GraphQL with Spring Boot

Slides from my presentation @ CareerCon Kariera IT Gdańsk (18.11.2017)

Transcript

1. GraphQL with Spring Boot 18.11.2017 Krzysztof Pawłowski krzysztof.pawlowski@merapar.com | krzychpawlowski
2. About me • Senior Java Developer @ Merapar Technologies • Coder, Lecturer (PJATK), Java Trainer (iSA) • 7+ years of experience in Java Development • using GraphQL for a year now • E-mail: krzysztof.pawlowski@merapar.com • Twitter: krzychpawlowski
3. REST not so restful? GET /author/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment
4. REST not so restful? GET /author/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment {
 id: 1,
 name: “Krzysztof”,
 email:”k@example.com“,
 bio: “java dev”, blogEntriesIds: [1, 2]
 }
5. REST not so restful? GET /author/:id GET /author/:id/blogEntry/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment
6. REST not so restful? GET /author/:id GET /author/:id/blogEntry/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment {
 id: 1, title: “GraphQL”,
 authorId: 1, commentsIds: [1, 2]
 }
7. REST not so restful? GET /author/:id/blogEntry/:id/comments GET /author/:id GET /author/:id/blogEntry/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment
8. REST not so restful? GET /author/:id/blogEntry/:id/comments GET /author/:id GET /author/:id/blogEntry/:id <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment {
 id: 1,
 author: “anonymous”,
 comment: “super!”
 }
9. While in GraphQL… authors(filter : {id : 1 }) {
 name
 blogEntry {
 title
 comment {
 comment
 }
 }
 } <<class>>
 Author Long id String name String email String bio List<BlogEntry>
 blogEntries <<class>>
 BlogEntry Long id String title List<Comment> comments <<class>>
 Comment Long id String author String comment
10. What is GraphQL? “GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data.” — http://graphql.org
11. What is GraphQL? “GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data.” — http://graphql.org Declarative
 Ask for what you need, get exactly that
12. What is GraphQL? “GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data.” — http://graphql.org Declarative
 Ask for what you need, get exactly that Compositional
 Get many resources in a single request
13. What is GraphQL? “GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data.” — http://graphql.org Declarative
 Ask for what you need, get exactly that Compositional
 Get many resources in a single request Strongly Typed
 Describe what’s possible with a type system
14. GraphQL query authors { # queries can have comments! name email blogEntries { title } }
15. GraphQL query authors { # queries can have comments! name email blogEntries { title } } { "data": { "authors": [ { "name": "author 1", "email": "Python dev", "blogEntries": [ { "title": "blog entry 1" }, { "title": "blog entry 3" } ] }, { "name": "author 2", "email": "Java dev", "blogEntries": [ { "title": "blog entry 2" }, { "title": "blog entry 4" } ] } ] }
16. GraphQL query - filter authors(filter : {id : 1 }) { name email blogEntries { title } }
17. GraphQL query - filter authors(filter : {id : 1 }) { name email blogEntries { title } } { "data": { "authors": [ { "name": "author 1", "email": "Python dev", "blogEntries": [ { "title": "blog entry 1" }, { "title": "blog entry 3" } ] } ] } }
18. GraphQL mutation mutation addAuthorMutation($authorInfo: addAuthorInput!) { addAuthor(input : $authorInfo) { id name bio email } } { "authorInfo": { "id": 1, “name" : "Krzysztof Pawlowski", "bio" : "java dev", "email" : "krzysztof.pawlowski@merapar.com" }
19. GraphQL mutation mutation addAuthorMutation($authorInfo: addAuthorInput!) { addAuthor(input : $authorInfo) { id name bio email } } { "authorInfo": { "id": 1, “name" : "Krzysztof Pawlowski", "bio" : "java dev", "email" : "krzysztof.pawlowski@merapar.com" } { "data": { "addAuthor": { "id": 1, "name": "Krzysztof Pawlowski", "bio": "java dev", "email": 
 “krzysztof.pawlowski@merapar.com" } } }
20. GraphQL schema type Author {
 id: Long! name: String bio: String email: String
 blogEntries: [BlogEntry] }
 
 type BlogEntry { id: Long! title: String! comments: [Comment] } type Comment { id: Long! author: String comment: String }

21. GraphQL schema type Author {
 id: Long! name: String bio: String email: String
 blogEntries: [BlogEntry] }
 
 type BlogEntry { id: Long! title: String! comments: [Comment] } type Comment { id: Long! author: String comment: String }
 type Query { authors(id: Long!): Author blogEntries(id: Long!): BlogEntry comments(id: Long!): Comment } type Mutation { addAuthor(author: Author!): Author updateAuthor(author: Author!): Author deleteAuthor(author: Author!): Author … }
22. GraphQL schema type Author {
 id: Long! name: String bio: String email: String
 blogEntries: [BlogEntry] }
 
 type BlogEntry { id: Long! title: String! comments: [Comment] } type Comment { id: Long! author: String comment: String }
 type Query { authors(id: Long!): Author blogEntries(id: Long!): BlogEntry comments(id: Long!): Comment } type Mutation { addAuthor(author: Author!): Author updateAuthor(author: Author!): Author deleteAuthor(author: Author!): Author … } schema { query: Query mutation: Mutation }
23. Other benefits of GraphQL ‣flexibility ‣one end-point ‣self-documenting (strong typing and schema) ‣query validation ‣no versioning needed
24. Client and documentation
25. Spring Boot Starter for GraphQL ‣adding Maven dependency creates GraphQL controller under
 /v1/graphql <dependency> <groupId>com.merapar</groupId> <artifactId>graphql-spring-boot-starter</artifactId> <version>1.0.2</version> </dependency> ‣adding new queries and mutation is a matter of implementing GraphQlFields interface
26. Demo https://github.com/krzysztof-pawlowski/GraphQLwithSpringBoot
27. Problems with GraphQL ‣HTTP caching ‣Unpredictable execution ‣No handling for file upload ‣Authorisation and authentication
28. Thank you! Questions? krzysztof.pawlowski@merapar.com | krzychpawlowski
29. Bonus — GitHub GraphQL API https://developer.github.com/v4/