Java REST client with Feign

Talk at DevFest Toulouse (03 Nov 2016)

Transcript

1. #DevFestToulouse #Feign @ilaborie Java REST client wi Connected to BrowserSync
2. ď whoami Igor Laborie Expert Java & Web,  @ilaborie  igor@monkeypatch.io #DevFestToulouse #Feign @ilaborie 2 Connected to BrowserSync
3. Roadmap 1. Basic Đ CRUD operations, JSON 2. Advanced Đ Async with RxJava Đ Circuit Breaker with Hystrix Đ HTTP/2 with Java 9 #DevFestToulouse #Feign @ilaborie 3 Connected to BrowserSync
4. Basic #DevFestToulouse #Feign @ilaborie 4 Connected to BrowserSync
5. ď whois feign Ÿ https://github.com/OpenFeign/feign Open Source: license Apache 2.0 A Netflix Project Java 7+, Java 8 friendly Not opinionated #DevFestToulouse #Feign @ilaborie 5 Connected to BrowserSync
6. ď du -h target/*.jar Classes Fat jar Jersey (JAX-RS 2) 112 4,6 Mo Retrofit 2 38 740 Ko Feign 34 336 Ko *: only into javax.ws.rs Ÿ See code on github #DevFestToulouse #Feign @ilaborie * 6 Connected to BrowserSync
7. Most Java applications require a persistent class representing felines. Hibernate Documentation ... #DevFestToulouse #Feign @ilaborie “ 7 Connected to BrowserSync
8. Most Java applications require a microservice for felines. Any buzzword addicts #DevFestToulouse #Feign @ilaborie “ 8 Connected to BrowserSync
9. ď curl http://cats/swagger Run with: docker run -p 8080:8080 ilaborie/cats-microservice Ÿ See code on github #DevFestToulouse #Feign @ilaborie 9 Connected to BrowserSync
10. Đ Live coding CRUD operations, JSON Ÿ See code on github #DevFestToulouse #Feign @ilaborie 10 Connected to BrowserSync
11. Encoders & Decoders • JSON with GSON: feign-gson or Jackson: feign-jackson • XML with JAXB: feign-jaxb , Jackson JAXB: jackson-jaxb or SAX: feign-sax (decoder only) #DevFestToulouse #Feign @ilaborie 11 Connected to BrowserSync
12. Under the hood Ä No White/Dark Magic The java.lang.re ect.Proxy allow you to dynamically implement the interface. Use the java.net.HttpURLConnection to send and process HTTP requests. (by default) Use the reflection API to extract meta-data. If you prefer JAX-RS annotation you can use feign-jaxrs . #DevFestToulouse #Feign @ilaborie 12 Connected to BrowserSync
13. Advanced #DevFestToulouse #Feign @ilaborie 13 Connected to BrowserSync
14. How to be async ? Do not write a custom feign.Decoder ! You can use Java 8 CompletableFuture Or the feign-hystrix provide RxJava support #DevFestToulouse #Feign @ilaborie 14 Connected to BrowserSync
15. Đ Live coding Async with Ÿ See code on github #DevFestToulouse #Feign @ilaborie 15 Connected to BrowserSync
16. Circuit Breaker By Bidgee (Own work) CC BY-SA 3.0, via Wikimedia Commons #DevFestToulouse #Feign @ilaborie 16 Connected to BrowserSync
17. Đ Live coding Circuit Breaker with Ÿ See code on github #DevFestToulouse #Feign @ilaborie 17 Connected to BrowserSync
18. Incoming train .... % Download Java 9 Early Access Can be downloaded with/without Jigsaw Or use docker: docker run openjdk:9 java -version docker run maven:3-jdk-9 mvn -version #DevFestToulouse #Feign @ilaborie 18 Connected to BrowserSync
19. JEP 110: HTTP/2 Client 7 java.net.http URI uri = new URI("http://127.0.0.1:8080/hello") HttpResponse resp = HttpRequest.create(uri) .GET().response(); int statusCode = resp.statusCode(); String body = resp.body(HttpResponse.asString()); System.out.printf("[%s] %s\n", statusCode, body); #DevFestToulouse #Feign @ilaborie 01. 02. 03. 04. 05. 06. 19 Connected to BrowserSync
20. Đ Live coding Custom feign.Client with Ÿ See code on github #DevFestToulouse #Feign @ilaborie 20 Connected to BrowserSync
21. feign.Client implementation • Apache HttpClient: feign-httpclient • OkHttp: feign-okhttp HTTP/2 & caching support • Ribbon: feign-ribbon Load balancing support #DevFestToulouse #Feign @ilaborie 21 Connected to BrowserSync
22. So why feign: Open & active community Simple & intuitive Extensible, useful plugins, easy to write your own Not opinionated #DevFestToulouse #Feign @ilaborie 22 Connected to BrowserSync
23. Any Question ? #DevFestToulouse #Feign @ilaborie 23 Connected to BrowserSync
24. http://bit.ly/devfest-feign #DevFestToulouse #Feign @ilaborie 24 Connected to BrowserSync