Java SDK overview

Integrate applications running on the Java Virtual Machine (JVM) with Composable Commerce.

The Java SDK (also referred to as the Java v2 SDK) enables you to use Java 8 methods and objects to interact with the HTTP API, Import API, Audit Log API, and Checkout API. With the Java SDK, you can make use of IDE autocompletion, type-safety, encapsulation, and an internal domain-specific language for formulating valid requests.

The Java SDK supports multiple languages that run on the JVM, including Java, Scala, Groovy, Clojure, and Kotlin.

Learn more about configuring your integrated developer environment in our self-paced Prepare your work environment module.

Get started

Learn how to set up and use the Java SDK with our get started guide.

Refer to our integration tests for examples of creating, querying, updating, and deleting resources in your Composable Commerce Project.

The Java SDK is open source and is available on GitHub under the Apache License, where you can also find its release notes.

You can view the full Javadoc reference on GitHub.

Migration from v1

If you're upgrading from the v1 SDK, our migration guide provides detailed instructions.

SDK features

The Java SDK uses various Java 8 language constructs and classes, including:

As a result of Java 8 dependencies, the Java SDK is unsuitable for Android development as it does not support Java 8 on its virtual machine.

The SDK simplifies development with:

Default implementations for equals() and hashCode(): automatically using reflection in model implementation classes.
Client interfaces: the HTTP client abstract is a functional interface, and you can replace it with test doubles.
Model factory methods: each model has a factory method ::of() to create a new empty instance. The method ::builder() returns a new builder instance.
Helper methods: you can find a complete list of helper methods including example usage in the Javadoc.

Best practices and error handling

You can find a complete list of best practices on GitHub

Exceptions

The Java SDK uses exceptions from the Java Development Kit (such as IllegalArgumentException) and provides its own exceptions which inherit from BaseException.

Problems related to the ApiHttpClient result in an ApiHttpException.
JSON serializing and deserializing problems result in a JsonException.
ApiHttpException is a base exception for all error responses (HTTP status codes 4xx and 5xx).
ApiClientException indicates the client-side errors that can be recovered (HTTP status codes 4xx).
ApiServerException represents server errors.

Errors

If a command cannot run due to unfulfilled preconditions, one error response with multiple errors can be returned (for more information, see HTTP API Errors). The Java SDK then adds a BadRequestException into a CompletionStage.

Custom HttpExceptionFactory

The Java SDK treats responses with HTTP status codes 4xx and 5xx as errors and raises exceptions. The DefaultHttpExceptionFactory creates these exceptions. To customize the handling, you must implement this interface and override its default methods as needed.

public class HttpExceptionFactoryTest {

  static class CustomExceptionFactory implements HttpExceptionFactory {

    @Override
    public ApiHttpException create(
      ApiHttpRequest request,
      ApiHttpResponse<byte[]> response
    ) {
      return new ApiHttpException(
        response.getStatusCode(),
        request.getSecuredBody(),
        response.getHeaders(),
        "something bad happened",
        response,
        request
      );
    }

    @Override
    public ResponseSerializer getResponseSerializer() {
      return ResponseSerializer.of();
    }
  }

  @Test
  public void customFactory() {
    ProjectApiRoot client = ApiRootBuilder
      .of()
      .defaultClient(ServiceRegion.GCP_EUROPE_WEST1.getApiUrl())
      .withHttpExceptionFactory(CustomExceptionFactory::new)
      .build("my-project-key");

    assertThatExceptionOfType(ApiHttpException.class)
      .isThrownBy(() -> client.get().executeBlocking())
      .withMessageStartingWith("detailMessage: something bad happened");
  }
}

Logging

Internal logging used by the commercetools client itself uses a SLF4J logger named commercetools.

The default logger middleware logs the following information per level:

Error: logs HTTP method, URI, and response status code for ApiHttpException, and cause and exceptions for all other exceptions.
Information: logs HTTP method, URI, response status code, and any deprecation notices. You can configure the log level when instantiating the InternalLoggerMiddleware.
Debug: logs string representations of the request and the response, including headers and body, with sensitive data like auth tokens and passwords, redacted.
Trace: Logs request and response with pretty-printed output, with sensitive information redacted.

Logger hierarchy

The loggers form a hierarchy separated by a period. The root logger is commercetools. The child loggers of commercetools are the endpoints. For example commercetools.categories for Categories and commercetools.product-types for Product Types.

The grandchild loggers refer to the action. commercetools.categories.request refers to performing requests per HTTPS to commercetools for Categories, commercetools.categories.response refers to the responses.

The logger makes use of different log levels, so for example commercetools.categories.response logs the HTTP response on debug level:

 [OkHttp https://api.europe-west1.gcp.commercetools.com/...] DEBUG commercetools.categories.response - io.vrap.rmf.base.client.ApiHttpResponse@33e37acd[statusCode=200,headers=...,textInterpretedBody={"limit":20,"offset":0,"count":4,"total":4,"results":[{"id":"ca7f64dc-ab41-4e7f-b65b-bfc25bf01111","version":1,"createdAt":"2021-01-06T09:21:55.445Z","lastModifiedAt":"2021-01-06T09:21:55.445Z","key":"random-key-15aab6ee-9a48-4fdc-a8c3-8ff9ff390d60","name":{"key-6bc3cc62-1995-43f4":"value-random-string-c3ff7f1a-6371-4c0c-a3b9-5060eca08b8a"},"slug":{"key-6bc3cc62-1995-43f4":"value-random-string-c3ff7f1a-6371-4c0c-a3b9-5060eca08b8a"},"description":{"key-6bc3cc62-1995-43f4":"value-random-string-c3ff7f1a-6371-4c0c-a3b9-5060eca08b8a"},"ancestors":[],"orderHint":"random-string-a99e6941-3225-4766-923a-4a654652532f","externalId":"random-id-100b3851-29b4-47c1-aef3-860b4cd28f54"}]}]

Additionally, commercetools.categories.response logs the formatted HTTP response on trace level:

[OkHttp https://api.europe-west1.gcp.commercetools.com/...] TRACE commercetools.categories.response - 200
 {
   "limit" : 20,
   "offset" : 0,
   "count" : 4,
   "total" : 4,
   "results" : [ {
     "id" : "bcb15128-b69e-47b6-81c4-1ea5f9a63b83",
     "version" : 1,
     "createdAt" : "2021-01-06T09:21:50.485Z",
     "lastModifiedAt" : "2021-01-06T09:21:50.485Z",
     "createdBy" : {
       "clientId" : "h-QvaF3NpsjPBWeXa6TUOnq0",
       "isPlatformClient" : false
     },
     "key" : "random-key-f45535f5-1111-4bfb-98ac-164234ac2c73",
     "name" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     },
     "slug" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     },
     "description" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     },
     "ancestors" : [ ],
     "orderHint" : "random-string-6b88f299-d4ca-491a-9d7c-3463e718c8d2",
     "externalId" : "random-id-b98a5ab4-5413-40b3-8119-eb5ac2b5afbb",
     "metaTitle" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     },
     "metaKeywords" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     },
     "metaDescription" : {
       "key-b7d87008-9526-47b3-8b80" : "value-random-string-baf1a1ae-3726-4573-bec5-2c53c7d1114a"
     }
   }, {
   ...
   } ]
 }

commercetools.products.responses.queries only logs HTTP GET requests and commercetools.products.responses.commands only logs HTTP POST/DELETE requests.

[pool-1-thread-1] DEBUG commercetools.products.request.commands - io.vrap.rmf.base.client.ApiHttpRequest@1d2c6948[method=POST,uri="https://api.europe-west1.gcp.commercetools.com/test-php-dev-integration-1/products",headers=[...],textInterpretedBody={"productType":{"id":"cda39953-23af-4e85-abb0-5b89517ec5f2","typeId":"product-type"},"name":{"random-string-b66de021-d2fa-4262-8837-94a6992a8cdc":"random-string-da28a010-e66b-49d4-a18b-f1bfc145d2f6"},...}]
 [pool-1-thread-1] DEBUG commercetools.products.request.queries - io.vrap.rmf.base.client.ApiHttpRequest@53667fdb[method=GET,uri="https://api.europe-west1.gcp.commercetools.com/test-php-dev-integration-1/products/ef745227-b115-4132-ba2c-4e46db80df79",headers=[...],textInterpretedBody=empty body]

Java SDK overview

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