GraphQl implementation using webflux

Watch the implementation video

Implements a reactive GraphQL server using Spring WebFlux, enabling highly scalable endpoint queries.

Key Points

• Reactive Execution: Non-blocking data fetchers.

• Scalable: Ideal for high-concurrency scenarios.

• Performance: Handles thousands of concurrent requests with minimal overhead.

• Memory Efficient: Reduces memory footprint through backpressure handling.

---

The spring-boot-starter-graphql is a starter dependency for Spring Boot applications that allows them to integrate with GraphQL APIs. It provides a set of tools and libraries that enable developers to easily build GraphQL-based applications and expose them through a GraphQL endpoint. The starter includes support for GraphQL queries, mutations, subscriptions, and schema definitions, as well as integration with Spring Boot's autoconfiguration and dependency injection features.

Format code

./mvnw spotless:apply

Run tests

./mvnw clean verify

Run locally

docker-compose -f docker/docker-compose.yml up -d
./mvnw spring-boot:run -Dspring-boot.run.profiles=local

Using Testcontainers at Development Time

You can run TestApplication.java from your IDE directly. You can also run the application using Maven as follows:

./mvnw spring-boot:test-run

Useful Links

• Swagger UI: http://localhost:8080/swagger-ui.html

• Actuator Endpoint: http://localhost:8080/actuator

• GraphIQL: http://localhost:8080/graphiql

About Graph QL

GraphQL provides three main concepts:

1. Queries: Read data from the server

2. Mutations: Update data on the server

3. Subscriptions: Read data over a period of time (e.g., stock market updates, inflight recorder)

How to fetch data using URL

• There are two types of annotations that can be used expose API

  • @SchemaMapping(typeName = "Query", field = "customers") , Here typeName should be matching the schema declared in schema.graphqls and filed should match the definition

  • @QueryMapping , Short hand for @SchemaMapping where field if not specified will be obtained from methodname and it should be declared in schema.graphqls

Sample data

 {
    customers {
    id
    name
    orders {
        id
     }
   }
  }

or

{
    customers {
     id
    }
}

Fetching data based on name

{
    customersByName(name: "kolli") {
        id
        name
    }
}