Typical REST APIs deal in resources. This is fine for many use cases, but it tends to be more rigid and less efficient in others.

For example, in an shopping API, it's important to weigh how much or how little information should be provided in a request for an order resource? Should the order resource contain only order specifics, but no details about the order's line items or the products in those line items? If all relevant details is included in the response, then it's breaking the boundaries of what the resource should offer and is overkill for clients that do not need it. On the other hand, proper factoring of the resource will require that the client make multiple requests to the API to fetch relevant information that they may need.

GraphQL offers a more flexible alternative to REST, setting aside the resource-oriented model and focusing more on what a client needs. Much as how SQL allows for data from multiple tables to be selected and joined in response to a query, GraphQL offers API clients the possibility of tailoring the response to provide all of the information needed and nothing that they do not need.

In this example-driven session, we're going to look at how to implement GraphQL in Spring. You'll learn how Spring for GraphQL builds upon GraphQL Java, recognize the use-cases that are best suited for GraphQL, and how to build a GraphQL API in Spring.