Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
OpenAPI and Java - Portland - 2019-12-10
Search
sullis
December 10, 2019
Programming
250
0
Share
OpenAPI and Java - Portland - 2019-12-10
Portland Java User Group
Portland Oregon
December 10, 2019
#openapi
#java
sullis
December 10, 2019
More Decks by sullis
See All by sullis
AI Assisted Software Development - Portland Java User Group - 2026-04-14
sullis
0
44
Dependency Management for Java - Seattle 2025-11-18
sullis
0
44
Dependency Management for Java - Portland - 2025-11-04
sullis
0
26
Dependency management for Java applications 2025-09-11
sullis
0
35
S3 NYC Iceberg meetup 2025-07-10
sullis
0
55
Amazon S3 Chicago 2025-06-04
sullis
0
130
Amazon S3 Boston 2025-05-07
sullis
0
100
Netty ConFoo Montreal 2025-02-27
sullis
0
160
GitHub Actions ConFoo Montreal 2025-02-26
sullis
0
100
Other Decks in Programming
See All in Programming
2026_04_15_量子計算をパズルとして解く
hideakitakechi
0
110
Claude Codeをカスタムして自分だけのClaude Codeを作ろう
terisuke
0
140
属人化しないコード品質の作り方_2026.04.07.pdf
muraaano
0
210
Programming with a DJ Controller — not vibe coding
m_seki
3
130
PDI: Como Alavancar Sua Carreira e Seu Negócio
marcelgsantos
0
120
アーキテクチャモダナイゼーションとは何か
nwiizo
19
5.3k
おれのAgentic Coding 2026/03
tsukasagr
1
150
mruby on C#: From VM Implementation to Game Scripting (RubyKaigi 2026)
hadashia
2
570
運転動画を検索可能にする〜Cosmos-Embed1とDatabricks Vector Searchで〜/cosmos-embed1-databricks-vector-search
studio_graph
0
340
ドメインイベントでビジネスロジックを解きほぐす #phpcon_odawara
kajitack
3
790
Surviving Black Friday: 329 billion requests with Falcon!
ioquatix
0
520
[RubyKaigi 2026] Require Hooks
palkan
1
210
Featured
See All Featured
GitHub's CSS Performance
jonrohan
1032
470k
Hiding What from Whom? A Critical Review of the History of Programming languages for Music
tomoyanonymous
2
770
30 Presentation Tips
portentint
PRO
1
280
Navigating the moral maze — ethical principles for Al-driven product design
skipperchong
2
340
A Soul's Torment
seathinner
6
2.7k
Dominate Local Search Results - an insider guide to GBP, reviews, and Local SEO
greggifford
PRO
0
140
Un-Boring Meetings
codingconduct
0
270
Building AI with AI
inesmontani
PRO
1
910
How People are Using Generative and Agentic AI to Supercharge Their Products, Projects, Services and Value Streams Today
helenjbeal
1
170
Large-scale JavaScript Application Architecture
addyosmani
515
110k
Why Your Marketing Sucks and What You Can Do About It - Sophie Logan
marketingsoph
0
130
Being A Developer After 40
akosma
91
590k
Transcript
OpenAPI and Java Sean Sullivan Portland Java User Group December
10, 2019
About me software engineer Portland Oregon Java Scala
Agenda OpenAPI Real world examples Java tools and libraries API
guidelines
OpenAPI
OpenAPI is a specification for describing API’s
API specifications
WSDL (SOAP) WADL (REST)
Swagger (REST) OpenAPI (REST)
https://en.wikipedia.org/wiki/OpenAPI_Specification
REST API’s
API Driven Development
“API first”
source: Adobe Tech Blog June 2017
Code first vs API schema first
JSON or YAML
Real world examples
Case Study: stripe.com OpenAPI
https://github.com/stripe/openapi
https://github.com/stripe/openapi
Case Study: squareup.com OpenAPI
https://github.com/square/connect-api-specification
Case Study: Kubernetes OpenAPI
https://github.com/kubernetes/kubernetes/tree/master/api/openapi-spec
https://github.com/kubernetes-client/java Kubernetes Java Client
https://github.com/kubernetes-client/java Kubernetes Java Client code generation
Case Study: Microsoft Azure OpenAPI
https://github.com/Azure/azure-rest-api-specs azure-rest-api-specs
Case Study: Amazon EventBridge OpenAPI
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”
https://docs.aws.amazon.com/eventbridge EventBridge Schema Registry Schemas are defined using JSON files,
using the OpenAPI specification
https://www.tbray.org/ongoing/When/201x/2019/12/02/Strongly-Typed-Events Strongly typed events
Java tools and libraries
Swagger libraries swagger-core swagger-parser swagger-codegen swagger-inflector
https://github.com/swagger-api/swagger-parser Swagger parser
pom.xml <dependency> <groupId>io.swagger.parser.v3</groupId> <artifactId>swagger-parser</artifactId> <version>2.0.16</version> </dependency> Swagger parser
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
https://github.com/swagger-api/swagger-parser Swagger parser Pull Request #1271
ObjectMapperFactory.java return new JsonFactoryBuilder() .enable(StreamReadFeature.STRICT_DUPLICATE_DETECTION) .build(); Swagger parser Pull Request
#1271
Code generators Guardrail openapi-generator swagger-codegen AutoRest
Guardrail project
https://guardrail.dev/ Guardrail
https://github.com/twilio/guardrail Guardrail
https://github.com/twilio/guardrail Guardrail: Scala ScalaMeta
https://github.com/twilio/guardrail Guardrail: Java JavaParser
Guardrail example
guardrail-maven-plugin <plugin> <groupId>com.twilio</groupId> <artifactId>guardrail-maven-plugin_2.12</artifactId> <version>0.54.5</version> <executions> … </executions> </plugin>
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
guardrail-maven-plugin
openapi-generator project
openapi-generator
openapi-generator
openapi-generator
REST API guidelines
https://github.com/microsoft/api-guidelines
https://www.infoq.com/news/2016/07/microsoft-rest-api/ July 2016
https://cloud.google.com/apis/design/
https://github.com/zalando/restful-api-guidelines
https://github.com/paypal/api-standards/blob/master/api-style-guide.md
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
The End