Examples

Helloworld HTTP Server

This example showcases generating a GraphQL schema from a simple gRPC service. The GraphQL server makes rpc calls to the backend server.

To run the example you need to run the backend gRPC server first, then run the GraphQL frontend server.

1. Build and run the gRPC backend server

   From the top level directory run these commands:

   > cd examples
   > ./gradlew installDist
   > ./build/install/examples/bin/helloworld-backend
   
   

2. Run the GraphQL frontend server

   In another terminal run the following command:

   > ./build/install/examples/bin/helloworld-graphqlserver
   

3. Visit GraphiQL and make requests

   • http://localhost:8080

Streaming GraphQL using gRPC

This example showcases a streaming GraphQL response. The goal is to support the @streaming directive.

Note: This is a work in progress

1. Run the gRPc backend server

   > cd examples
   > ./gradlew installDist
   > ./build/install/examples/bin/streaming-backend
   

2. Run the GraphQL frontend gRPC server

   > cd examples
   > ./build/install/examples/bin/streaming-graphql-server
   

3. Run the GraphQL gRPC client

   > cd examples
   > ./build/install/examples/bin/streaming-graphql-client
   

Current Limitations of Streaming Demo

• The response is always streaming (it doesn't depend on the presents of the @streaming directive)
• The demo is using a gRPC service for the GraphQL API (no HTTP/JSON demo).
• The data field of the top level GraphQL Response proto is a JSON encoded string of the response (it could be either Any or oneOf())
• Variables are not used in the demo
• Errors are not returned in the response

Library Example

The library example uses DataLoaders which provides a request-scoped cache and automatically batches requests.

Community Examples

github.com/dbaggett/medallion contains multiple microservices and uses Kotlin instead of Java.