<dependency>
    <groupId>com.huaweicloud.sdk</groupId>
    <artifactId>huaweicloud-sdk-rds</artifactId>
    <version>3.1.5</version>
</dependency>

public class RdsDbUserDemo {
    private static final Logger logger = LoggerFactory.getLogger(RdsDbUserDemo.class.getName());

    public static void main(String[] args) {
        // 认证用的ak和sk直接写到代码中有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；
        // 本示例以ak和sk保存在环境变量中来实现身份验证为例，运行本示例前请先在本地环境中设置环境变量HUAWEICLOUD_SDK_AK和HUAWEICLOUD_SDK_SK。
        String ak = System.getenv("HUAWEICLOUD_SDK_AK");
        String sk = System.getenv("HUAWEICLOUD_SDK_SK");
        String regionId = "<YOUR REGION_ID>";
        String instanceId = "<YOUR INSTANCE_ID>";
        String name = "<YOUR NAME>";
        String password = "<YOUR PASSWORD>";
        int page = 1; // <YOUR PAGE>
        int limit = 10; // <YOUR LIMIT>

        RdsClient client = createClient(ak, sk);
        // 查看数据库用户列表
        listDatabaseUser(client, instanceId, page, limit);
        // 创建数据库用户
        createDatabaseUser(client, instanceId, name, password);
        // 查看数据库用户列表
        listDatabaseUser(client, instanceId, page, limit);
    }

    private static RdsClient createClient(String ak, String sk) {
        ICredential auth = new BasicCredentials().withAk(ak).withSk(sk);
        return RdsClient.newBuilder().withCredential(auth).withRegion(RdsRegion.CN_EAST_3).build();
    }

    private static void listDatabaseUser(RdsClient client, String instanceId, int page, int limit) {
        ListPostgresqlDbUserPaginatedRequest request = new ListPostgresqlDbUserPaginatedRequest();
        request.withInstanceId(instanceId);
        request.withPage(page);
        request.withLimit(limit);
        try {
            ListPostgresqlDbUserPaginatedResponse response = client.listPostgresqlDbUserPaginated(request);
            logger.info(response.toString());
        } catch (ConnectionException e) {
            logger.error("ConnectionException", e);
        } catch (RequestTimeoutException e) {
            logger.error("RequestTimeoutException", e);
        } catch (ServiceResponseException e) {
            logger.error("httpStatusCode: {}, errorCode: {}, errorMsg: {}", e.getHttpStatusCode(), e.getErrorCode(),
                e.getErrorMsg());
        }
    }

    private static void createDatabaseUser(RdsClient client, String instanceId, String name, String password) {
        CreatePostgresqlDbUserRequest request = new CreatePostgresqlDbUserRequest();
        request.withInstanceId(instanceId);
        PostgresqlUserForCreation body = new PostgresqlUserForCreation();
        body.withName(name);
        body.withPassword(password);
        request.withBody(body);
        try {
            CreatePostgresqlDbUserResponse response = client.createPostgresqlDbUser(request);
            logger.info(response.toString());
        } catch (ConnectionException e) {
            logger.error("ConnectionException", e);
        } catch (RequestTimeoutException e) {
            logger.error("RequestTimeoutException", e);
        } catch (ServiceResponseException e) {
            logger.error("httpStatusCode: {}, errorCode: {}, errorMsg: {}", e.getHttpStatusCode(), e.getErrorCode(),
                e.getErrorMsg());
        }
    }

}

{
    users: [
    {
        "name": "user_test_1",
        "attributes": {
            "rolsuper": false,
            "rolinherit": true,
            "rolcreaterole": true,
            "rolcreatedb": true,
            "rolcanlogin": true,
            "rolconnlimit": -1,
            "rolreplication": true,
            "rolbypassrls": false
           },
        "memberof":  ["pg_monitor", "pg_read_all_stats", "pg_stat_scan_tables", "pg_signal_backend"]
    }]
    "totalCount": 1
}

class CreatePostgresqlDbUserResponse {
    "resp": "successful"
}

{
    "users": [
    {
        "name": "user_test_1",
        "attributes": {
            "rolsuper": false,
            "rolinherit": true,
            "rolcreaterole": true,
            "rolcreatedb": true,
            "rolcanlogin": true,
            "rolconnlimit": -1,
            "rolreplication": true,
            "rolbypassrls": false
           },
        "memberof": ["pg_monitor", "pg_read_all_stats", "pg_stat_scan_tables", "pg_signal_backend"]
    }, 
    {
        "name": "user_test_2",
        "attributes": {
            "rolsuper": false,
            "rolinherit": true,
            "rolcreaterole": true,
            "rolcreatedb": true,
            "rolcanlogin": true,
            "rolconnlimit": -1,
            "rolreplication": true,
            "rolbypassrls": false
        },
        "memberof": []
    }],
    "totalCount": 2
}