Generating a Java SDK with LWA token exchange and authentication

Note to C# developers. We also provide a library for generating a C# SDK with LWA token exchange and authentication. For more information, see README.md in https://github.com/amzn/selling-partner-api-models/tree/main/clients/sellingpartner-api-aa-csharp.

These instructions show you how to generate a Java SDK for the Sellers API using Swagger Code Generator on a computer running Microsoft Windows. The process is the same for users of other operating systems such as macOS or Linux, with the replacement of Windows-specific semantics (for example, C:\). Although these instructions are for the Sellers API, you can modify the instructions to generate SDKs for any other Selling Partner API. See the Models page for Swagger models for each Selling Partner API section.

With this SDK you can make requests to the Selling Partner API with the following code already set up for you: Login with Amazon token exchange (exchange a refresh token for an access token) and authentication.

To generate a Java SDK with LWA token exchange and authentication

Install Java 8 or newer, Apache Maven 3.6. or greater, and GNU Wget and make them available in your $PATH.
Go to Models.
Clone the repository to make a local copy on your computer, if you haven't done so already.
Open a command prompt window and go to a directory where you want to download the Swagger Code Generator.
Download the latest version of the Swagger Code Generator.

For example:

wget https://repo1.maven.org/maven2/io/swagger/swagger-codegen-cli/2.4.13/swagger-codegen-cli-2.4.13.jar -O swagger-codegen-cli.jar

swagger-codegen-cli.jar downloads to the current directory.

Note: You can also download from maven.org by directing your browser here: https://repo1.maven.org/maven2/io/swagger/swagger-codegen-cli/2.4.13/swagger-codegen-cli-2.4.13.jar

Copy swagger-codegen-cli.jar into a directory structure that makes sense for you. For this example, we'll copy it to C:\SwaggerToCL.
Navigate to sellers.json in the selling-partner-api-models\models\sellers-api-model folder of your local copy of the repository.
Copy sellers.json into C:\SwaggerToCL.
Generate the SDK against the templates in the selling-partner-api-models\clients\sellingpartner-api-aa-java folder of your local copy of the repository. This folder contains an authorization and authentication library, along with customized templates for the Swagger Code Generator.

For example:

java -jar C:\SwaggerToCL\swagger-codegen-cli.jar generate -i C:\SwaggerToCL\Sellers.json -l java -t [path to selling-partner-api-models\clients\sellingpartner-api-aa-java folder]\resources\swagger-codegen\templates\ -o C:\SwaggerToCL\Sellers_JavaCL

The SDK is copied to C:\SwaggerToCL\Sellers_JavaCL

Build the AA Library and add it as a dependency of the SDK:
1. Navigate to the selling-partner-api-models\clients\sellingpartner-api-aa-java folder of your local copy of the repository and run mvn package. This generates a folder named "target". In this folder is a JAR file named sellingpartnerapi-aa-java-1.0-jar-with-dependencies.jar (or something similar) and all of the required dependencies.
2. Install the JAR file in your local Maven repository.
  
  For example:

mvn install:install-file -Dfile=[path to JAR file in "target" folder] -DgroupId=com.amazon.sellingpartnerapi -DartifactId=sellingpartnerapi-aa-java -Dversion=1.0 -Dpackaging=jar

You can find the actual groupId, artifactId, and version values near the top of the pom.xml file in the selling-partner-api-models\clients\sellingpartner-api-aa-java folder.

Add a dependency on the AA library in the pom.xml of the client library:

For example:

<dependency>
  <groupId>com.amazon.sellingpartnerapi</groupId>
  <artifactId>sellingpartnerapi-aa-java</artifactId>
  <version>1.0</version>
</dependency>

After you have generated your SDK you can use it to make calls to the Selling Partner API. See Connecting to the Selling Partner API using a generated Java SDK.