload ID. For OSS SDK for Java 3.14.0 and later, you can set PartETags in CompleteMultipartUploadRequest to null only when you list all parts uploaded to the OSS server to combine the parts into a complete object.
// Map<String, String> headers = new HashMap<String, String>();
// If you set x-oss-complete-all to yes in the request, OSS lists all parts that are uploaded by using the current upload ID, sorts the parts by part number, and then performs the CompleteMultipartUpload operation.
// If you set x-oss-complete-all to yes in the request, the request body cannot be specified. If you specify the request body, an error is reported.
// headers.put("x-oss-complete-all","yes");
// completeMultipartUploadRequest.setHeaders(headers);
// Complete the multipart upload task.
CompleteMultipartUploadResult completeMultipartUploadResult = ossClient.completeMultipartUpload(completeMultipartUploadRequest);
System.out.println(completeMultipartUploadResult.getETag());
} 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();
}
}
}
}Cancel a multipart upload task
You can call the ossClient.abortMultipartUpload method to cancel a multipart upload task. If you cancel a multipart upload task, you cannot use the upload ID to upload parts. The uploaded parts are deleted.
The following sample code provides an example on how to cancel a multipart upload task:
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 {
// 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. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object.
String objectName = "exampledir/exampleobject.txt";
// Specify the upload ID. Example: 0004B999EF518A1FE585B0C9360D****. You can obtain the upload ID from the response to the InitiateMultipartUpload operation.
String uploadId = "0004B999EF518A1FE585B0C9360D****";
// 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.
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
// Cancel the multipart upload task.
AbortMultipartUploadRequest abortMultipartUploadRequest =
new AbortMultipartUploadRequest(bucketName, objectName, uploadId);
ossClient.abortMultipartUpload(abortMultipartUploadRequest);
} 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();
}
}
}
}List uploaded parts
You can call the ossClient.listParts method to list all parts that are uploaded by using a specific upload ID.
List uploaded parts by using simple list
The following sample code provides an example on how to use simple list to list uploaded parts:
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 { // 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. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object. String objectName = "exampledir/exampleobject.txt"; // Specify the upload ID. Example: 0004B999EF518A1FE585B0C9360D****. You can obtain the upload ID from the response to the InitiateMultipartUpload operation. You must obtain the upload ID before you call the CompleteMultipartUpload operation to complete the multipart upload task. String uploadId = "0004B999EF518A1FE585B0C9360D****"; // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List uploaded parts. ListPartsRequest listPartsRequest = new ListPartsRequest(bucketName, objectName, uploadId); // Specify the upload ID. //listPartsRequest.setUploadId(uploadId); // Set the maximum number of parts that can be displayed on each page to 100. By default, 1,000 parts are listed. listPartsRequest.setMaxParts(100); // Specify the position from which the list operation starts. Only the parts whose part numbers are greater than the value of this parameter are listed. listPartsRequest.setPartNumberMarker(2); PartListing partListing = ossClient.listParts(listPartsRequest); for (PartSummary part : partListing.getParts()) { // Obtain the part numbers. System.out.println(part.getPartNumber()); // Obtain the size of each part. System.out.println(part.getSize()); // Obtain the ETag of each part. System.out.println(part.getETag()); // Obtain the last modified time of each part. System.out.println(part.getLastModified()); } } 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(); } } } }List all uploaded parts
By default, you can list up to 1,000 uploaded parts at a time by using listParts. If you want to list more than 1,000 uploaded parts, run the following sample code:
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 { // 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. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object. String objectName = "exampledir/exampleobject.txt"; // Specify the upload ID. Example: 0004B999EF518A1FE585B0C9360D****. You can obtain the upload ID from the response to the InitiateMultipartUpload operation. You must obtain the upload ID before you call the CompleteMultipartUpload operation to complete the multipart upload task. String uploadId = "0004B999EF518A1FE585B0C9360D****"; // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List all uploaded parts. PartListing partListing; ListPartsRequest listPartsRequest = new ListPartsRequest(bucketName, objectName, uploadId); do { partListing = ossClient.listParts(listPartsRequest); for (PartSummary part : partListing.getParts()) { // Obtain the part numbers. System.out.println(part.getPartNumber()); // Obtain the size of each part. System.out.println(part.getSize()); // Obtain the ETag of each part. System.out.println(part.getETag()); // Obtain the last modified time of each part. System.out.println(part.getLastModified()); } // Specify the position from which the list operation starts. Only the parts whose part numbers are greater than the value of this parameter are listed. listPartsRequest.setPartNumberMarker(partListing.getNextPartNumberMarker()); } while (partListing.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(); } } } }List all uploaded parts by page
The following sample code provides an example on how to list all uploaded parts by page and specify the maximum number of parts to list per page:
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 { // 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. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object. String objectName = "exampledir/exampleobject.txt"; // Specify the upload ID. Example: 0004B999EF518A1FE585B0C9360D****. You can obtain the upload ID from the response to the InitiateMultipartUpload operation. You must obtain the upload ID before you call the CompleteMultipartUpload operation to complete the multipart upload task. String uploadId = "0004B999EF518A1FE585B0C9360D****"; // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List all uploaded parts by page. PartListing partListing; ListPartsRequest listPartsRequest = new ListPartsRequest(bucketName, objectName, uploadId); // Set the maximum number of parts to list per page to 100. listPartsRequest.setMaxParts(100); do { partListing = ossClient.listParts(listPartsRequest); for (PartSummary part : partListing.getParts()) { // Obtain the part numbers. System.out.println(part.getPartNumber()); // Obtain the size of each part. System.out.println(part.getSize()); // Obtain the ETag of each part. System.out.println(part.getETag()); // Obtain the last modified time of each part. System.out.println(part.getLastModified()); } listPartsRequest.setPartNumberMarker(partListing.getNextPartNumberMarker()); } while (partListing.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(); } } } }
List multipart upload tasks
You can use the ossClient.listMultipartUploads method to list all ongoing multipart upload tasks. Ongoing multipart upload tasks include tasks that have been initiated but are not completed or are canceled. The following table describes the parameters that you can configure to list multipart upload tasks.
Parameter | Description | Method |
prefix | The prefix that must be included in the names of the returned objects. If you use a prefix for a query, the returned object names contain the prefix. | ListMultipartUploadsRequest.setPrefix(String prefix) |
delimiter | The character used to group object names. Objects whose names contain a substring from the specified prefix to the first occurrence of the delimiter are returned as a single element. | ListMultipartUploadsRequest.setDelimiter(String delimiter) |
maxUploads | The maximum number of multipart upload tasks that you want to return for the current list. Maximum value: 1000. Default value: 1000. | ListMultipartUploadsRequest.setMaxUploads(Integer maxUploads) |
keyMarker | Specifies that all multipart upload tasks with objects whose names are alphabetically after the value of the keyMarker parameter are included in the list. You can use this parameter together with the uploadIdMarker parameter to specify the position from which the returned results start. | ListMultipartUploadsRequest.setKeyMarker(String keyMarker) |
uploadIdMarker | The position from which the returned results start. You can use this parameter together with the keyMarker parameter. If you do not configure the keyMarker parameter, the uploadIdMarker parameter is invalid. If you configure the keyMarker parameter, the query results include the following items:
| ListMultipartUploadsRequest.setUploadIdMarker(String uploadIdMarker) |
List multipart upload tasks by using simple list
The following sample code provides an example on how to use simple list to list multipart upload tasks:
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 { // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List multipart upload tasks. By default, 1,000 parts are listed. ListMultipartUploadsRequest listMultipartUploadsRequest = new ListMultipartUploadsRequest(bucketName); MultipartUploadListing multipartUploadListing = ossClient.listMultipartUploads(listMultipartUploadsRequest); for (MultipartUpload multipartUpload : multipartUploadListing.getMultipartUploads()) { // Obtain the upload ID of each multipart upload task. System.out.println(multipartUpload.getUploadId()); // Obtain the name of each multipart upload task. System.out.println(multipartUpload.getKey()); // Obtain the point in time at which each multipart upload task is initiated. System.out.println(multipartUpload.getInitiated()); } } 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(); } } } }If the value of the isTruncated parameter in the response is true, the values of nextKeyMarker and nextUploadIdMarker are returned to specify the position from which the next read operation starts. If the response does not contain all multipart upload tasks, list multipart upload tasks by page.
List all multipart upload tasks
By default, you can call the listMultipartUploads operation to list up to 1,000 parts at a time. The following sample code provides an example on how to list all multipart upload tasks when the number of parts is greater than 1,000:
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 { // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List multipart upload tasks. MultipartUploadListing multipartUploadListing; ListMultipartUploadsRequest listMultipartUploadsRequest = new ListMultipartUploadsRequest(bucketName); do { multipartUploadListing = ossClient.listMultipartUploads(listMultipartUploadsRequest); for (MultipartUpload multipartUpload : multipartUploadListing.getMultipartUploads()) { // Obtain the upload ID of each multipart upload task. System.out.println(multipartUpload.getUploadId()); // Obtain the object name. System.out.println(multipartUpload.getKey()); // Obtain the point in time at which each multipart upload task is initiated. System.out.println(multipartUpload.getInitiated()); } listMultipartUploadsRequest.setKeyMarker(multipartUploadListing.getNextKeyMarker()); listMultipartUploadsRequest.setUploadIdMarker(multipartUploadListing.getNextUploadIdMarker()); } while (multipartUploadListing.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(); } } } }List all multipart upload tasks by page
The following sample code provides an example on how to list all multipart upload tasks by page:
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 { // 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. ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration(); clientBuilderConfiguration.setSignatureVersion(SignVersion.V4); OSS ossClient = OSSClientBuilder.create() .endpoint(endpoint) .credentialsProvider(credentialsProvider) .clientConfiguration(clientBuilderConfiguration) .region(region) .build(); try { // List multipart upload tasks. MultipartUploadListing multipartUploadListing; ListMultipartUploadsRequest listMultipartUploadsRequest = new ListMultipartUploadsRequest(bucketName); // Specify the number of multipart upload tasks to list on each page. listMultipartUploadsRequest.setMaxUploads(50); do { multipartUploadListing = ossClient.listMultipartUploads(listMultipartUploadsRequest); for (MultipartUpload multipartUpload : multipartUploadListing.getMultipartUploads()) { // Obtain the upload ID of each multipart upload task. System.out.println(multipartUpload.getUploadId()); // Obtain the name of each multipart upload task. System.out.println(multipartUpload.getKey()); // Obtain the point in time at which each multipart upload task is initiated. System.out.println(multipartUpload.getInitiated()); } listMultipartUploadsRequest.setKeyMarker(multipartUploadListing.getNextKeyMarker()); listMultipartUploadsRequest.setUploadIdMarker(multipartUploadListing.getNextUploadIdMarker()); } while (multipartUploadListing.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(); } } } }
References
For the complete sample code that is used to perform multipart upload, visit GitHub.
A multipart upload involves three API operations. For more information about the operations, see the following topics:
For more information about the API operation that you can call to cancel a multipart upload task, see AbortMultipartUpload.
For more information about the API operation that you can call to list uploaded parts, see ListParts.
For more information about the API operation that you can call to list all ongoing multipart upload tasks, see ListMultipartUploads. Ongoing multipart upload tasks include tasks that have been initiated but are not completed or are canceled.