Spring Boot GraphQL

This provides examples to use GraphQL in a spring-boot based project.

GraphQL

GraphQL is a query language to retrieve data from a server. It is an alternative to REST, SOAP or gRPC in some way. It gives more power and flexibility to your API consumer to query only required data.

GraphQL Java

GraphQL-Java is the Java (server) implementation for GraphQL. This provides a low level libraries to define GraphQL schema and how the actual data for a query is fetched. You have to write a lot of boilerplate code if you use graphql-java.

Fortunately, We have two libraries available which provides a wrapper on top of graphql-java and saves use from writing boilerplate code. They are:-

1. GraphQL Java Kickstart
2. Netflix DGS

GraphQL Java Kickstart

GraphQL-Java-Kiskstart provides a wrapper on top of graphql-java and has following features:-

1. Provide comprehensive Spring boot configuration to customize GraphQL Java Server
2. Auto-detect schema files in src/main/resources/*.*/*.graphqls directory. This is where you write GraphQL schema, queries and mutation.
3. Concepts of Resolver. Implement GraphQLQueryResolver, GraphQLMutationResolver and GraphQLResolver<T> to specify how to fetch data for the queries, mutation and nested data respectively.
4. Easy integration with build tools such as GraphiQL, PlayGround and Voyager by adding runtime dependency. Provide comprehensive Spring Boot Configurations to customize these tools.
5. Easy to write integration test using GraphQLTestTemplate provided by test dependency.
6. Excellent tutorial series by Philip Starritt which gives you quick start.

Netflix DGS

Netflix-DGS is developed by Netflix on top of graphql-java and recently made it public to use. It has following features:-

1. Do not provide Spring boot based configurations
2. Auto-detect schema files in src/main/resources/schema/*.*/*.graphqls directory. This is where you write GraphQL schema, queries and mutation.
3. Concepts of DataFetcher. Provide annotations @DgsComponent at class level and @DgsQuery, @DgsMutation, @DgsData at method level to specify how to fetch data for the queries, mutation and nested data respectively.
4. Provide integration with GraphiQL
5. Provide good support to write unit and integration test cases using DgsQueryExecutor
6. Follow example to quick start