MasteryTask02.md

Mastery Task 2: Submit to the process

We currently have an API to retrieve books, but we need a way to submit Kindle books for publishing so we can continue to grow our catalog!

Publishing a Kindle book is a long, multi-step process, so we can’t complete the whole process within a single API call. To handle this, we’ve decided to save each book publish request into a class called BookPublishRequestManager that will allow requests to be processed later. That way the caller of SubmitBookForPublishing gets an immediate response with a publishingRecordId that they can use to check back on the status of their book publish request by calling GetPublishingStatus. This is similar to the workflow for orders on the Amazon retail website — you place an order and get an orderId back, which you can use later to check the current status of your order. This is known as asynchonous processing, since our service doesn't make the user wait until the entire publishing process completes.

The BookPublishRequestManager should manage a collection of book publish requests, ensuring that requests are processed in the same order that they are submitted.

You will need to do the following:

• Create the BookPublishRequestManager class in the com.amazon.ata.kindlepublishingservice.publishing package.
• The BookPublishRequest class has been provided to you in the com.amazon.ata.kindlepublishingservice.publishing package.
• Implement BookPublishRequestManager's addBookPublishRequest method which adds the given BookPublishRequest to the collection.
• Implement getBookPublishRequestToProcess which retrieves the next BookPublishRequest in line for publishing and returns it. If there are no requests to publish this should return null. This will be called in a later task when we implement processing the book publish requests.
• Since nothing is currently using the BookPublishRequestManager we don't need to update any Dagger classes yet. We can still set ourselves up with a more testable BookPublishRequestManager class by accepting any dependencies of our class into our constructor.

The SubmitBookForPublishingActivity currently only saves an item in the PublishingStatus table to record that we have received the book publish request to be processed. Now that you have the BookPublishRequestManager, finish the SubmitBookForPublishing operation by updating SubmitBookForPublishingActivity, to add BookPublishRequests to the manager for processing, based on the design doc's implementation notes and diagram.

We need to ensure we have added the correct Provider methods and annotated our constructors properly to make inject our BookPublishRequestManager. The service is already setup to use Dagger.

Finally, in order to make sure we only attempt to publish books in our catalog, you will need to add a new void method validateBookExists to the CatalogDao class, which the activity can call to check if the provided bookId exists in the catalog, and throws a BookNotFoundException if it doesn’t. This is to meet the requirement in the design doc where the book’s latest version in the catalog can be active or inactive, since we will allow users to publish a new version of an inactive book. Make sure to add additional unit tests for this case!

To test your new API, try submitting requests with a non-existant bookId, with an active bookId, and with an inactive bookId to ensure you are getting expected results back.

Run MasteryTaskTwoSubmitBookForPublishingTeststo validate your changes.

Exit Checklist:

• You’ve built BookPublishRequestManager, which includes methods for adding and retrieving BookPublishRequests.
• You’ve updated SubmitBookForPublishingActivity according to the design doc, which allows books to be submitted for publishing and returns a response with a publishingRecordId.
• You added unit tests to cover your new code.
• MasteryTaskTwoSubmitBookForPublishingTests and MasteryTaskTwoBookPublishRequestManagerTests passes