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Huawei Cloud Java Software Development Kit (Java SDK)

The Huawei Cloud Java SDK allows you to easily work with Huawei Cloud services such as Elastic Compute Service (ECS) and Virtual Private Cloud (VPC) without the need to handle API related tasks.

This document introduces how to obtain and use Huawei Cloud Java SDK.

Requirements

  • To use Huawei Cloud Java SDK, you must have Huawei Cloud account as well as the Access Key (AK) and Secret key (SK) of the Huawei Cloud account. You can create an Access Key in the Huawei Cloud console. For more information, see My Credentials.

  • To use Huawei Cloud Java SDK to access the APIs of specific service, please make sure you do have activated the service in Huawei Cloud console if needed.

  • Huawei Cloud Java SDK requires Java JDK 1.8 or later.

Install Java SDK

It is recommended to use Maven to declare dependencies to use our Java SDK.

At first, you need to download and install Maven, and then declare dependencies in the pom.xml file in your Java project.

Please choose a specific version number when specifying dependencies, otherwise it may cause unforeseen issues at build time.

You can get the SDK version information through SDK center or Maven central repository.

Individual Services

You can add depenencies for the specific services only. Take using ECS and VPC SDK for example, you need to import huaweicloud-sdk-ecs and huaweicloud-sdk-vpc libraries:

<dependency>
    <groupId>com.huaweicloud.sdk</groupId>
    <artifactId>huaweicloud-sdk-ecs</artifactId>
    <version>${version}</version>
</dependency>
<dependency>
    <groupId>com.huaweicloud.sdk</groupId>
    <artifactId>huaweicloud-sdk-vpc</artifactId>
    <version>${version}</version>
</dependency>

Whole SDK

You can add only one dependency library to import all supported services.(3.0.40-rc or later):

<dependency>
    <groupId>com.huaweicloud.sdk</groupId>
    <artifactId>huaweicloud-sdk-all</artifactId>
    <version>${version}</version>
</dependency>

Bundle SDK

If a third-party library conflict occurs, you can import a single bundle library(3.0.40-rc or later). The bundle library contains all supported services and dependent JARs with third-party libraries relocated to different namespaces:

<dependency>
    <groupId>com.huaweicloud.sdk</groupId>
    <artifactId>huaweicloud-sdk-bundle</artifactId>
    <version>${version}</version>
</dependency>

Common conflicts, such as Jackson and okhttp3 version conflicts.

Note: The bundle library already includes the core package and cloud service package. Do not import the core library and service library separately. According to the Maven dependency parsing sequence, the bundle library may not take effect.

The following is an incorrect example:

com.huaweicloud.sdk huaweicloud-sdk-core ${version} com.huaweicloud.sdk huaweicloud-sdk-ecs ${version} com.huaweicloud.sdk huaweicloud-sdk-bundle ${version}

Code Example

  • The following example shows how to query a list of VPCs synchronously in a specific region, you need to substitute your real {Service}Client for VpcClient in actual use.
  • Hard-coding ak and sk for authentication into the code has a great security risk. It is recommended to store the ciphertext in the profile or environment variables and decrypt it when used to ensure security.
  • In this example, ak and sk are stored in environment variables. Please configure the environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK before running this example.

Simplified Demo

package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.vpc.v2.VpcClient;
import com.huaweicloud.sdk.vpc.v2.model.ListVpcsRequest;
import com.huaweicloud.sdk.vpc.v2.model.ListVpcsResponse;
import com.huaweicloud.sdk.vpc.v2.region.VpcRegion;

public class Application {
    public static void main(String[] args) {
        // Configure authentication
        // Authentication can be configured through environment variables and other methods. Please refer to Chapter 2.4 Authentication Management
        ICredential auth = new BasicCredentials()
                .withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
                .withSk(System.getenv("HUAWEICLOUD_SDK_SK"));

        // Create a service client
        VpcClient client = VpcClient.newBuilder()
                .withCredential(auth)
                .withRegion(VpcRegion.valueOf("cn-north-4"))
                .build();

        // Send the request and get the response
        ListVpcsRequest request = new ListVpcsRequest();
        try {
            ListVpcsResponse response = client.listVpcs(request);
            System.out.println(response.toString());
        } catch (ConnectionException | RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

Detailed Demo

package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.HttpListener;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.SigningAlgorithm;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.core.http.HttpConfig;
import com.huaweicloud.sdk.vpc.v2.VpcClient;
import com.huaweicloud.sdk.vpc.v2.model.ListVpcsRequest;
import com.huaweicloud.sdk.vpc.v2.model.ListVpcsResponse;
import com.huaweicloud.sdk.vpc.v2.region.VpcRegion;

import java.util.stream.Collectors;

public class Application {
    public static void main(String[] args) {
        // Configure authentication
        ICredential auth = new BasicCredentials()
                // Authentication can be configured through environment variables and other methods. Please refer to Chapter 2.4 Authentication Management
                .withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
                .withSk(System.getenv("HUAWEICLOUD_SDK_SK"))
                // If projectId is not filled in, the SDK will automatically call the IAM service to query the project id corresponding to the region.
                .withProjectId("{your projectId string}")
                // Configure the SDK built-in IAM service endpoint, default is https://iam.myhuaweicloud.com
                .withIamEndpoint("https://iam.cn-north-4.myhuaweicloud.com");

        // Use default configuration
        HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig();
        // Configure whether to ignore the SSL certificate verification, default is false
        httpConfig.withIgnoreSSLVerification(true);
        // Configure connection time out as needed, default is 60 seconds (v3.1.94 and earlier versions)
        httpConfig.withTimeout(60);
        // Configure connection time out as needed, default is 60 seconds (since v3.1.95, withConnectionTimeout is preferred)
        httpConfig.withConnectionTimeout(60);
        // Configure read time out as needed, default is 120 seconds
        httpConfig.withReadTimeout(120);
        // Configure proxy as needed, the default protocol is `http`
        // Replace the proxy host and port in the example according to the actual situation
        httpConfig.withProxyHost("proxy.huaweicloud.com")
                .withProxyPort(8080)
            	// Configure the username and password if the proxy requires authentication
                .withProxyUsername(System.getenv("PROXY_USERNAME"))
                .withProxyPassword(System.getenv("PROXY_PASSWORD"));
        // Configure SSLSocketFactory and TrustManager, user implementation is required
        httpConfig.withSSLSocketFactory(sslSocketFactory)
                .withX509TrustManager(trustManager);
        // JDK8u302+ is required when using HMAC_SM3, default is HMAC_SHA256
        httpConfig.withSigningAlgorithm(SigningAlgorithm.HMAC_SM3);
        // Print the original request after registering the listener, do not use it in a production environment
        HttpListener requestListener = HttpListener.forRequestListener(listener ->
                System.out.printf("> Request %s %s\n> Headers:\n%s\n> Body: %s\n",
                        listener.httpMethod(),
                        listener.uri(),
                        listener.headers().entrySet().stream()
                                .flatMap(entry -> entry.getValue().stream().map(
                                        value -> "\t" + entry.getKey() + ": " + value))
                                .collect(Collectors.joining("\n")),
                        listener.body().orElse("")));
        httpConfig.addHttpListener(requestListener);
        // Print the original response after registering the listener, do not use it in a production environment
        HttpListener responseListener = HttpListener.forResponseListener(listener ->
                System.out.printf("< Response %s %s %s\n< Headers:\n%s\n< Body: %s\n",
                        listener.httpMethod(),
                        listener.uri(),
                        listener.statusCode(),
                        listener.headers().entrySet().stream()
                                .flatMap(entry -> entry.getValue().stream().map(
                                        value -> "\t" + entry.getKey() + ": " + value))
                                .collect(Collectors.joining("\n")),
                        listener.body().orElse("")));
        httpConfig.addHttpListener(responseListener);

        // Create a service client
        VpcClient client = VpcClient.newBuilder()
                // Configure authentication
                .withCredential(auth)
                // Configure region, it will throw a IllegalArgumentException if the region does not exist
                .withRegion(VpcRegion.valueOf("cn-north-4"))
                // Configure HTTP
                .withHttpConfig(httpConfig)
                .build();

        // Create a request
        ListVpcsRequest request = new ListVpcsRequest();
        // Configure the number of records on each page
        request.setLimit(1);
        try {
            // Send the request and get the response
            ListVpcsResponse response = client.listVpcs(request);
            System.out.println(response.toString());
        } catch (ConnectionException | RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

Online Debugging

API Explorer provides api retrieval, SDK samples and online debugging, supports full fast retrieval, visual debugging, help document viewing, and online consultation.

Changelog

Detailed changes for each released version are documented in the CHANGELOG.md.

User Manual 🔝

1. Client Configuration 🔝

1.1 Default Configuration 🔝

import com.huaweicloud.sdk.core.http.HttpConfig;

// Use default configuration
HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig();

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

1.2 Network Proxy 🔝

Java SDK only supports HTTP proxy configuration currently.

// Use network proxy if needed, the default protocol is `http`
HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig()
    // Replace the proxy host and port in the example according to the actual situation
    .withProxyHost("proxy.huaweicloud.com")
    .withProxyPort(8080)
    // Configure the username and password if the proxy requires authentication
    // In this example, username and password are stored in environment variables. Please configure the environment variables PROXY_USERNAME and PROXY_PASSWORD before running this example.
    .withProxyUsername(System.getenv("PROXY_USERNAME"))
    .withProxyPassword(System.getenv("PROXY_PASSWORD"));

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

1.3 Timeout Configuration 🔝

HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig()
// The default connection time out is 60 seconds, change it if needed (v3.1.94 and earlier versions)
.withTimeout(60)
// The default connection time out is 60 seconds, change it if needed (since v3.1.95, withConnectionTimeout is preferred)
.withConnectionTimeout(60)
// The default read time out is 120 seconds, change it if needed
.withReadTimeout(120);

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

1.4 SSL Certification 🔝

Skip SSL certification:

// Skip SSL certification checking while using https protocol if needed
HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig().withIgnoreSSLVerification(true);

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

Customized configuration:

// Configure SSLSocketFactory, TrustManager and HostnameVerifier, user implementation is required.
HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig()
    .withSSLSocketFactory(sslSocketFactory)
    .withX509TrustManager(trustManager)
    .withHostnameVerifier(hostnameVerifier);

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

1.5 Signing Algorithm 🔝

import com.huaweicloud.sdk.core.auth.SigningAlgorithm;

// JDK8u302+ is required when using HMAC_SM3, default signing algorithm is HMAC_SHA256
HttpConfig.getDefaultHttpConfig().withSigningAlgorithm(SigningAlgorithm.HMAC_SM3);

VpcClient client = VpcClient.newBuilder()
        .withHttpConfig(httpConfig)
        .build();

2. Credentials Configuration 🔝

There are two types of Huawei Cloud services, regional services and global services.

Global services contain BSS, DevStar, EPS, IAM, OSM, RMS, TMS.

For regional services' authentication, projectId is required to initialize BasicCredentials.

For global services' authentication, domainId is required to initialize GlobalCredentials.

The following authentications are supported:

  • permanent AK&SK
  • temporary AK&SK + SecurityToken
  • IdpId&IdTokenFile

Parameter description:

  • ak is the access key ID for your account.
  • sk is the secret access key for your account.
  • projectId is the ID of your project depending on the region you want to operate.
  • domainId is the account ID of Huawei Cloud.
  • securityToken is the security token when using temporary AK/SK.

2.1 Use Permanent AK&SK 🔝

Parameter description:

  • ak is the access key ID for your account.
  • sk is the secret access key for your account.
  • projectId is the ID of your project depending on the region you want to operate.
  • domainId is the account ID of Huawei Cloud.
// Regional Services
String ak = System.getenv("HUAWEICLOUD_SDK_AK");
String sk = System.getenv("HUAWEICLOUD_SDK_SK");
String projectId = "{your projectId string}";

BasicCredentials basicCredentials = new BasicCredentials()
    .withAk(ak)
    .withSk(sk)
    .withProjectId(projectId)

// Global Services
String ak = System.getenv("HUAWEICLOUD_SDK_AK");
String sk = System.getenv("HUAWEICLOUD_SDK_SK");
String domainId = "{your domainId string}";

GlobalCredentials globalCredentials = new GlobalCredentials()
    .withAk(ak)
    .withSk(sk)
    .withDomainId(domainId);

Notice:

  • projectId/domainId supports automatic acquisition in version 3.0.26-beta or later, if you want to use this feature, you need to provide the ak and sk of your account and the id of the region, and then build your client instance with method withRegion(), detailed example could refer to 3.2 Initialize the client with specified Region .

2.2 Use Temporary AK&SK 🔝

A temporary access key and securityToken are issued by the system to IAM users, and can be valid for 15 minutes to 24 hours. After the validity period expires, you need to obtain them again. It's required to obtain temporary AK&SK and security token first, which could be obtained through permanent AK&SK or through an agency.

Parameter description:

  • ak is the access key ID for your account.
  • sk is the secret access key for your account.
  • projectId is the ID of your project depending on the region you want to operate.
  • domainId is the account ID of Huawei Cloud.
  • securityToken is the security token when using temporary AK/SK.
// Regional services
String ak = System.getenv("HUAWEICLOUD_SDK_AK");
String sk = System.getenv("HUAWEICLOUD_SDK_SK");
String securityToken = System.getenv("HUAWEICLOUD_SDK_SECURITY_TOKEN");
String projectId = "{your projectId string}";

BasicCredentials basicCredentials = new BasicCredentials()
    .withAk(ak)
    .withSk(sk)
    .withSecurityToken(securityToken)
    .withProjectId(projectId)

// Global services
String ak = System.getenv("HUAWEICLOUD_SDK_AK");
String sk = System.getenv("HUAWEICLOUD_SDK_SK");
String securityToken = System.getenv("HUAWEICLOUD_SDK_SECURITY_TOKEN");
String domainId = "{your domainId string}";

GlobalCredentials globalCredentials = new GlobalCredentials()
    .withAk(ak)
    .withSk(sk)
    .withSecurityToken(securityToken)
    .withDomainId(domainId);

In the following two cases, the credential information will be obtained from the metadata of the instance:

  1. BasicCredentials or GlobalCredentials were not manually specified when creating the client.
  2. AK/SK was not specified when creating BasicCredentials or GlobalCredentials.

Refer to the Obtaining Metadata for more information.

// Regional services
BasicCredentials credentials = new BasicCredentials().withProjectId(projectId);

// Global services
GlobalCredentials credentials = new GlobalCredentials().withDomainId(domainId);

2.3 Use IdpId&IdTokenFile 🔝

Obtain a federated identity authentication token using an OpenID Connect ID token, refer to the Obtaining a Token with an OpenID Connect ID Token

Parameter description:

  • IdpId Identity provider ID.
  • IdTokenFile Id token file path. Id token is constructed by the enterprise IdP to carry the identity information of federated users.
  • projectId is the ID of your project depending on your region which you want to operate.
  • domainId is the account ID of Huawei Cloud.
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.auth.GlobalCredentials;

// Regional service
BasicCredentials basicCredentials = new BasicCredentials()
    .withIdpId(idpId)
    .withIdTokenFile(idTokenFile)
    .withProjectId(projectId)

// Global service
GlobalCredentials globalCredentials = new GlobalCredentials()
    .withIdpId(idpId)
    .withIdTokenFile(idTokenFile)
    .withDomainId(domainId);

2.4 Authentication Management 🔝

Getting Authentication from providers is supported since v3.0.97

Regional services use XxxCredentialProvider.getBasicCredentialXxxProvider()

Global services use XxxCredentialProvider.getGlobalCredentialXxxProvider()

2.4.1 Environment Variables 🔝

AK/SK Auth

Environment Variables Notice
HUAWEICLOUD_SDK_AK Required, AccessKey
HUAWEICLOUD_SDK_SK Required, SecretKey
HUAWEICLOUD_SDK_SECURITY_TOKEN Optional, this parameter needs to be specified when using temporary ak/sk
HUAWEICLOUD_SDK_PROJECT_ID Optional, used for regional services, required in multi-ProjectId scenarios
HUAWEICLOUD_SDK_DOMAIN_ID Optional, used for global services

Configure environment variables:

// Linux
export HUAWEICLOUD_SDK_AK=YOUR_AK
export HUAWEICLOUD_SDK_SK=YOUR_SK

// Windows
set HUAWEICLOUD_SDK_AK=YOUR_AK
set HUAWEICLOUD_SDK_SK=YOUR_SK

Get the credentials from configured environment variables:

import com.huaweicloud.sdk.core.auth.EnvCredentialProvider;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
EnvCredentialProvider basicProvider = EnvCredentialProvider.getBasicCredentialEnvProvider();
ICredential basicCred = basicProvider.getCredentials();

// global
EnvCredentialProvider globalProvider = EnvCredentialProvider.getGlobalCredentialEnvProvider();
ICredential globalCred = globalProvider.getCredentials();

IdpId/IdTokenFile Auth

Environment Variables Notice
HUAWEICLOUD_SDK_IDP_ID Required, identity provider Id
HUAWEICLOUD_SDK_ID_TOKEN_FILE Required, id token file path
HUAWEICLOUD_SDK_PROJECT_ID For basic credentials, this parameter is required
HUAWEICLOUD_SDK_DOMAIN_ID For global credentials, this parameter is required

Configure environment variables:

// Linux
export HUAWEICLOUD_SDK_IDP_ID=YOUR_IDP_ID
export HUAWEICLOUD_SDK_ID_TOKEN_FILE=/some_path/your_token_file
export HUAWEICLOUD_SDK_PROJECT_ID=YOUR_PROJECT_ID // For basic credentials, this parameter is required
export HUAWEICLOUD_SDK_DOMAIN_ID=YOUR_DOMAIN_ID // For global credentials, this parameter is required

// Windows
set HUAWEICLOUD_SDK_IDP_ID=YOUR_IDP_ID
set HUAWEICLOUD_SDK_ID_TOKEN_FILE=/some_path/your_token_file
set HUAWEICLOUD_SDK_PROJECT_ID=YOUR_PROJECT_ID // For basic credentials, this parameter is required
set HUAWEICLOUD_SDK_DOMAIN_ID=YOUR_DOMAIN_ID // For global credentials, this parameter is required

Get the credentials from configured environment variables:

import com.huaweicloud.sdk.core.auth.EnvCredentialProvider;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
EnvCredentialProvider basicProvider = EnvCredentialProvider.getBasicCredentialEnvProvider();
ICredential basicCred = basicProvider.getCredentials();

// global
EnvCredentialProvider globalProvider = EnvCredentialProvider.getGlobalCredentialEnvProvider();
ICredential globalCred = globalProvider.getCredentials();
2.4.2 Profile 🔝

The profile will be read from the user's home directory by default, linux~/.huaweicloud/credentials,windowsC:\Users\USER_NAME\.huaweicloud\credentials, the path to the profile can be modified by configuring the environment variable HUAWEICLOUD_SDK_CREDENTIALS_FILE

AK/SK Auth

Configuration Parameters Notice
ak Required, AccessKey
sk Required, SecretKey
security_token Optional, this parameter needs to be specified when using temporary ak/sk
project_id Optional, used for regional services, required in multi-ProjectId scenarios
domain_id Optional, used for global services
iam_endpoint optional, endpoint for authentication, default is https://iam.myhuaweicloud.com

The content of the profile is as follows:

[basic]
ak = your_ak
sk = your_sk

[global]
ak = your_ak
sk = your_sk

Get the credentials from profile:

import com.huaweicloud.sdk.core.auth.ProfileCredentialProvider;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
ProfileCredentialProvider basicProvider = ProfileCredentialProvider.getBasicCredentialProfileProvider();
ICredential basicCred = basicProvider.getCredentials();

// global
ProfileCredentialProvider globalProvider = ProfileCredentialProvider.getGlobalCredentialProfileProvider();
ICredential globalCred = globalProvider.getCredentials();

IdpId/IdTokenFile Auth

Configuration Parameters Notice
idp_id Required, identity provider Id
id_token_file Required, id token file path
project_id For basic credentials, this parameter is required
domain_id For global credentials, this parameter is required
iam_endpoint optional, endpoint for authentication, default is https://iam.myhuaweicloud.com

The content of the profile is as follows:

[basic]
idp_id = your_idp_id
id_token_file = /some_path/your_token_file
project_id = your_project_id

[global]
idp_id = your_idp_id
id_token_file = /some_path/your_token_file
domainId = your_domain_id

Get the credentials from profile:

import com.huaweicloud.sdk.core.auth.ProfileCredentialProvider;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
ProfileCredentialProvider basicProvider = ProfileCredentialProvider.getBasicCredentialProfileProvider();
ICredential basicCred = basicProvider.getCredentials();

// global
ProfileCredentialProvider globalProvider = ProfileCredentialProvider.getGlobalCredentialProfileProvider();
ICredential globalCred = globalProvider.getCredentials();
2.4.3 Metadata 🔝

Get temporary AK/SK and securitytoken from instance's metadata. Refer to the Obtaining Metadata for more information.

Manually obtain authentication from instance metadata:

import com.huaweicloud.sdk.core.auth.MetadataCredentialProvider;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
MetadataCredentialProvider basicProvider = MetadataCredentialProvider.getBasicCredentialMetadataProvider();
ICredential basicCred = basicProvider.getCredentials();

// global
MetadataCredentialProvider globalProvider = MetadataCredentialProvider.getGlobalCredentialMetadataProvider();
ICredential globalCred = globalProvider.getCredentials();
2.4.4 Provider Chain 🔝

When creating a service client without credentials, try to load authentication in the order Environment Variables -> Profile -> Metadata

Get authentication from provider chain:

import com.huaweicloud.sdk.core.auth.CredentialProviderChain;
import com.huaweicloud.sdk.core.auth.ICredential;

// basic
CredentialProviderChain basicChain = CredentialProviderChain.getBasicCredentialProviderChain();
ICredential basicCred = basicChain.getCredentials();

// global
CredentialProviderChain globalChain = CredentialProviderChain.getGlobalCredentialProviderChain();
ICredential globalCred = globalChain.getCredentials();

Custom credentials provider chain is supported:

import com.huaweicloud.sdk.core.auth.CredentialProviderChain;
import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.ICredentialProvider;
import com.huaweicloud.sdk.core.auth.MetadataCredentialProvider;
import com.huaweicloud.sdk.core.auth.ProfileCredentialProvider;

ICredentialProvider[] providers = new ICredentialProvider[]{
        MetadataCredentialProvider.getBasicCredentialMetadataProvider(),
        ProfileCredentialProvider.getBasicCredentialProfileProvider()
};
CredentialProviderChain chain = new CredentialProviderChain(providers);
ICredential cred = chain.getCredentials();

3. Client Initialization 🔝

There are two ways to initialize the {Service}Client, you could choose one you preferred.

3.1 Initialize the {Service}Client with specified Endpoint 🔝

// Specify the endpoint, take the endpoint of VPC service in region of cn-north-4 for example
String endpoint = "https://vpc.cn-north-4.myhuaweicloud.com";

// Initialize the credentials, you should provide projectId or domainId in this way, take initializing BasicCredentials for example
BasicCredentials basicCredentials = new BasicCredentials()
    .withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
    .withSk(System.getenv("HUAWEICLOUD_SDK_SK"))
    .withProjectId("{your projectId string}");

// Initialize specified service client instance, take initializing the regional service VPC's VpcClient for example
VpcClient vpcClient = VpcClient.newBuilder()
    .withHttpConfig(config)
    .withCredential(basicCredentials)
    .withEndpoint(endpoint)
    .build();

where:

  • endpoint varies by services and regions, see Regions and Endpoints to obtain correct endpoint.

  • When you meet some trouble in getting projectId using the specified region way, you could use this way instead.

3.2 Initialize the {Service}Client with specified Region (Recommended) 🔝

// dependency for region module
import com.huaweicloud.sdk.iam.v3.region.IamRegion;

// Initialize the credentials, projectId or domainId could be unassigned in this situation, take initializing GlobalCredentials for example
GlobalCredentials globalCredentials = new GlobalCredentials()
    .withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
    .withSk(System.getenv("HUAWEICLOUD_SDK_SK"));

// Initialize specified service client instance, take initializing the global service IAM's IamClient for example
IamClient iamClient = IamClient.newBuilder()
    .withHttpConfig(config)
    .withCredential(globalCredentials)
    .withRegion(IamRegion.CN_NORTH_4)
    .build();

Notice:

  • If you use region to initialize {Service}Client, projectId/domainId supports automatic acquisition, you don't need to configure it when initializing Credentials.

  • Multiple ProjectId situation is not supported.

  • You can query the supported regions through Regions and Endpoints. You may get exception such as Unsupported regionId if you specify an unsupported region.

Comparison of the two ways:

Initialization Advantages Disadvantage
Specified Endpoint The API can be invoked successfully once it has been published in the environment. You need to prepare projectId and endpoint yourself.
Specified Region No need for projectId and endpoint, it supports automatic acquisition if you configure it in the right way. The supported services and regions are limited.

3.3 Custom Configuration 🔝

Notice: Supported since v3.0.93

3.3.1 IAM endpoint configuration 🔝

Automatically acquiring projectId/domainId will invoke the KeystoneListProjects /KeystoneListAuthDomains interface of IAM service. The default iam enpoint is https://iam.myhuaweicloud.com, European station users need to specify the endpoint as https://iam.eu-west-101.myhuaweicloud.eu, you can modify the endpoint in the following two ways:

3.3.1.1 Global scope 🔝

This configuration takes effect globally, specified by environment variable HUAWEICLOUD_SDK_IAM_ENDPOINT

//linux
export HUAWEICLOUD_SDK_IAM_ENDPOINT=https://iam.cn-north-4.myhuaweicloud.com

//windows
set HUAWEICLOUD_SDK_IAM_ENDPOINT=https://iam.cn-north-4.myhuaweicloud.com
3.3.1.2 Credentials scope 🔝

This configuration is only valid for a credential, and it will override the global configuration

import com.huaweicloud.sdk.core.auth.BasicCredentials;

String iamEndpoint = "https://iam.cn-north-4.myhuaweicloud.com";
BasicCredentials credentials = new BasicCredentials()
	.withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
    .withSk(System.getenv("HUAWEICLOUD_SDK_SK"))
    .withIamEndpoint(iamEndpoint);
3.3.2 Region configuration 🔝
3.3.2.1 Code 🔝
import com.huaweicloud.sdk.core.region.Region;
import com.huaweicloud.sdk.ecs.v2.EcsClient;

// Create a region with custom region id and endpoint
Region region = new Region("cn-north-9", "https://ecs.cn-north-9.myhuaweicloud.com");

EcsClient client = EcsClient.newBuilder()
    .withCredential(auth)
    .withRegion(region)
    .build();
3.3.2.2 Environment variable 🔝

Specified by environment variable, the format is HUAWEICLOUD_SDK_REGION_{SERVICE_NAME}_{REGION_ID}={endpoint}

Notice: the name of environment variable is UPPER-CASE, replacing hyphens with underscores.

// Take ECS and IoTDA services as examples

// linux
export HUAWEICLOUD_SDK_REGION_ECS_CN_NORTH_9=https://ecs.cn-north-9.myhuaweicloud.com
export HUAWEICLOUD_SDK_REGION_IOTDA_AP_SOUTHEAST_1=https://iotda.ap-southwest-1.myhuaweicloud.com

// windows
set HUAWEICLOUD_SDK_REGION_ECS_CN_NORTH_9=https://ecs.cn-north-9.myhuaweicloud.com
set HUAWEICLOUD_SDK_REGION_IOTDA_AP_SOUTHEAST_1=https://iotda.ap-southwest-1.myhuaweicloud.com

A region corresponding to multiple endpoints is supported since v3.1.60, if the main endpoint cannot be connected, it will automatically switch to the backup endpoint.

The format is HUAWEICLOUD_SDK_REGION_{SERVICE_NAME}_{REGION_ID}={endpoint1},{endpoint2}, separate multiple endpoints with commas, such as HUAWEICLOUD_SDK_REGION_ECS_CN_NORTH_9=https://ecs.cn-north-9.myhuaweicloud.com,https://ecs.cn-north-9.myhuaweicloud.cn

3.3.2.3 Profile 🔝

The profile will be read from the user's home directory by default, linux~/.huaweicloud/regions.yaml,windowsC:\Users\USER_NAME\.huaweicloud\regions.yaml,the default file may not exist, but if the file exists and the content format is incorrect, an exception will be thrown for parsing errors.

The path to the profile can be modified by configuring the environment variable HUAWEICLOUD_SDK_REGIONS_FILE, like HUAWEICLOUD_SDK_REGIONS_FILE=/tmp/my_regions.yml

The file content format is as follows:

# Service name is case-insensitive
ECS:
  - id: 'cn-north-1'
    endpoint: 'https://ecs.cn-north-1.myhuaweicloud.com'
  - id: 'cn-north-9'
    endpoint: 'https://ecs.cn-north-9.myhuaweicloud.com'
IoTDA:
  - id: 'ap-southwest-1'
    endpoint: 'https://iotda.ap-southwest-1.myhuaweicloud.com'

A region corresponding to multiple endpoints is supported since v3.1.62, if the main endpoint cannot be connected, it will automatically switch to the backup endpoint.

ECS:
  - id: 'cn-north-1'
    endpoints:
      - 'https://ecs.cn-north-1.myhuaweicloud.com'
      - 'https://ecs.cn-north-1.myhuaweicloud.cn'
3.3.2.4 Region supply chain 🔝

The default lookup order is environment variables -> profile -> region defined in SDK of method Region.valueOf(regionId), if the region is not found in the above ways, an exception IllegalArgumentException will be thrown.

import com.huaweicloud.sdk.core.region.Region;
import com.huaweicloud.sdk.ecs.v2.region.EcsRegion;

Region region1 = EcsRegion.valueOf("cn-north-1");
Region region2 = EcsRegion.valueOf("cn-north-9");

4. Send Requests and Handle Responses 🔝

// send a request and print response, take interface of ListVpcs for example
ListVpcRequest request = new ListVpcsRequest().withLimit(1);

ListVpcsResponse response = client.listVpcs(request); 
logger.info(response.toString());

4.1 Exceptions 🔝

Level 1 Notice Level 2 Notice
ConnectionException Connection error HostUnreachableException host is not reachable
SslHandShakeException SSL certification error
ConnectionTimeoutException connect timed out
RequestTimeoutException Request timeout CallTimeoutException timeout for single request
RetryOutageException no response after retrying
ServiceResponseException service response error ServerResponseException server inner error, http status code: [500,]
ClientRequestException invalid request, http status code: [400? 500)
try {
    ListVpcRequest request = new ListVpcsRequest().withLimit(1);

    ListVpcsResponse response = client.listVpcs(request); 
    logger.info(response.toString());
} catch(ServiceResponseException e) {
    logger.error("HttpStatusCode: " + e.getHttpStatusCode());
    logger.error("RequestId: " + e.getRequestId());
    logger.error("ErrorCode: " + e.getErrorCode());
    logger.error("ErrorMsg: " + e.getErrorMsg());
}

5. Use Asynchronous Client 🔝

// Initialize asynchronous client, take VpcAsyncClient for example
VpcAsyncClient vpcAsyncClient = VpcAsyncClient.newBuilder()
    .withHttpConfig(config)
    .withCredential(basicCredentials)
    .withEndpoint(endpoint)
    .build();

// send asynchronous request
CompletableFuture<ListVpcsResponse> future = vpcAsyncClient.listVpcsAsync(new ListVpcsRequest().withLimit(1));
// get asynchronous response
ListVpcsResponse response = future.get();
logger.info(response.toString());

6. Troubleshooting 🔝

SDK supports Access log and Debug log which could be configured manually.

6.1 Access Log 🔝

Notice: When running SDK, slf4j implementation library is used for printing log. If the log implementation library is not configured when running the code example, and it prompts as follows:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

For more, refer to Frequently Asked Questions about SLF4J

The version between slf4j supported by the SDK and the corresponding log implementation is shown in the following table:

slf4j-api logback-classic slf4j-log4j12 slf4j-simple slf4j-jdk14
1.7.x 1.2.x 1.6.x/1.7.x 1.6.x/1.7.x 1.6.x/1.7.x

You can add corresponding library for log implementation according to actual situation of your target project. For example, you can add one of the following dependency to your pom.xml file:

logback

<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.3.12</version>
</dependency>

log4j

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.36</version>
</dependency>

slf4j simple

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <version>1.7.36</version>
</dependency>

jul

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-jdk14</artifactId>
    <version>1.7.36</version>
</dependency>

The SDK will print the access log by default, every request will be recorded to the console like:

16:53:04.905 [main] INFO HuaweiCloud-SDK-Access - "GET https://ecs.cn-southwest-2.myhuaweicloud.com/v1/077d6a6c19000fdd2f3bc00150080291/cloudservers/detail?offset=1&limit=25" 200 2251 deabe20c14f997a0291fc451a4da16a4 233
16:53:06.212 [main] INFO HuaweiCloud-SDK-Access - "PUT https://ecs.cn-southwest-2.myhuaweicloud.com/v1/077d6a6c19000fdd2f3bc00150080291/cloudservers/1aeac6fb-a2f2-48dc-9052-36637d119dd3" 200 880 f16f70e3fe245c11ab741760f8689a01 234
17:02:37.734 [main] INFO HuaweiCloud-SDK-Access - "GET https://ecs.cn-southwest-2.myhuaweicloud.com/v1/077d6a6c19000fdd2f3bc00150080291/cloudservers/detail?offset=1&limit=-1" 400 165 8c3c8b6fed4482d28e1929a78dc93f04 235

SDK access log name is "HuaweiCloud-SDK-Access", and out log format is:

"{httpMethod} {uri}" {httpStatusCode} {responseContentLength} {requestId} {durationMs}

Where:

  • requestId is the ID returned by HuaweiCloud API Gateway, which can be used for user guarantee or issue tracking.

You can shield access log in the log configuration depending on your project, or print access log to an independent file.

For example, you can turn off the access log in logback:

<logger name="HuaweiCloud-SDK-Access" level="OFF"> </logger>

6.2 Original HTTP Listener 🔝

In some situation, you may need to debug your http requests, original http request and response information will be needed. The SDK provides a listener function to obtain the original encrypted http request and response information.

⚠️ Warning: The original http log information is used in debugging stage only, please do not print the original http header or body in the production environment. These log information is not encrypted and contains sensitive data such as the password of your ECS virtual machine, or the password of your IAM user account, etc. When the response body is binary content, the body will be printed as "***" without detailed information.

import com.huaweicloud.sdk.core.HttpListener;
import com.huaweicloud.sdk.core.http.HttpConfig;

HttpConfig httpConfig = HttpConfig.getDefaultHttpConfig();

// Print the original request after registering the listener, do not use it in a production environment
HttpListener requestListener = HttpListener.forRequestListener(listener ->
        System.out.printf("> Request %s %s\n> Headers:\n%s\n> Body: %s\n",
                listener.httpMethod(),
                listener.uri(),
                listener.headers().entrySet().stream()
                        .flatMap(entry -> entry.getValue().stream().map(
                                value -> "\t" + entry.getKey() + ": " + value))
                        .collect(Collectors.joining("\n")),
                listener.body().orElse("")));
httpConfig.addHttpListener(requestListener);

// Print the original response after registering the listener, do not use it in a production environment
HttpListener responseListener = HttpListener.forResponseListener(listener ->
        System.out.printf("< Response %s %s %s\n< Headers:\n%s\n< Body: %s\n",
                listener.httpMethod(),
                listener.uri(),
                listener.statusCode(),
                listener.headers().entrySet().stream()
                        .flatMap(entry -> entry.getValue().stream().map(
                                value -> "\t" + entry.getKey() + ": " + value))
                        .collect(Collectors.joining("\n")),
                listener.body().orElse("")));
httpConfig.addHttpListener(responseListener);

VpcClient vpcClient = VpcClient.newBuilder()
    .withHttpConfig(httpConfig)
    .build();

7. API Invoker 🔝

7.1 Custom request headers 🔝

You can flexibly configure request headers as needed. Do not specify common request headers such as Host, Authorization, User-Agent, Content-Type unless necessary, as this may cause the errors.

EcsClient client = EcsClient.newBuilder()
    .withCredential(basicCredentials)
    .withRegion(EcsRegion.CN_NORTH_4)
    .withHttpConfig(config)
    .build();

String jobId = "{valid job id}";
ShowJobRequest request = new ShowJobRequest().withJobId(jobId);
try {
    ShowJobResponse response = client.showJobInvoker(request)
    // custom request headers
    .addHeader("key1", "value1")
    .addHeader("key2", "value2")
    .invoke();
    logger.info(response.toString());
} catch (SdkException e) {
    logger.error("", e);
}

7.2 Retry for request 🔝

When a request encounters a network exception or flow control on the interface, the request needs to be retried. The Java SDK provides the retry method for our users which could be used to the requests of GET HTTP method. The retry method has been supported on both synchronous client and asynchronous client, if you want to use the retry method, the following parameters are required: maxRetryTimes, retryCondition and backoffStrategy.

  • maxRetryTimes: the max value is 30, you could set to a positive integer no more than 30
  • retryCondition: a lambda function, which determine the condition of when to retry, the java SDK provides a default condition, and its code is:
/**
 * The default retry condition, if the exception is ConnectionException or subclass of ConnectionException, the request would be retried.
 *
 * @param <ResT> Generics of response classes
 * @return BiFunction returns true or false which means whether to retry
 */
public static <ResT> BiFunction<ResT, SdkException, Boolean> defaultRetryCondition() {
    return (resp, exception) -> {
        if (Objects.nonNull(exception)) {
            return ConnectionException.class.isAssignableFrom(exception.getClass());
        }
        return false;
    };
}
  • backoffStrategy: calculate the wait duration before next retry, the java SDK provides the default strategy which combines random backoff and exponential backoff as the algorithm to calculate the delay time before the next retry.

Now let's begin to introduce how could you use retry for different scenarios.

7.2.1 Synchronous Retry 🔝

If you want to use retry in synchronous client, you could use invoker() method in {Service}Client.

Take the interface ShowJob of ECS service for example, assume the request would retry at most 5 times, and the retry condition use the default condition, the code would be like the following:

// initialize the sychronous client
EcsClient client = EcsClient.newBuilder()
    .withCredential(basicCredentials)
    .withRegion(EcsRegion.CN_NORTH_4)
    .withHttpConfig(config)
    .build();

String jobId = "{valid job id}";
ShowJobRequest request = new ShowJobRequest().withJobId(jobId);
try {
    ShowJobResponse response = client.showJobInvoker(request)
    // max retry times
    .retryTimes(5)
    // retry condition, which would be retried for ConnectionException
    .retryCondition(BaseInvoker.defaultRetryCondition())
    .invoke();
    logger.info(response.toString());
} catch (SdkException e) {
    logger.error("", e);
}
7.2.2 Asynchronous Retry 🔝

If you want to use retry in asynchronous client, you could use invoker() method in {Service}Client.

Take the interface ShowJob of ECS service for example, assume the request would retry at most 5 times, and the retry condition use the default condition, the code would be like the following:

// initialize the asychronous client
EcsAsyncClient asyncClient = EcsAsyncClient.newBuilder()
    .withCredential(basicCredentials)
    .withRegion(EcsRegion.CN_NORTH_4)
    .withHttpConfig(config)
    .build();

String jobId = "{valid job id}";
ShowJobRequest request = new ShowJobRequest().withJobId(jobId);
try {
    ShowJobResponse response = asyncClient.showJobAsyncInvoker(request)
    // max retry times
    .retryTimes(5)
    // retry condition, which would be retried for ConnectionException
    .retryCondition(BaseInvoker.defaultRetryCondition())
    .invoke();
    logger.info(response.toString());
} catch (SdkException e) {
    logger.error("", e);
}
7.2.3 Typical Usage Scenarios 🔝

Scenario 1: If the response status code of the interface is 500(Server Error) or 429(Server Flow Control), retry for the request, and the code would be like the following:

String jobId = "{valid job id}";
ShowJobRequest request = new ShowJobRequest().withJobId(jobId);
try {
    ShowJobResponse response = client.showJobInvoker(request)
        .retryTimes(3)
        .retryCondition(
            (resp, ex) -> Objects.nonNull(ex) && ServiceResponseException.class.isAssignableFrom(ex.getClass())
                && (((ServiceResponseException) ex).getHttpStatusCode() == 429
                || ((ServiceResponseException) ex).getHttpStatusCode() == 500))
        .invoke();
    logger.info(response.toString());
} catch (InterruptedException e) {
    logger.error("InterruptedException", e);
} catch (ExecutionException e) {
    logger.error("ExecutionException", e);
}

Scenario 2: Retry for the specified job status, if the job status is success, then stop retry and do some other things, and the code would be like the following:

String jobId = "{valid job id}";
ShowJobRequest request = new ShowJobRequest().withJobId(jobId);
try {
    // base delay of retry in milliseconeds
    final int baseDelay = 1000;
    // max backoff time in retry
    final int maxBackoffInMilliseconds = 30000;

    ShowJobResponse response = client.showJobInvoker(request)
    // max retry times
    .retryTimes(10)
    // Request retry condition, set the retry condition to stop when the job status is success
    .retryCondition((resp, ex) -> Objects.nonNull(resp) && !resp.getStatus().equals(ShowJobResponse.StatusEnum.SUCCESS))
     // Request backoff policy, calculate the next request time after each request fails
     // Polling job status requires a long basic delay
    .backoffStrategy(new SdkBackoffStrategy(baseDelay, maxBackoffInMilliseconds))
    .invoke();
    logger.info(response.toString());
} catch (SdkException e) {
    logger.error("", e);
}

8. Upload and download files 🔝

8.1 Upload and download 🔝

Take the interface CreateImageWatermark of the service Data Security Center as an example, this interface needs to upload an image file and return the watermarked image file stream:

package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.dsc.v1.DscClient;
import com.huaweicloud.sdk.dsc.v1.model.CreateImageWatermarkRequest;
import com.huaweicloud.sdk.dsc.v1.model.CreateImageWatermarkRequestBody;
import com.huaweicloud.sdk.dsc.v1.model.CreateImageWatermarkResponse;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.function.Consumer;


public class CreateImageWatermarkDemo {

    public static void createImageWatermark(DscClient client) throws IOException {

        CreateImageWatermarkRequest request = new CreateImageWatermarkRequest();

        // Create a File object and a FileInputStream object.
        File file = new File("demo.jpg");
        FileInputStream fis = new FileInputStream(file);

        CreateImageWatermarkRequestBody body = new CreateImageWatermarkRequestBody()
                // Fill in file parameter.
                .withFile(fis, file.getName())
                .withBlindWatermark("test123");
        request.setBody(body);

        CreateImageWatermarkResponse response = client.createImageWatermark(request);
        fis.close();

        //Consumer of downloading files.
        Consumer<InputStream> consumer = inputStream -> {
            try {
                FileOutputStream out = new FileOutputStream("result.jpg");
                byte[] data = new byte[1024];
                int len = 0;
                while ((len = inputStream.read(data))!= -1) {
                    out.write(data, 0, len);
                }

                inputStream.close();
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        };

        //Download files.
        response.consumeDownloadStream(consumer);
    }

    public static void main(String[] args) throws IOException {
        String ak = System.getenv("HUAWEICLOUD_SDK_AK");
        String sk = System.getenv("HUAWEICLOUD_SDK_SK");
        String endpoint = "{your endpoint string}";
        String projectId = "{your project id}";
        BasicCredentials auth = new BasicCredentials()
                .withAk(ak)
                .withSk(sk)
                .withProjectId(projectId);

        DscClient client = DscClient.newBuilder()
                .withCredential(auth)
                .withEndpoint(endpoint)
                .build();

        createImageWatermark(client);

    }
    
}

8.2 Obtain progress 🔝

Take the PutObject and GetObject of the OBS service as an example:

package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.obs.v1.ObsClient;
import com.huaweicloud.sdk.obs.v1.ObsCredentials;
import com.huaweicloud.sdk.obs.v1.model.GetObjectRequest;
import com.huaweicloud.sdk.obs.v1.model.GetObjectResponse;
import com.huaweicloud.sdk.obs.v1.model.PutObjectRequest;
import com.huaweicloud.sdk.obs.v1.model.PutObjectResponse;
import com.huaweicloud.sdk.obs.v1.region.ObsRegion;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.function.Consumer;

public class ObsDemo {

    // Upload the object.
    public static void putObject(ObsClient client) throws IOException {
        PutObjectRequest request = new PutObjectRequest().withBucketName("bucketname").withObjectKey("objectname");
        FileInputStream fileInputStream = new FileInputStream("/tmp/file-to-upload");
        request.setUploadStream(fileInputStream);

        request.setProgressListener(progressStatus -> {
            // Obtain the average upload rate (B/S).
            System.out.println("AverageSpeed:" + progressStatus.getAverageSpeed());
            // Obtain the upload progress in percentage.
            System.out.println("TransferPercentage:" + progressStatus.getTransferPercentage());
        });
        // Refresh the upload progress each time 1 MB data is uploaded.
        request.setProgressInterval(1024 * 1024L);

        PutObjectResponse response = client.putObject(request);
        System.out.println(response.getHttpStatusCode());
        fileInputStream.close();
    }

    // Download the object.
    public static void getObject(ObsClient client) {
        GetObjectRequest request = new GetObjectRequest().withBucketName("bucketname").withObjectKey("objectname");

        request.setProgressListener(progressStatus -> {
            // Obtain the average download rate (B/S).
            System.out.println("AverageSpeed:" + progressStatus.getAverageSpeed());
            // Obtain the download progress in percentage.
            System.out.println("TransferPercentage:" + progressStatus.getTransferPercentage());
        });
        // Refresh the upload progress each time 1 MB data is downloaded.
        request.setProgressInterval(1024 * 1024L);

        GetObjectResponse response = client.getObject(request);
        System.out.println(response.getHttpStatusCode());

        //Consumer of downloading files.
        Consumer<InputStream> consumer = inputStream -> {
            try {
                FileOutputStream out = new FileOutputStream("/tmp/downloaded-file");
                byte[] data = new byte[1024];
                int len;
                while ((len = inputStream.read(data)) != -1) {
                    out.write(data, 0, len);
                }

                inputStream.close();
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        };
        response.consumeDownloadStream(consumer);
    }

    public static void main(String[] args) throws IOException {
        ObsCredentials credentials = new ObsCredentials()
                .withAk(System.getenv("HUAWEICLOUD_SDK_AK"))
                .withSk(System.getenv("HUAWEICLOUD_SDK_SK"));

        ObsClient client = ObsClient.newBuilder()
                .withCredential(credentials)
                .withRegion(ObsRegion.valueOf("cn-north-1"))
                .build();

        putObject(client);
        getObject(client);
    }
}