Introduction to MVC 1.0

Transcription

1 Introduction to MVC 1.0 David Delabassee Software Evangelist Cloud & Microservices - Oracle Java Day Tokyo 2016 May 24, 2016 Copyright 2016, Oracle and/or its its affiliates. All All rights reserved. 1

2 Safe Harbor Statement The following is intended to outline our g eneral product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle s products remains at the sole discretion of Oracle. 2

3 Personal Statement Lorem ipsum dolor sit amet, MVC, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua, Action- Based MVC. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. JSR 371 duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Ozark excepteur sint occaecat cupidatat non proident. 3

4 Agenda Context MVC 1.0 JSR Conclusion 4

5 Agenda Context MVC 1.0 JSR Conclusion 5

6 What is MVC? Pattern used to implement a User Interface Consists of 3 major components Model View Controller Each of the components has a distinct responsibility 6

7 Model View Controller Request Controller Update Update Model Get View 7

8 The M(odel) Interim state you want to keep when you are building an UI Examples Who is logged in What are they trying to buy What page are they on in a multi page flow 8

9 The V(iew) What your user interacts with In a web application that would be the web page or web pages your JSP page your CSS styles your JavaScript In a thick client scenario it would be the entire UI In an embedded scenario it could be the touch screen, hardware buttons etc. 9

10 The C(ontroller) Work horse of the pattern: Executes the business logic Run a credit card transaction Updates the model Mark the transaction as successful in the model object Ask the view to render itself Shows the transaction was successful 10

11 Different styles of MVC Component- based MVC Action- based MVC Others 11

12 Component- based MVC Specific style of MVC made popular by component frameworks JavaServer Faces Wicket Tapestry Seam (discontinued), Apache Click (retired) Controller Request Controller provided by the framework Update Update Model View Get 12

13 Action- based MVC Controller(s) defined by the application Struts 1 (EoL), Struts 2 Spring MVC Request Controller Update Update Model Get View 13

14 Compare and contrast Action- based MVC Component- based MVC Manual request parameter processing No view kept around Request centric Developer responsible for all HTML / JS Limited support for re- usable behavior No automatic input conversion No automatic input validation Automatic request parameter processing View kept around Page centric Components handle HTML / JS Component implement re- usable behavior Automatic input conversion Automatic input validation 14

15 Java EE 7 DEVELOPER PRODUCTIVITY ENTERPRISE EDITION MEETING ENTERPRISE DEMANDS Java EE 7 More annotated POJOs Less boilerplate code Cohesive integrated platform WebSockets JSON Servlet 3.1 NIO REST Batch Concurrency Simplified JMS 15

16 Agenda Context MVC 1.0 JSR Conclusion 16

17 Model- View- Controller (MVC 1.0) Specification JSR 371 Action- based MVC 1.0 JSR Why? UI landscape is not one size fits all Talking to our customers, etc. EG Oracle, RedHat, innoq, IBM, Caelum, LifeRay, and individuals members 17

18 Model- View- Controller (MVC 1.0) Specification Reference Implementation Ozark Open Source git://java.net/ozark~sources 18

19 MVC 1.0 Action- based MVC Glues together key Java EE technologies Model - CDI, Bean Validation, JPA View - Facelets, JSP, more? Controller - Invent new technology Vs. Leverage existing technologies 19

20 Controller Combine data models and views to produce web application public class HelloController public String hello() { return "hello.xhtml"; } 20

21 Controller Class/method public class HelloController hello.xhtml") public void hello() { } 21

22 Controller public class HelloController { public Viewable hello() { return new Viewable("hello.jsp"); } 22

23 Controller public Response String id) { if (id.length() == 0) { return Response.status(Response.Status.BAD_REQUEST).entity("error.xhtml").build(); } } 23

24 Model Refers to the data javax.mvc.models interface bean (recommended) 24

25 Model public class Greeting { } private String message; public String getmessage() { return message; } public void setmessage(string message) { this.message = message; } 25

26 public class HelloController { private public String hello() { models.put("greeting", new Greeting("Hi Tokyo!")); return "hello.ftl"; } 26

27 View Define the structure of the output Can refer to model(s) Rendered by a View Engine JSP Facelets Not accessible as static resources /WEB- INF/views/ 27

28 View <?xml version='1.0' encoding='utf-8'?> <!DOCTYPE html PUBLIC > <html xmlns=" xmlns:h=" <h:head> <title>facelet!</title> </h:head> <h:body> <p>${greeting.message} to all</p> </h:body> </html> 28

29 View page contenttype= text/html;charset=utf-8 language= java %> <html> <head> <title>hello</title> </head> <body> <p>${greeting.message}</p> </body> </html> 29

30 View Engine CDI based extension mechanism javax.mvc.engine.viewengine interface boolean supports(string view); void processview(viewenginecontext context) Ozark JSP & Facelets throws ViewEngineException; FreeMarker, Velocity, Thymeleaf, Mustache, AsciiDoc, Handlebars, 30

31 Exception Handling Exception Mapping Providers Based on JAX- RS Convert exception(s) to response(s) Controller may also act as Exception Handler Via javax.mvc.validation.validationresult property Controller methods called even if a validation error is encountered 31

32 Miscellaneous Bootstrap javax.ws.rs.core.application Validation Exception Mapping CDI Events Tooling 32

33 Agenda Context MVC 1.0 JSR Conclusion 33

34 Conclusion Doing MVC now is not a bad idea, because we are: Leveraging CDI, JAX- RS, Facelets, BV More? Delivering an easy migration path if you are using JSPs Offers more choices 34

35 Contribute! Get involved Join MVC users mailing list Tweet, blog, socialize to raise awareness about MVC 1.0 Test MVC SNAPSHOT and milestone builds ( Fill issues! 35

36 Links MVC specification spec.java.net, spec.java.net MVC implementation The Aquarium Blog 36

37 **!! Mnogo blagodaria! Copyright 2016, Copyright* *2016,*Oracle*and/or*its*affiliates.*All*rights*reserved.** * and/or its affiliates. rights reserved. 37

38 Copyright 2015, Oracle and/or its affiliates. All rights reserved. 38