OpenAPI and Java - Portland - 2019-12-10

Transcript

1. OpenAPI and Java Sean Sullivan Portland Java User Group December

   10, 2019

2. About me software engineer Portland Oregon Java Scala

3. Agenda OpenAPI Real world examples Java tools and libraries API

   guidelines

4. OpenAPI

5. OpenAPI is a specification for describing API’s

6. API specifications

7. WSDL (SOAP) WADL (REST)

8. Swagger (REST) OpenAPI (REST)

9. https://en.wikipedia.org/wiki/OpenAPI_Specification

10. REST API’s

11. API Driven Development

12. “API first”

13. source: Adobe Tech Blog June 2017

14. Code first vs API schema first

15. JSON or YAML

16. Real world examples

17. Case Study: stripe.com OpenAPI

18. https://github.com/stripe/openapi

19. https://github.com/stripe/openapi

20. Case Study: squareup.com OpenAPI

21. https://github.com/square/connect-api-specification

22. Case Study: Kubernetes OpenAPI

23. https://github.com/kubernetes/kubernetes/tree/master/api/openapi-spec

24. https://github.com/kubernetes-client/java Kubernetes Java Client

25. https://github.com/kubernetes-client/java Kubernetes Java Client code generation

26. Case Study: Microsoft Azure OpenAPI

27. https://github.com/Azure/azure-rest-api-specs azure-rest-api-specs

28. Case Study: Amazon EventBridge OpenAPI

29. https://docs.aws.amazon.com/eventbridge Amazon EventBridge “EventBridge is a serverless event bus service

    that makes it easy to connect your applications with data from a variety of sources”

30. https://docs.aws.amazon.com/eventbridge EventBridge Schema Registry Schemas are defined using JSON files,

    using the OpenAPI specification

31. https://www.tbray.org/ongoing/When/201x/2019/12/02/Strongly-Typed-Events Strongly typed events

32. Java tools and libraries

33. Swagger libraries swagger-core swagger-parser swagger-codegen swagger-inflector

34. https://github.com/swagger-api/swagger-parser Swagger parser

35. pom.xml <dependency> <groupId>io.swagger.parser.v3</groupId> <artifactId>swagger-parser</artifactId> <version>2.0.16</version> </dependency> Swagger parser

36. https://github.com/swagger-api/swagger-parser import io.swagger.v3.parser.OpenAPIV3Parser; import io.swagger.v3.oas.models.OpenAPI; String url = “http://petstore.swagger.io/v3/openapi.json”; OpenAPI

    openAPI = new OpenAPIV3Parser().read(url); Swagger parser

37. https://github.com/swagger-api/swagger-parser Swagger parser Pull Request #1271

38. ObjectMapperFactory.java return new JsonFactoryBuilder() .enable(StreamReadFeature.STRICT_DUPLICATE_DETECTION) .build(); Swagger parser Pull Request

    #1271

39. Code generators Guardrail openapi-generator swagger-codegen AutoRest

40. Guardrail project

41. https://guardrail.dev/ Guardrail

42. https://github.com/twilio/guardrail Guardrail

43. https://github.com/twilio/guardrail Guardrail: Scala ScalaMeta

44. https://github.com/twilio/guardrail Guardrail: Java JavaParser

45. Guardrail example

46. guardrail-maven-plugin <plugin> <groupId>com.twilio</groupId> <artifactId>guardrail-maven-plugin_2.12</artifactId> <version>0.54.5</version> <executions> … </executions> </plugin>

47. guardrail-maven-plugin <configuration> <language>java</language> <kind>client</kind> <framework>dropwizard</framework> <specPath>${project.basedir}/src/main/openapi/petstore.json</specPath> <packageName>com.example.clients.petstore</packageName> </configuration> Java client

48. guardrail-maven-plugin

49. openapi-generator project

50. openapi-generator

51. openapi-generator

52. openapi-generator

53. REST API guidelines

54. https://github.com/microsoft/api-guidelines

55. https://www.infoq.com/news/2016/07/microsoft-rest-api/ July 2016

56. https://cloud.google.com/apis/design/

57. https://github.com/zalando/restful-api-guidelines

58. https://github.com/paypal/api-standards/blob/master/api-style-guide.md

59. Final thoughts use OpenAPI to define REST API’s adopt “API

    First” approach use a code generator to generate client libraries contribute to open source projects

60. The End