A reference implementation for Realtime GraphQL Subscription API in Spring Boot using GraphQL Java Tools and GraphQL Spring Boot starter.

Step by step tutorial at: Spring Boot GraphQL Subscription Realtime API

1. Java 11
2. Spring Boot 2.3.0
3. Gradle 6.3
4. GraphQL Java

./gradlew bootRun

Open http://localhost:8080/graphiql for GraphQL introspection.

GraphQL Request

subscription {
  stockPrice(symbol:"GOOG") {
    price
    symbol
    timestamp
  }
}

Response

{
  "stockPrice": {
    "price": "0.7490690579285905",
    "symbol": "GOOG",
    "timestamp": "2020-05-22T22:16:12.092143"
  }
}