Testing the implementation of the API

Once the code is ready to run, you can compile and build the artifact using the following command from the root folder of the project:

$ ./gradlew clean build

The previous command removes the build folder and generates the artifact (the compiled classes and JAR). After the successful build, you can run the application using the following command:

$ java -jar build/libs/Chapter03-0.0.1-SNAPSHOT.jar

Now, we can perform tests using the curl command:

$ curl --request GET 'http://localhost:8080/api/v1/carts/1' --header 'Accept: application/xml'

This command calls the GET request for /carts with ID 1. Here, we demand the XML response using the Accept header, and we get the following response:

<Error>  <errorCode>PACKT-0001</errorCode>
  <message>The system is unable to complete the request.
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