Alibaba Cloud SDK:Generic calls

Alibaba Cloud SDK for Java V2.0 supports generic API calls, which allow you to call any OpenAPI operation without installing service-specific SDKs.

Benefits

Lightweight: Only the SDK core library is required. No service-specific SDKs needed.

Easy to use: Build common request parameters, call a common client, and receive responses in a standard format.

For more information, see Generic calls and specialized calls.

Before you begin

Before you make a generic call, view the API metadata to get the API style, parameters, and URL. For more information, see OpenAPI metadata.

Install the SDK core library

Add the following dependency to your pom.xml file. Check Maven Repository for the latest version.

<dependency>
    <groupId>com.aliyun</groupId>
    <artifactId>tea-openapi</artifactId>
    <version>0.3.10</version>
</dependency>

Call an API operation

Initialize a request client

Create a com.aliyun.teaopenapi.Client object to initialize a request client. You can also use the Credentials tool for authentication. For more information about the Credentials tool, see Manage credentials.

        // 1. Initialize a request client
        com.aliyun.teaopenapi.models.Config config = new com.aliyun.teaopenapi.models.Config();
        config.setAccessKeyId(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID"));
        config.setAccessKeySecret(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET"));
        // Specify the endpoint of ASAPI.
        config.setEndpoint("ecs.cn-hangzhou.aliyuncs.com");
        // Optional. Configure a proxy by using the Config object when you initialize the client. 
        // Specify HTTPS as the protocol when you initialize the client.
        // config.setProtocol("HTTPS");
        // Specify the region ID.
        // config.setRegionId("<regionId>");
        // Configure a proxy when you initialize the client.
        // config.setHttpProxy("http://127.0.0.1:9898");
        // config.setHttpsProxy("http://user:password@127.0.0.1:8989");
        // config.setNoProxy("127.0.0.1,localhost");
        // Configure timeout periods when you initialize the SDK client.
        // The default timeout period for connection requests is 5,000 milliseconds. The value is calculated by using the formula: 5 × 1,000 = 5,000.
        // config.setConnectTimeout(5000);
        // The default timeout period for read requests is 10,000 milliseconds.
        // config.setReadTimeout(10000);
        com.aliyun.teaopenapi.Client client = new com.aliyun.teaopenapi.Client(config);

//        //  Use the Credentials tool
//        com.aliyun.credentials.models.Config credentialConfig = new com.aliyun.credentials.models.Config();
//        credentialConfig.setType("access_key");
//        credentialConfig.setAccessKeyId(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID"));
//        credentialConfig.setAccessKeySecret(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET"));
//        com.aliyun.credentials.Client credentialClient = new com.aliyun.credentials.Client();
//        com.aliyun.teaopenapi.models.Config config = new com.aliyun.teaopenapi.models.Config()
//                .setCredential(credentialClient)
//                .setEndpoint("ecs.cn-hangzhou.aliyuncs.com");
//        com.aliyun.teaopenapi.Client client = new com.aliyun.teaopenapi.Client(config);

Configure API operation details

Use com.aliyun.teaopenapi.models.Params to configure the API style, version, and request method. The following example calls DescribeInstanceTypeFamilies.

        com.aliyun.teaopenapi.models.Params params = new com.aliyun.teaopenapi.models.Params()
                .setStyle("RPC")  // The API style, such as remote procedure call (RPC) or resource-oriented architecture (ROA). 
                .setVersion("2014-05-26") // The API version. 
                .setMethod("POST") // The request method. 
                .setAction("DescribeInstanceTypeFamilies")  // The name of the API operation. 
                .setPathname("/") // The URL of the operation. The default path of an RPC-style operation is /. You can obtain the URL of an ROA-style operation from the data.path parameter in the API metadata. 
                .setProtocol("HTTPS") // The request protocol, such as HTTPS or HTTP. We recommend that you use HTTPS. 
                .setAuthType("AK") // The authentication type. Use the default type. If the operation supports anonymous requests, you can specify the Anonymous parameter to initiate an anonymous request. 
                .setReqBodyType("json") // The type of request body. Valid values: byte, json, and formData. 
                .setBodyType("json"); // The response format. JSON is supported.

Configure request parameters

Use com.aliyun.teaopenapi.models.OpenApiRequest to pass request parameters through a query string, body, or stream. Choose the method based on the API metadata. For example, RegionId in DescribeInstanceTypeFamilies is defined as {"name":"RegionId","in":"query",...}}, where "in":"query" means it is passed as a query parameter.

How the parameter is passed	Scenario
setQuery	Metadata defines "in":"query". Pass parameters in setQuery.
setBody	Metadata defines "in":"body'' or "in": "formData". Pass parameters in setBody and set reqBodyType to match the body format.
setStream	Use setStream to pass file streams for file uploads.

        // Scenario 1: Configure a query string.
        java.util.Map<String, Object> queries = new java.util.HashMap<>();
        queries.put("RegionId", "cn-hangzhou");
        com.aliyun.teaopenapi.models.OpenApiRequest request = new com.aliyun.teaopenapi.models.OpenApiRequest()
                .setQuery(com.aliyun.openapiutil.Client.query(queries));

//        // Method 2: Configure the body and set reqBodyType to json.
//        java.util.Map<String, Object> body = new java.util.HashMap<>();
//        body.put("param1", "value1");
//        body.put("param2", "value2");
//        com.aliyun.teaopenapi.models.OpenApiRequest request = new com.aliyun.teaopenapi.models.OpenApiRequest()
//                .setBody(com.aliyun.openapiutil.Client.query(body));

//        // Method 3: Configure the body and set reqBodyType to formData.
//        java.util.Map<String, Object> formData = new java.util.HashMap<>();
//        formData.put("param1", "value1");
//        formData.put("param2", "value2");
//        com.aliyun.teaopenapi.models.OpenApiRequest request = new com.aliyun.teaopenapi.models.OpenApiRequest()
//                .setBody(formData);

//        // Method 4: Configure the Stream parameter to pass file streams
//        com.aliyun.teaopenapi.models.OpenApiRequest request = new com.aliyun.teaopenapi.models.OpenApiRequest()
//                .setStream("<FILE_STREAM>");  // Replace <FILE_STREAM> with the actual file stream.

Send the request

Call callApi on the com.aliyun.teaopenapi.Client object. You can specify runtime parameters such as timeouts and proxies. For more information, see Advanced settings.

        // Configure runtime options.
        com.aliyun.teautil.models.RuntimeOptions runtime = new com.aliyun.teautil.models.RuntimeOptions();
// Disable SSL certificate authentication.
//        runtime.ignoreSSL = true;
// Enable the automatic retry mechanism.
//        runtime.autoretry = true;
// Specify the number of automatic retries.
//        runtime.maxAttempts = 3;
// Specify the connection timeout period.
//        runtime.connectTimeout = 5000;
// Specify the timeout period of read requests.
//       runtime.readTimeout = 10000;
        // The response is of the MAP type, which contains the response body, response headers, and HTTP status code. 
        java.util.Map<String, ?> response = client.callApi(params, request, runtime);
        System.out.println(new com.google.gson.Gson().toJson(response));

Examples

Example: Call an RPC-style API operation

The following example makes a generic call to the ECS DescribeInstanceTypeFamilies operation.

import com.aliyun.teaopenapi.Client;
import com.aliyun.teaopenapi.models.Config;
import com.aliyun.teaopenapi.models.OpenApiRequest;
import com.aliyun.teaopenapi.models.Params;
import com.aliyun.teautil.models.RuntimeOptions;
import com.google.gson.Gson;

import java.util.HashMap;
import java.util.Map;

import static com.aliyun.openapiutil.Client.query;

public class Sample {
    public static void main(String[] args) throws Exception {
        Config config = new Config()
                .setAccessKeyId(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID"))
                .setAccessKeySecret(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET"))
                .setEndpoint("ecs-cn-hangzhou.aliyuncs.com");
        Client client = new Client(config);
        Params params = new Params()
                .setStyle("RPC")  // The API style.
                .setVersion("2014-05-26") // The version number of the operation.
                .setMethod("POST") // The HTTP method of the operation.
                .setAction("DescribeInstanceTypeFamilies")  // The name of the API operation.
                .setPathname("/") 
                .setProtocol("HTTPS")
                .setAuthType("AK")
                .setReqBodyType("json")
                .setBodyType("json");
        // Specify the query parameters.
        Map<String, Object> queries = new HashMap<>();
        queries.put("RegionId", "cn-hangzhou");
        // Create a runtime configuration object.
        RuntimeOptions runtime = new RuntimeOptions();
        OpenApiRequest request = new OpenApiRequest()
                .setQuery(query(queries));
        // The response is of the MAP type, which contains the response body, response headers, and HTTP status code. 
        Map<String, ?> response = client.callApi(params, request, runtime);
        System.out.println(new Gson().toJson(response));
    }
}

Example: Call a RESTful-style (ROA-style) API operation

The following example makes a generic call to the ACK DescribeClustersV1 operation.

import com.aliyun.teaopenapi.Client;
import com.aliyun.teaopenapi.models.Config;
import com.aliyun.teaopenapi.models.OpenApiRequest;
import com.aliyun.teaopenapi.models.Params;
import com.aliyun.teautil.models.RuntimeOptions;
import com.google.gson.Gson;

import java.util.HashMap;
import java.util.Map;

import static com.aliyun.openapiutil.Client.query;

public class Test3 {
    public static void main(String[] args_) throws Exception {
        Config config = new Config()
                .setAccessKeyId(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID"))
                .setAccessKeySecret(System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET"))
                .setEndpoint("cs.cn-hangzhou.aliyuncs.com");
        Client client = new Client(config);
        Params params = new Params()
                .setStyle("ROA") // The API style.
                .setVersion("2015-12-15") // The API version.
                .setAction("DescribeClustersV1") // The operation that you want to call.
                .setPathname("/api/v1/clusters") // The API URI.
                .setMethod("GET") // The request method.
                .setProtocol("HTTPS")
                .setAuthType("AK")
                .setReqBodyType("json")
                .setBodyType("json");
        // Specify the query parameters.
        Map<String, Object> queries = new HashMap<>();
        queries.put("name", "cluster-demo");
        OpenApiRequest request = new OpenApiRequest()
                .setQuery(query(queries));
        RuntimeOptions runtime = new RuntimeOptions();
        // The response is of the MAP type, which contains the response body, response headers, and HTTP status code. 
        Map<String, ?> response = client.callApi(params, request, runtime);
        System.out.println(new Gson().toJson(response));
    }
}