Are you ready to see GraphQL in action?

                      In the last article, we have discussed GraphQL advantages over REST. In this article, we will see GraphQL in action. I have created a sample application to showcase differences between REST and GraphQL. First, we will see the REST implementation of simple product detail endpoint. I have used Spring Boot to demonstrate REST. Download sample project and follow the steps outlined in README to set up the project. I am not discussing setup details here as it is out of scope for this article. Assuming that your project is up and running to make a call to http://localhost:8080/product/{product_id} endpoint to get product detail JSON as shown below.

If you observe above JSON, we are getting entire product JSON including reviews and technical specifications though we are not interested in all the elements of a given product.

                   Now we will see GraphQL in action by getting product details in a selective manner. To demonstrate GraphQL again I used Spring Boot. Download sample project and follow the steps outlined in README to set up the project. I am not discussing setup details here as it is out of scope for this article. Assuming that your project is up and running to see GraphQL in action. In this case, I am interested to get only product id, title, short description and list price of a given product. Let us see how we can query to get interesting details.

Now as a service consumer I am interested to get product id, title, short description, list price, and reviews. In this case, GraphQL gives the flexibility to query what we want. See below query and response when we use GraphQL.

To demonstrate GraphQL I have used GUI based plugin GraphiQL. For consuming from other applications we can configure endpoint in application.properties.

Now we can make a call to the above endpoint by passing  URL encoded query parameter as shown below. You can learn more about query and mutations https://graphql.org/learn/queries/

Hope you enjoyed this article. I will come back with another article. Till then, Happy Learning!!!

About Siva Prasad Rao Janapati

Siva Janapati is an Architect with experience in building Cloud Native Microservices architectures, Reactive Systems, Large scale distributed systems, and Serverless Systems. Siva has hands-on in architecture, design, and implementation of scalable systems using Cloud, Java, Go lang, Apache Kafka, Apache Solr, Spring, Spring Boot, Lightbend reactive tech stack, APIGEE edge & on-premise and other open-source, proprietary technologies. Expertise working with and building RESTful, GraphQL APIs. He has successfully delivered multiple applications in retail, telco, and financial services domains. He manages the GitHub(https://github.com/2013techsmarts) where he put the source code of his work related to his blog posts.