Implementing Data Resolvers
Write resolver functions in Spring Boot to fetch data for your defined GraphQL fields from various sources.
What are Data Resolvers?
Welcome! In GraphQL, clients ask for specific data. But how does your server know where to get that data?
That's where Data Resolvers come in! A resolver is a function or method that knows how to fetch the data for a specific field in your GraphQL schema.
- They act as the bridge between your schema and your data sources (like databases, APIs, or even simple in-memory lists).
- Each field in your schema needs a resolver, implicitly or explicitly.
Resolvers in Spring for GraphQL
Spring for GraphQL makes implementing resolvers straightforward. It uses annotations to map Java methods directly to fields in your GraphQL schema.
You'll typically write these resolver methods inside Spring @Controller classes. Spring automatically scans these controllers and connects their methods to the GraphQL schema fields based on naming conventions or explicit annotations.
All lessons in this course
- Defining Custom Data Types
- Implementing Data Resolvers
- Executing Simple GraphQL Queries
- GraphQL Mutations: Changing Data