Creating and Configuring an OBS Client (SDK for Java)

Scenarios

This section describes how to create and configure an OBS client. If you already have a client, skip this section and obtain the API details by referring to API Overview (SDK for Java).

Prerequisites

Ensure you have completed the following preparations:

1. Select a proper SDK version by referring to Before You Start (SDK for Java).
2. Prepare the service and development environments by referring to Preparations (SDK for Java).
3. Download and install the OBS SDK for Java by referring to SDK Download and Installation (SDK for Java).

Important Notes

• Make sure to configure the client at the time you create it. After the client is created, you will not be able to configure it.
• If you use a temporary AK/SK pair, you can call ObsClient.refresh("yourAccessKey", "yourSecretKey", "yourSecurityToken") to refresh to keep the pair valid, without the need to create a new ObsClient instance.
• You are advised to create an ObsClient instance at the initialization and use it for the whole project. Creating multiple clients affects high-concurrency performance.
• ObsClient is thread-safe and can be used in concurrency scenarios.
• If a client is closed by calling ObsClient.close, it cannot be used again. To ensure the whole project uses only one client, you are advised not to proactively close the client.

Overview

Figure 1 Creating and configuring a client

You can select a client class, a method of obtaining access credentials, and other parameters by referring to Figure 1.

Code Examples

• Using the client class that does not transparently transmit access credentials to directly configure access credentials and configuring the endpoint
  • Using permanent access keys (AKs/SKs)

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    // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak = System.getenv("ACCESS_KEY_ID"); String sk = System.getenv("SECRET_ACCESS_KEY_ID"); // Create an ObsClient instance. ObsClient obsClient = new ObsClient(ak, sk, endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

  • Using temporary access credentials (AKs/SKs and security tokens)

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    // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak = System.getenv("ACCESS_KEY_ID"); String sk = System.getenv("SECRET_ACCESS_KEY_ID"); String securityToken = System.getenv("SECRET_TOKEN"); // Create an ObsClient instance. ObsClient obsClient = new ObsClient(ak, sk, securityToken, endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

  • BasicObsCredentialsProvider

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    // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak = System.getenv("ACCESS_KEY_ID"); String sk = System.getenv("SECRET_ACCESS_KEY_ID"); // Create an ObsClient instance. ObsClient obsClient = new ObsClient(new BasicObsCredentialsProvider(ak, sk), endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

• Using the SecretFlexibleObsClient client class that transparently transmits access credentials

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  // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Create an instance of the ObsConfiguration class. ObsConfiguration config = new ObsConfiguration(); config.setEndPoint(endPoint); // Create an instance of SecretFlexibleObsClient. SecretFlexibleObsClient obsClient = new SecretFlexibleObsClient(config); // Use the instance of SecretFlexibleObsClient to access OBS. // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak1 = System.getenv("ACCESS_KEY_ID"); String sk1 = System.getenv("SECRET_ACCESS_KEY_ID"); obsClient.listBuckets(ak1, sk1); String ak2 = System.getenv("ACCESS_KEY_ID"); String sk2 = System.getenv("SECRET_ACCESS_KEY_ID"); obsClient.listBuckets(ak2, sk2); // Close the instance. obsClient.close();

• Using EnvironmentVariableObsCredentialsProvider to obtain access credentials from environment variables
  In this method, you need to define OBS_ACCESS_KEY_ID and OBS_SECRET_ACCESS_KEY in the environment variables to represent the permanent AK and SK respectively.

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  // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Create an ObsClient instance. ObsClient obsClient = new ObsClient(new EnvironmentVariableObsCredentialsProvider(), endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

• Using EcsObsCredentialsProvider to obtain access credentials from an agency in the ECS scenarios

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  // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Create an ObsClient instance. ObsClient obsClient = new ObsClient(new EcsObsCredentialsProvider(), endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

• Using OBSCredentialsProviderChain to obtain access credentials from a chain

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  // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Create an ObsClient instance. ObsClient obsClient = new ObsClient(new OBSCredentialsProviderChain(), endPoint); // Use the instance to access OBS. // Close the instance. obsClient.close();

• Using ObsConfiguration to configure parameters for the client
  • KeyManagerFactory: By configuring KeyManagerFactory, you can save a certificate on your local PC and check whether the certificate returned by the server is correct.

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    // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak = System.getenv("ACCESS_KEY_ID"); String sk = System.getenv("SECRET_ACCESS_KEY_ID"); String jksPassword = "you-jks-password"; String jksPath = "/path/to/your/keystore/file"; KeyStore ks = KeyStore.getInstance("JKS"); char[] passArray = jksPassword.toCharArray(); FileInputStream inputStream = new FileInputStream(jksPath); ks.load(inputStream, passArray); KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm()); kmf.init(ks, passArray); String trustJKSPassword = "you-trustJKS-password"; String trustJKSPath = "/path/to/your/trustKeyStore/file"; KeyStore trustKeyStore = KeyStore.getInstance("JKS"); char[] trustPassArray = trustJKSPassword.toCharArray(); FileInputStream trustInputStream = new FileInputStream(trustJKSPath); trustKeyStore.load(trustInputStream, trustPassArray); TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm()); tmf.init(trustKeyStore); ObsConfiguration config = new ObsConfiguration(); config.setEndPoint(endPoint); config.setKeyManagerFactory(kmf); config.setTrustManagerFactory(tmf); ObsClient obsClient = new ObsClient(ak, sk, config);

    

    The local certificate must be stored as a .jks file. You can run the following command to call the Java keytool to convert a .cer certificate into a .jks one:

    keytool -import -file your-cer-file.cer -keystore your-keystore-file.jks

  • HTTP proxy: After the HTTP proxy is configured, the SDK uses the proxy to access the server.

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    // Replace the following region with the one in use. EU-Dublin is used here as an example. String endPoint = "https://obs.eu-west-101.myhuaweicloud.com"; // Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID. // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html. String ak = System.getenv("ACCESS_KEY_ID"); String sk = System.getenv("SECRET_ACCESS_KEY_ID"); String proxyUrl = "proxy.com"; int proxyPort = 8080; String proxyUser = "userName"; String proxyPassword = "password"; ObsConfiguration config = new ObsConfiguration(); config.setEndPoint(endPoint); config.setHttpProxy(proxyUrl, proxyPort, proxyUser, proxyPassword); ObsClient obsClient = new ObsClient(ak, sk,config);

Configuring a User-Defined Domain Name to Access OBS

To learn how to configure a user-defined domain name, see Configuring a User-Defined Domain Name.

// Specify the user-defined domain name that has been configured on the console.
String endPoint = "http://your-domain";
// Hard-coded or plaintext access keys (AK/SK) are risky. For security purposes, encrypt your access keys and store them in the configuration file or environment variables. In this example, access keys are stored in the environment variables for identity authentication. Before running the code in this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");

// Create an instance of the ObsConfiguration class.
ObsConfiguration config = new ObsConfiguration();
config.setEndPoint(endPoint);
config.setCname(true);

// Create an ObsClient instance.
ObsClient obsClient = new ObsClient(ak, sk, config);

// Create an instance of ObsClient using Provider.
// ObsClient obsClient = new ObsClient(new EnvironmentVariableObsCredentialsProvider(), config);
// ObsClient obsClient = new ObsClient(new EcsObsCredentialsProvider(), config);

// Use the instance to access OBS.

// Close the instance.
obsClient.close();

ObsConfiguration Parameters

• If the network bandwidth is sufficient, you can tune the socketWriteBufferSize, sockeReadBufferSize, readBufferSize, and writeBufferSize parameters to improve upload and download performance.
• If the network condition is poor, you are advised to increase the values of connectionTimeout and socketTimeout.