Hands-On Reactive Programming in Spring 5

Combining repository operations

Now, let's implement a slightly more complicated business use case. We may want to update a publication year for a book, and we only have the book's title. So, first, we have to find the desired book instance, then update the year of publishing, and save the book to the database. To make our use case even more complicated, let's assume that both the title and year values are retrieved asynchronously with some delay and are delivered by the Mono type. Also, we want to know whether our updated request was successful or not. So far, we do not require the update to be atomic and assume that there is always no more than one book with the same title. So, with those requirements we may design the following business ...