Builds

graphql-orchestrator-java is a library that exposes data from various GraphQL microservices using a single unified GraphQL schema. It uses a recursive strategy to aggregate and combine the schemas from these micro-services and orchestrates the graphql queries to the appropriate services at runtime.

It uses the graphql-java library as the runtime execution engine on the unified schema.

Getting Started

Dependency

<dependency>
    <groupId>com.intuit.graphql</groupId>
    <artifactId>graphql-orchestrator-java</artifactId>
    <version>${graphql.orchestrator.version}</version>
</dependency>

Usage in code

• Implement the ServiceProvider interface. You will a new instance for each GraphQL Service.

class TemplateServiceProvider implements ServiceProvider {

  public static final String TEMPLATE = "type Query { nested: Nested } type Nested { %s: String}";
  private String field;

  public TemplateServiceProvider(String field) { this.field = field; }

  // Unique namespace for the service
  @Override
  public String getNameSpace() { return field; }

  // GraphQL Schema
  @Override
  public Map<String, String> sdlFiles() {
    return ImmutableMap.of(field + ".graphqls", String.format(TEMPLATE, field));
  }

  // Query execution at runtime, the response needs to have data and error objects as per GraphQL Spec
  @Override
  public CompletableFuture<Map<String, Object>> query(final ExecutionInput executionInput, 
      final GraphQLContext context) {
    //{'data':{'nested':{'%s':'%s'}}}"
    Map<String, Object> data = ImmutableMap
        .of("data", ImmutableMap.of("nested", ImmutableMap.of(field, field)));
    return CompletableFuture.completedFuture(data);
  }
}

• Create an instance of Orchestrator and execute the query as below.

    // create a runtimeGraph by stitching service providers
    RuntimeGraph runtimeGraph = SchemaStitcher.newBuilder()
        .service(new TemplateServiceProvider("foo"))   
        .service(new TemplateServiceProvider("bar"))  
        .build()
        .stitchGraph();

    // pass the runtime graph to GraphQLOrchestrator
    GraphQLOrchestrator graphQLOrchestrator = GraphQLOrchestrator.newOrchestrator()
        .runtimeGraph(runtimeGraph).build();
    
    //Execute the query 
    CompletableFuture<ExecutionResult> execute = graphQLOrchestrator
        .execute(ExecutionInput.newExecutionInput().query("query {nested {foo bar}}").build());

    ExecutionResult executionResult = execute.get();
    System.out.println(executionResult.getData().toString());
    // Output: {nested={foo=foo, bar=bar}}

---

Documentation

Detailed Documentation can be found here

Contributing

Read the Contribution guide