This module implements a GraphQL Java Servlet. It also supports Relay.js, Apollo and OSGi out of the box.

compile 'com.smartling.graphql-java:graphql-java-servlet:4.7.1-SNAPSHOT' 

Build Plan: http://jenkins.data.dev.smartling.net/job/GraphQL%20Java%20Servlet/

You can download releases from maven central:

repositories { mavenCentral() } dependencies { compile 'com.graphql-java:graphql-java-servlet:4.6.1' }

<dependency> <groupId>com.graphql-java</groupId> <artifactId>graphql-java-servlet</artifactId> <version>4.6.1</version> </dependency>

The servlet supports the following request formats:

• GET request to ../schema.json: Get the result of an introspection query.
• GET request with query parameters (query only, no mutation):
  • query
  • operationName (optional)
  • variables (optional)
• POST body JSON object with fields:
  • query
  • operationName (optional)
  • variables (optional)
• POST multipart part named "graphql" containing JSON object with fields:
  • query
  • operationName (optional)
  • variables (optional)
• POST multipart parts named "query", "operationName" (optional), and "variables" (optional)

The simplest form of the servlet takes a graphql-java GraphQLSchema and an ExecutionStrategy:

GraphQLServlet servlet = new SimpleGraphQLServlet(schema, executionStrategy); // or GraphQLServlet servlet = new SimpleGraphQLServlet(schema, executionStrategy, operationListeners, servletListeners);

You can also add servlet listeners to an existing servlet. These listeners provide hooks into query execution (before, success, failure, and finally) and servlet execution (before, success, error, and finally):

servlet.addListener(new GraphQLServletListener() { @Override GraphQLServletListener.RequestCallback onRequest(HttpServletRequest request, HttpServletResponse response) { return new GraphQLServletListener.RequestCallback() { @Override void onSuccess(HttpServletRequest request, HttpServletResponse response) { } @Override void onError(HttpServletRequest request, HttpServletResponse response, Throwable throwable) { } @Override void onFinally(HttpServletRequest request, HttpServletResponse response) { } } } @Override GraphQLServletListener.OperationCallback onOperation(GraphQLContext context, String operationName, String query, Map<String, Object> variables) { return new GraphQLServletListener.OperationCallback() { @Override void onSuccess(GraphQLContext context, String operationName, String query, Map<String, Object> variables, Object data) { } @Override void onError(GraphQLContext context, String operationName, String query, Map<String, Object> variables, Object data, List<GraphQLError> errors) { } @Override void onFinally(GraphQLContext context, String operationName, String query, Map<String, Object> variables, Object data) { } } } })

Relay.js support is provided by the EnhancedExecutionStrategy of graphql-java-annotations. You MUST pass this execution strategy to the servlet for Relay.js support.

This is the default execution strategy for the OsgiGraphQLServlet, and must be added as a dependency when using that servlet.

Query batching is supported, no configuration required.

To use the servlet with Spring Framework, either use the Spring Boot starter or simply define a ServletRegistrationBean in a web app:

@Bean ServletRegistrationBean graphQLServletRegistrationBean(GraphQLSchema schema, ExecutionStrategy executionStrategy, List<GraphQLOperationListener> operationListeners) { return new ServletRegistrationBean(new SimpleGraphQLServlet(schema, executionStrategy, operationListeners), "/graphql"); }

The OsgiGraphQLServlet uses a "provider" model to supply the servlet with the required objects:

• GraphQLQueryProvider: Provides query fields to the GraphQL schema.
• GraphQLMutationProvider: Provides mutation fields to the GraphQL schema.
• GraphQLTypesProvider: Provides type information to the GraphQL schema.
• ExecutionStrategyProvider: Provides an execution strategy for running each query.
• GraphQLContextBuilder: Builds a context for running each query.

You can now find some example on how to use graphql-java-servlet.

The OSGi examples use Maven as a build tool because it requires plugins that are not (yet) available for Gradle. Therefore you will need Maven 3.2+.

You can build the OSGi examples sub-projects by simply executing the following command from the examples/osgi directory:

mvn clean install 

This will generate a complete Apache Karaf distribution in the following files:

 examples/osgi/apache-karaf-package/target/graphql-java-servlet-osgi-examples-apache-karaf-package-VERSION.tar.gz(.zip) 

You can simply uncompress this file and launch the OSGi server using the command from the uncompressed directory:

bin/karaf 

You should then be able to access the GraphQL endpoint at the following URL once the server is started:

http://localhost:8181/graphql/schema.json 

If you see the JSON result of an introspection query, then all is ok. If not, check the data/log/karaf.log file for any errors.

We also provide a script file to do all of the building and running at once (only for Linux / MacOS ):

./buildAndRun.sh 

You can use the graphql-java-servlet as part of an Apache Karaf feature, as you can see in the example project here:

• pom.xml

And here is a sample src/main/feature/feature.xml file to add some dependencies on other features:

• feature.xml

Here's an example of a GraphQL provider that implements three interfaces at the same time.

• ExampleGraphQLProvider