quick get start

Operation video

Watch the following video to quickly learn how to use the Java SDK.

Create storage space

The storage space is the global namespace of OSS, which is equivalent to a data container and can store several files.

The following code is used to create the storage space.

 import com.aliyun.oss.ClientException; import com.aliyun.oss.OSS; import com.aliyun.oss.OSSClientBuilder; import com.aliyun.oss.OSSException; import com.aliyun.oss.common.auth.CredentialsProviderFactory; import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider; public class Demo { public static void main(String[] args) throws Exception { //Endpoint takes East China 1 (Hangzhou) as an example. Please fill in other regions according to the actual situation. String endpoint = " https://oss-cn-hangzhou.aliyuncs.com "; //Get access credentials from environment variables. Before running this code example, make sure that the environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET have been set. EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider(); //Fill in the bucket name, such as examplebucket. String bucketName = "examplebucket"; //Create an OSSClient instance. OSS ossClient = new OSSClientBuilder().build(endpoint,  credentialsProvider); try { //Create storage space. ossClient.createBucket(bucketName); } 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(); } } } }

Upload file

The following code is used to upload files to OSS through streaming upload.

 import com.aliyun.oss.ClientException; import com.aliyun.oss.OSS; import com.aliyun.oss.OSSClientBuilder; import com.aliyun.oss.OSSException; import com.aliyun.oss.common.auth.CredentialsProviderFactory; import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider; import java.io.ByteArrayInputStream; public class Demo { public static void main(String[] args) throws Exception { //Endpoint takes East China 1 (Hangzhou) as an example. Please fill in other regions according to the actual situation. String endpoint = " https://oss-cn-hangzhou.aliyuncs.com "; //Get access credentials from environment variables. Before running this code example, make sure that the environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET have been set. EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider(); //Fill in the bucket name, such as examplebucket. String bucketName = "examplebucket"; //Fill in the full path of the object, such as exampledir/exampleobject.txt. Bucket names cannot be included in the full path of the object. String objectName = "exampledir/exampleobject.txt"; //Create an OSSClient instance. OSS ossClient = new OSSClientBuilder().build(endpoint,  credentialsProvider); try { String content = "Hello OSS"; ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(content.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(); } } } }

Download files

The following code is used to download files from OSS through streaming download.

 import com.aliyun.oss.ClientException; import com.aliyun.oss.OSS; import com.aliyun.oss.OSSClientBuilder; import com.aliyun.oss.OSSException; import com.aliyun.oss.common.auth.CredentialsProviderFactory; import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider; import com.aliyun.oss.model.OSSObject; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; public class Demo { public static void main(String[] args) throws Exception { //Endpoint takes East China 1 (Hangzhou) as an example. Please fill in other regions according to the actual situation. String endpoint = " https://oss-cn-hangzhou.aliyuncs.com "; //Get access credentials from environment variables. Before running this code example, make sure that the environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET have been set. EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider(); //Fill in the bucket name, such as examplebucket. String bucketName = "examplebucket"; //Fill in the full path of the object, such as exampledir/exampleobject.txt. Bucket names cannot be included in the full path of the object. String objectName = "exampledir/exampleobject.txt"; //Create an OSSClient instance. OSS ossClient = new OSSClientBuilder().build(endpoint,  credentialsProvider); try { //Calling ossClient.getObject returns an OSSObject instance, which contains file content and file metadata. OSSObject ossObject = ossClient.getObject(bucketName, objectName); //Call ossObject.getObjectContent to get the file input stream, which can be read to get its content. InputStream content = ossObject.getObjectContent(); if (content !=  null) { BufferedReader reader = new BufferedReader(new InputStreamReader(content)); while (true) { String line = reader.readLine(); if (line == null) { break; } System.out.println("\n" + line); } //After the data reading is completed, the obtained stream must be closed, or the connection will leak, resulting in no connection available for the request, and the program cannot work normally. content.close(); } } 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 files

The following code is used to list the files in the bucket of the storage space. 100 files are listed by default.

 import com.aliyun.oss.ClientException; import com.aliyun.oss.OSS; import com.aliyun.oss.OSSClientBuilder; import com.aliyun.oss.OSSException; import com.aliyun.oss.common.auth.CredentialsProviderFactory; import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider; import com.aliyun.oss.model.OSSObjectSummary; import com.aliyun.oss.model.ObjectListing; public class Demo { public static void main(String[] args) throws Exception { //Endpoint takes East China 1 (Hangzhou) as an example. Please fill in other regions according to the actual situation. String endpoint = " https://oss-cn-hangzhou.aliyuncs.com "; //Get access credentials from environment variables. Before running this code example, make sure that the environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET have been set. EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider(); //Fill in the bucket name, such as examplebucket. String bucketName = "examplebucket"; //Create an OSSClient instance. OSS ossClient = new OSSClientBuilder().build(endpoint,  credentialsProvider); try { //OssClient.listObjects returns the ObjectListing instance, which contains the returned results of this listObject request. ObjectListing objectListing = ossClient.listObjects(bucketName); //ObjectListing.getObjectSummaries gets the description information of all files. for (OSSObjectSummary objectSummary : objectListing.getObjectSummaries()) { System.out.println(" - " + objectSummary.getKey() + "  " + "(size = " + objectSummary.getSize() + ")"); } } 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 File

The following code is used to delete the specified file.

 import com.aliyun.oss.ClientException; import com.aliyun.oss.OSS; import com.aliyun.oss.OSSClientBuilder; import com.aliyun.oss.OSSException; import com.aliyun.oss.common.auth.CredentialsProviderFactory; import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider; public class Demo { public static void main(String[] args) throws Exception { //Endpoint takes East China 1 (Hangzhou) as an example. Please fill in other regions according to the actual situation. String endpoint = " https://oss-cn-hangzhou.aliyuncs.com "; //Get access credentials from environment variables. Before running this code example, make sure that the environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET have been set. EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider(); //Fill in the bucket name, such as examplebucket. String bucketName = "examplebucket"; //Fill in the full path of the object, such as exampledir/exampleobject.txt. Bucket names cannot be included in the full path of the object. String objectName = "exampledir/exampleobject.txt"; //Create an OSSClient instance. OSS ossClient = new OSSClientBuilder().build(endpoint,  credentialsProvider); try { //Delete files. 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(); } } } }

Related Documents

• For the complete sample code involved in the Quick Start, see GitHub Example 。

• For the description of the API interface for creating storage space, see PutBucket 。

• For the description of the API interface for uploading files, see PutObject 。

• For the description of the API interface for downloading files, see GetObject 。

• Refer to GetBucket (ListObjects) 。

• For the description of the API interface for deleting files, see DeleteObject 。