ccaspanello / graphql-sandbox

GraphQL Sandbox

The intent of this project is to learn how we can cleanly call GraphQL libraries from Java.

Building

It's a Maven project. Simply run mvn clean install

Configuration

GitHub does not allow anonymous access to the V4 API. You can add this in the test.properties file

Source Generation

The apollo-client-maven-plugin is used to build Java objects based on GraphQL schema & query files. For example the source.graphql file contains:

query Source($repoName:String!, $repoOwner:String!, $blob:String!){
     repository(owner: $repoOwner, name: $repoName) {
       content:object(expression: $blob) {
         ... on Blob {
           text
         }
       }
     }
   }

This is a GraphQL query that will fetch the file contents based on the repository, branch, and path. When the Maven plugin runs it will generate objects to build this query in a type safe way. For example:

BlameQuery query = BlameQuery.builder()
  .repoOwner(repoOwner)
  .repoName(repoName)
  .ref(ref)
  .path(path)
  .blob(ref + ":" + path)
  .build();

Note: If you want to play around with GraphQL and learn how to create GraphQL queries you can check out the GitHub Explorer

Creating the Client

These query objects are used with the Apollo Client, which uses the OkHTTP Client.

OkHttpClient okHttpClient = new OkHttpClient.Builder()
  .addInterceptor(chain -> chain.proceed(chain.request().newBuilder().addHeader("Authorization", "Bearer " + token).build()))
  .build();
   
ApolloClient client = ApolloClient.builder()
  .serverUrl(url)
  .okHttpClient(okHttpClient)
  .build();

Executing Query

This client can then be called with the following:

client.query(query).enqueue(new ApolloCall.Callback<Optional<BlameQuery.Data>>() {
    @Override
    public void onResponse(@NotNull Response<Optional<BlameQuery.Data>> response) {
      . . .
    }
    @Override
    public void onFailure(@NotNull ApolloException e) {
      . . .
    }
  }
);