GraphQL-ify your APIs - Devoxx UK 2021
- 1. GraphQL-ify your APIs Soham Dasgupta
- 2. Soham Dasgupta • Father, Husband and Football lover • Capgemini Netherlands • Oracle ACE • Tech Enthusiast/Programmer/Architect • Speaker & Blogger • Twitter : @iamsoham • LinkedIn: dasguptasoham • Github: sohamda • Medium: @iam.soham Who am I?
- 3. What’s in store today GraphQL What Queries & Mutation Schemas & Types Show me some code graphql-java graphql-java-kickstart graphql-dgs-framework What’s better Implementation easiness – code, generation, error handling, testing, clients N+1 problem Memory footprint
- 4. GraphQL is a query language for your API, and a server-side runtime for executing queries. Backed by your existing code and data. It was designed by Facebook to get around common constraints in fetching data via REST. It was open sourced by Facebook in 2015. Nothing to do with Graph DB. Not a replacement of REST. Not going to magically solve every API design issues. What’s GraphQL
- 5. Schema Query Results Schema , Query & Results GraphQL provides description of the data in your API, gives clients the power to ask for exactly what they need.
- 7. GraphQL vs REST API vs SOAP https://trends.google.com/trends/explore?date=today%205-y&q=%2Fg%2F11cn3w0w9t,REST%20API,%2Fm%2F077dn
- 8. Hierarchical & Aggregator Strongly Typed Validation & Type check out-of-the-box API evolution without versioning GraphQL Characteristics
- 9. Query & Mutation • Ask what you need. • Expand the same query. • Send arguments. • Use Aliases, Fragment Schemas & Types • GraphQL schema language - allows us to talk about GraphQL schemas in a language-agnostic way. • Scalar : Int, String, Boolean, ID, Float • Lists & Non-Null • Union, Interfaces, Input Types
- 10. N+1 queries Caching complexity Community presence File Upload GraphQL Maturity
- 11. Show me some code graphql-java graphql-java-kickstart graphql-dgs-framework
- 13. graphql-java https://www.graphql-java.com/documentation/v17/ https://github.com/graphql-java - Version 17.3 : Last updated on Sep’21 https://github.com/graphql-java/graphql-java-spring
- 15. graphql-java- kickstart https://graphql-java-kickstart.com/ https://github.com/graphql-java-kickstart Version 12 : Last updated on Sep’21
- 17. dgs-framework https://netflix.github.io/dgs/ https://github.com/Netflix/dgs-framework Version 4.9.2 : Last updated on Oct’21
- 19. What’s better Implementation easiness – code, generation, error handling, testing, clients N+1 problem Memory footprint
- 20. DataFetchers graphql-java Piece of code that fetches the data graphql-java-kickstart dgs 1. Define a @Component which defines datafetching methods. 2. Register them in while building/parsing the schema 1. Define @Component which implements GraphQLQueryResolver. 2. For field-level define a @Component which implements GraphQLResolver<T>. 1. Define a @DgsComponent. 2. Map the schema operations with @DgsData
- 21. DataLoaders graphql-java Piece of code that is responsible for N+1 query issue graphql-java-kickstart dgs 1. Define a BatchLoader which return s a CompletableFuture. 2. Define a DataLoaderRegistry @Bean which registers the Loader. 3. Define a DataFetcher using that Loader. 1. Define @Component which defines a loader and adds it to the registry. 2. Define a @Component which implements GraphQLServletContextBuild er and associate the registry. 1. Define a @DgsDataLoader. 2. Map the schema operations with @DgsData
- 22. Mutations graphql-java Piece of code that persist the data graphql-java-kickstart dgs 1. Define a @Component which defines datafetching methods. 2. Register them in while building/parsing the schema • Define @Component which implements GraphQLMutationResolver. 1. Define a @DgsComponent. 2. Map the schema operations with @DgsData
- 23. Error Handling graphql-java Piece of code that handles exceptions/errors graphql-java-kickstart dgs Implement GraphQLError 1. Enable ExceptionHandler property and handle them in a Spring way. 2. Implement GraphQLErrorHandler and manage the errors in overridden method. Define a @Component which implements DataFetcherExceptionHandle r
- 24. Client graphql-java How to call a GraphQL API graphql-java-kickstart dgs 1. No defined way. 2. Needs text templates to generate requests. 1. Gives a Webclient library. 2. Needs text templates to generate requests. 1. GraphQLClient uses String as query which is same as the previous two. 2. Code generation using Gradle/Maven. This is the type- safe option.
- 25. Testing graphql-java How to test your code graphql-java-kickstart dgs 1. No defined way. 2. Only can test the service-repo layer. 1. No defined way. 2. Only can test the service-repo layer. 1. Code generation using Gradle. This is the type-safe option. 2. Use the generated classes to build request and test using DgsAutoConfiguration class. graphql-java graphql-java-kickstart dgs 1. No defined way. 1. No defined way. 1. Code generation using Gradle/Maven. Code Generation
- 26. Runtime memory & Image Size
- 27. Final Words graphql-java graphql-java-kickstart dgs-framework • Is there since long, so evolved and matured. • A lot of Boilerplate code just to write a simple API. • Need extra library to work in Springboot. With other Java • Not a easy way to Unit Test everything you write. • No Clients avaiable. Need to use text templates to create queries. • Looks very matured but missing extended documentation. • Still a bit of Boilerplate code. • Directly usable within Springboot. Although other modules available to work on Java only environments. • Not a easy way to UT everything you write. • Basic Client avaiable. • Not sure about maturity, but Netflix is behind this, so faith is there. • No Boilerplate code. • Directly usable within Springboot. • You can UT everything you write. • Client avaiable. • Code generation using Gradle/Maven. https://medium.com/springboot-chronicles/graphql-in-springboot-a-comparative-study- among-the-libraries-and-their-implementation-know-how-b0e8d544f2fc
- 28. This presentation contains information that may be privileged or confidential and is the property of the Capgemini Group. Copyright © 2021 Capgemini. All rights reserved. Capgemini is a global leader in partnering with companies to transform and manage their business by harnessing the power of technology. The Group is guided everyday by its purpose of unleashing human energy through technology for an inclusive and sustainable future. It is a responsible and diverse organization of 270,000 team members in nearly 50 countries. With its strong 50 year heritage and deep industry expertise, Capgemini is trusted by its clients to address the entire breadth of their business needs, from strategy and design to operations, fuelled by the fast evolving and innovative world of cloud, data, AI, connectivity, software, digital engineering and platforms. The Group reported in 2020 global revenues of €16 billion. About Capgemini Get the Future You Want | www.capgemini.com