Questioning the status quo

A talk about the current state of java enterprise development, evaluation of the available alternatives to conventional enterprise solutions, tools and languages for the JVM, and possibly beyond.

JUG-Roma meeting 16 Sept 2014

Transcript

1. QUESTIONING THE STATUS QUO (THROUGH THE LOOKING GLASS) OF JAVA, OOP AND BEYOND
2. WHO AM I? A software developer just like you ... probably less smart than you, actually By the way let's see who we are
3. WHAT WILL YOU GET OUT OF THIS TALK?
4. What will you get out of this talk? image © collien SOME FOOD FOR THOUGHT AND BRAIN TEASING
5. What will you get out of this talk? A PRETTY COOL LIST OF FUTURE READINGS & VIDEOS
6. What will you get out of this talk? THINGS YOU DIDN'T KNOW THINGS YOU ALREADY KNEW THINGS YOU DIDN'T CARE TO KNOW
7. What will you get out of this talk? EXTRA UNSOLICITED SCALA AND FP PROMOTION!
8. LET'S START OUR JOURNEY FROM THE BEGINNING image © Justin Overell
9. Think about your first steps in programming...
10. You probably felt excited, curious and every bit of script that worked was so satisfying!
11. Even if you've been forced to learn programming as schoolwork, you probably got addicted to it sooner or later ...otherwise you wouldn't be here today, listening to this talk
12. It can happen though, that such passion fades in the background, trampled by daily chores
13. We should strive to try and keep caring for what we do, and keep alive that initial spark of passion for this activity
14. “AS DEVELOPERS, AS AN INDUSTRY, WE HAVE THE POTENTIAL TO CREATE A BETTER SOCIETY” Hadi Hariri from jetbrains - Codemotion Rome 2014 slides available here www.slideshare.net/Codemotion/developing-in-a-decade Do you still care?
15. WHERE DID I GET LOST?
16. A DAILY ROUTINE MESSY ENTERPRISEY CODE BUGS, CODE SMELLS, OVER- COMPLEXITY, IMPERFECTIONS SOPHISTICATED SOLUTIONS TO PROBLEMS... ... NEEDED TO SOLVE THE INDUSTRY NEEDS LIKE FASTER TIME TO MARKET AND TIGHT DELIVERY SCHEDULES
17. THE ENTIRE AGILE MOVEMENT WAS BORN TO ADAPT TO AND HANDLE THIS KIND OF ISSUES As a personal note, I recommend to take a look at the idea underlying agile, forgetting about costly certifications and easy promises
18. Let's take a look at some code
19. code @Controller @RequestMapping("/orders/{id}") @ExposesResourceFor(Payment.class) @RequiredArgsConstructor(onConstructor = @__(@Autowired)) public class PaymentController { private final @NonNull PaymentService paymentService; private final @NonNull EntityLinks entityLinks; /** * Accepts a payment for an {@link Order} */ @RequestMapping(value = PaymentLinks.PAYMENT, method = PUT) ResponseEntity<PaymentResource> submitPayment( @PathVariable("id") Order order, @RequestBody CreditCardNumber number) { if (order == null || order.isPaid()) { return new ResponseEntity<PaymentResource>(HttpStatus.NOT_FOUND); } CreditCardPayment payment = paymentService.pay(order, number); PaymentResource resource = new PaymentResource(order.getPrice(), payment.getCreditCard()); resource.add(entityLinks.linkToSingleResource(order)); return new ResponseEntity<PaymentResource>(resource, HttpStatus.CREATED); } source from https://github.com/olivergierke/spring-restbucks
20. code /** * Base class for entity implementations. Uses a {@link Long} id. */ @MappedSuperclass @Getter @ToString @EqualsAndHashCode public class AbstractEntity implements Identifiable<Long> { @Id @GeneratedValue(strategy = GenerationType.AUTO) @JsonIgnore private final Long id; protected AbstractEntity() { this.id = null; } } source from https://github.com/olivergierke/spring-restbucks pretty terse... uh?
21. Annotatiomania @Entity @Table(name = "Person", catalog = "TestDB", schema = "dbo") @XmlRootElement @NamedQueries({ @NamedQuery( name = "Person.findAll", query = "SELECT p FROM Person p"), @NamedQuery( name = "Person.findByPersonId", query = "SELECT p FROM Person p WHERE p.personId = :pId"), @NamedQuery( name = "Person.findByPersonName", query = "SELECT p FROM Person p WHERE p.personName = :pName"), @NamedQuery( name = "Person.findByPersonFamily", query = "SELECT p FROM Person p WHERE p.personFamily = :pFamily"), @NamedQuery( name = "Person.findByPersonReference", query = "SELECT p FROM Person p WHERE p.personReference = :pRef")}) public class Person implements Serializable { private static final long serialVersionUID = 1L; @Id @Basic(optional = false) @NotNull @Column(name = "person_id", nullable = false) private Integer personId; @Size(max = 50) @Column(name = "person_name", length = 50) source from https://groups.google.com/forum/#!topic/querydsl/4lgLx3QQqBA
22. root-context.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> <import resource="db-context.xml"/> <!-- Detects annotations like @Component, @Service, @Controller, @Repository, @Configuration --> <context:component-scan base-package="xpadro.spring.web,controller,xpadro.spring.web.service"/> <!-- Detects MVC annotations like @RequestMapping --> <mvc:annotation-driven/> </beans> source from https://github.com/xpadro/spring-rest
23. pom.xml <?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8" standalone="no"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.springsource.restbucks</groupId> <artifactId>restbucks</artifactId> <packaging>war</packaging> <version>1.0.0.BUILD-SNAPSHOT</version> <name>Spring RESTBucks</name> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.1.4.RELEASE</version> </parent> <properties> <spring-data-releasetrain.version>Evans-BUILD-SNAPSHOT</spring-data-releasetrain.version> <spring-hateoas.version>0.15.0.RELEASE</spring-hateoas.version> <tomcat.version>8.0.9</tomcat.version> </properties> <dependencies> <!-- Spring Data REST --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-rest</artifactId> </dependency> source from https://github.com/olivergierke/spring-restbucks still there? well, this can get pretty verbose
24. can get hard to decode .486P CR0_CD equ 040000000h ; Cache Disable bit of CR0 CR0_NW equ 020000000h ; Not Write-through bit of CR0 DisableCache proc pushf ; save the flags push eax ; save eax cli ; disable interrupts while we do this mov eax,cr0 ; read CR0 or eax,CR0_CD ; set CD but not NW bit of CR0 mov cr0,eax ; cache is now disabled wbinvd ; flush and invalidate cache ; the cache is effectively disabled at this point, but memory ; consistency will be maintained. To completely disable cache, ; the following two lines may used as well: or eax,CR0_NW ; now set the NW bit mov cr0,eax ; turn off the cache entirely pop eax ; restore eax popf ; restore the flags ret ; return to caller DisableCache endp code ends end
26. "Traditional" enterprise code today looks just like that
27. DO WE DARE AND TRY SOMETHING DIFFERENT? image © Elena Kalis
28. code public class Application extends Controller { /** Display the login page or dashboard if connected */ public static Result index() { String email = ctx().session().get("email"); if (email != null) { User user = User.findByEmail(email); if (user != null && user.validated) { return GO_DASHBOARD; } else { Logger.debug("Clearing invalid session credentials"); session().clear(); } } return ok(index.render(form(Register.class), form(Login.class))); } source from https://github.com/yesnault/PlayStartApp
29. code public String validate() { User user = null; try { user = User.authenticate(email, password); } catch (AppException e) { return Messages.get("error.technical"); } if (user == null) { return Messages.get("invalid.user.or.password"); } else if (!user.validated) { return Messages.get("account.not.validated.check.mail"); } return null; } source from https://github.com/yesnault/PlayStartApp
30. application.conf # This is the main configuration file for the application. # ~~~~~ # Secret key # ~~~~~ # The secret key is used to secure cryptographics functions. # If you deploy your application to several instances be sure to use the same key! application.secret="..." # Global object # ~~~~~ # Define the Global object type for this application. # Default to Global in the root package. # global=Global # Database configuration # ~~~~~ # You can declare as many datasources as you want. # By convention, the default datasource is named `default` # db.default.driver=org.h2.Driver db.default.url="jdbc:h2:mem:play" # # You can expose this datasource via JNDI if needed (Useful for JPA) # db.default.jndiName=DefaultDS # Evolutions # ~~~~~ # You can disable evolutions if needed # evolutions=disabled source from https://github.com/yesnault/PlayStartApp
31. routes.conf # Home page GET / controllers.Application.index() GET /dashboard controllers.Dashboard.index() POST /login controllers.Application.authenticate() GET /logout controllers.Application.logout() GET /settings controllers.account.settings.Index.index() GET /settings/password controllers.account.settings.Password.index() POST /settings/password controllers.account.settings.Password.runPassword() GET /settings/email controllers.account.settings.Email.index() POST /settings/email controllers.account.settings.Email.runEmail() ... source from https://github.com/yesnault/PlayStartApp
32. build.sbt import sbt.Keys._ name := "PlayStartApp" version := "1.0-SNAPSHOT" scalaVersion := "2.10.4" libraryDependencies ++= Seq( jdbc, javaEbean, cache, "org.mindrot" % "jbcrypt" % "0.3m", "com.typesafe" %% "play-plugins-mailer" % "2.2.0", filters ) resolvers ++= Seq( "Apache" at "http://repo1.maven.org/maven2/", "jBCrypt Repository" at "http://repo1.maven.org/maven2/org/", "Sonatype OSS Snasphots" at "http://oss.sonatype.org/content/repositories/snapshots" ) lazy val root = (project in file(".")).enablePlugins(play.PlayJava) source from https://github.com/yesnault/PlayStartApp It's all here folks
33. WHAT AM I TRYING TO SAY? It's too easy to get lost in cluttered technicalities Complex environments can blur the overall picture Every so often it's good to critically examine the tools we use Moreso if they result from some predetermined policy Find some time to explore new opportunities, they don't always pay back, but sometimes they do Don't be scared by the learning curve, you've been there already!
34. ABOUT THE "LEARNING CURVE" Rich Hickey (clojure, datomic) made interesting remarks about the different meaning of simple and easy presentation available here www.infoq.com/presentations/Simple-Made-Easy-QCon-London-2012
35. HAMMOCK DRIVEN DEVELOPMENT Hickey also discussed about the creative process and problem solving
36. HAMMOCK DRIVEN DEVELOPMENT About how solutions from related or unrelated fields can inspire new perspectives
37. HAMMOCK DRIVEN DEVELOPMENT About the need to focus
38. HAMMOCK DRIVEN DEVELOPMENT presentation available here https://www.youtube.com/watch?v=f84n5oFoZBc
39. QUIZ TIME
40. In “The Art of Agile Development” the author explores the concept that source code is actually the real software design He supports the concept with an example showing how modern structured programming conveys the program flow much better than Assembly code 1000 NS% = (80 - LEN(T$)) / 2 1010 S$ 0= "" 1020 IF NS$ = 0 GOTO 1060 1030 S$ = S$ + " " 1040 NS% = NS$ - 1 1050 GOTO 1020 1060 PRINT S$ + T$ 1070 RETURN So much that we seldom need flow diagrams anymore
41. Can you make out what both of these functions do? def version1(text: String) { val center = (LENGTH - text.size) / 2 var space = "" for (i <- 0 until center) { space += " " } println(space + text + space) } def version2(text: String) = { def recurse(space: String): String = if ((space*2 + text).size == LENGTH) space + text + space else recurse(space + " ") println(recurse("")) } Which version was easier to grok?
42. Before the second test we need some preparation //A class with some simple-to-understand attributes class Person(val name: String, val age: Int, val gender: String) //An appendable "array-like" class class ArrayBuffer ready?
43. So let's rock it! def version1(queued: Iterable[Person]): Iterable[Person] = { val (boyz, girlz) = queued.filter(_.age > 18) .partition(_.gender == "male") val boyzIn = boyz take (girlz.size / 2) val in = (boyzIn ++ girlz).to[Set] for (boy <- boyz if !in(boy)) println(s"Go home, ${boy.name}. Better luck tommorrow, kiddo!") in } def version2(queued: Iterable[Person]): Iterable[Person] = { val girlz = ArrayBuffer[Person]() val boyz = ArrayBuffer[Person]() for (person <- queued) { if (person.age > 18) { if (person.gender == "male") boyz.append(person) else girlz.append(person) } } val in = ArrayBuffer[Person]() in.appendAll(girlz) for (i <- 0 until boyz.size) { if (i < girlz.size / 2) in.append(boyz(i)) else println(s"Go home, ${boyz(i).name}. Better luck tommorrow, kiddo!") } return in }
44. SAME RESULTS?
45. MAYBE WE LEARNED SOMETHING “It is not only the violin that shapes the violinist, we are all shaped by the tools we train ourselves to use, and in this respect programming languages have a devious influence: they shape our thinking habits.” Edsger W. Dijkstra - Letter to the budget council of The University of Texas at Austin the whole letter is here www.cs.utexas.edu/users/EWD/OtherDocs/To%20the%20Budget%20Council%20concerning%20Haskell.pdf
46. WATCH OUT FOR THE "HAMMER SYNDROME" Try to get a deeper understanding of the tools at your disposal So you can take informed decisions about the best solution to the problem at hand "Conventional" solutions are stable but sometimes best tailored to yesterday's problems Look for opportunities to explore new ideas
47. A SHORT AND APPROXIMATE PARADE OF EXPLORATION OPPORTUNITIES FOR THE MODERN JAVA DEVELOPER
48. AT THE DESIGN LEVEL Conventional Unusual CRUD Domain Driven Design ORM Event Sourcing MVC CQRS
49. AT THE FRAMEWORK STACK LEVEL Conventional Unusual Servlet Play! JSP Vert.x JSF Typesafe Config Spring JOOQ Java-EE Gradle Maven sbt
50. AT THE LANGUAGE LEVEL Conventional Unusual java groovy javascript kotlin sql ceylon scala clojure haskell!
51. Have a look at 'S DEVOXX '13 PRESENTATION MATT RAIBLE to get some inspiration regarding modern web development technologies here is the video www.parleys.com/play/5298cbe3e4b039ad2298c9db/ and here the slides static.raibledesigns.com/repository/presentations/The_Modern_Java_Web_Developer_Bootcamp_Devoxx2013.pdf [beware! heavy pdf]
52. TIME TO TAKE OFF AND FLY A LITTLE HIGHER
53. THE OBJECT-ORIENTED VS. FUNCTIONAL DEBATE Even though it's hard to define both, we can try to identify some core features of each OOP FP Modularity/Scoping Composability Encapsulation (reduce dependencies) Abstraction Mathematical Reasoning (pureness & immutability) both approaches have reusability and simplicity as goals
54. SUGGESTED READINGS ON THE SUBJECT D.L. Parnas - On the Criteria To Be Used in Decomposing Systems into Modules www.cs.umd.edu/class/spring2003/cmsc838p/Design/criteria.pdf M.Odersky; M.Zenger - Scalable Component Abstractions lampwww.epfl.ch/~odersky/papers/ScalableComponent.pdf J.Hughes - Why Functional Programming Matters www.cse.chalmers.se/~rjmh/Papers/whyfp.html H.Abelson; G.J.Sussman - Structure and Interpretation of Computer Programs mitpress.mit.edu/sicp/
55. IMPEDANCE MISMATCH OOP attaches behaviour to data FP separates functions from data Interestingly, the FP approach to data is considered an in OOP anti-pattern
56. IMPEDANCE MISMATCH (DETOUR) Object Relational Mapping has been called “The Vietnam of Computer Science” Ted Neward cited in blog.codinghorror.com/object-relational-mapping-is-the-vietnam-of-computer-science/
57. IS RELATIONAL DATABASE ALWAYS THE BEST CHOICE? “Database Driven Development” anyone? Once again, keep watch for opportunities! NoSql NoDB!
58. STILL MORE HIGH LEVEL and a little out-of-the-box
59. WHERE'S INNOVATION IN THE PROGRAMMING WORLD? Internet of Things? Raspberry Pi? Arduino? Smart Glasses? ...?
60. WHO'S INNOVATING? Bill Gates? Steve Jobs? Mark Zuckerberg? ...?
61. What I'm looking after is tools that could change THE WAY WE THINK ABOUT PROGRAMMING in out daily work often with tech available even as we speak
62. TOOLS FROM THE NEAR FUTURE? REPL Scala Worksheet Chris Granger's Microsoft is also researching in the area of with along the same lines Light Table Elm debugger Swift Playground Live UI Programming TouchDevelop
63. As Light Table came out, Granger made some research to figure out “what's wrong in programming”, and what kind of solutions he could come up with His reasoning is better explained on his blog www.chris-granger.com/2014/03/27/toward-a-better-programming/ where he shows the progress of a new project called Aurora Similar ideas can be found on this blog entry about Legible Mathematics glench.com/LegibleMathematics/
64. WOLFRAM LANGUAGE knowledge based and cloud deployed math functions and algorithms data visualization nlp data and visualisation from many world-wide domains everything based on symbolic functions manipulation (includes symbols, images, docs, graphs...) Wolfram Data Framework ontology
65. THE PEOPLE WHO IMAGINED SUCH TOOLS stopped thinking about what we already know about software development and asked what we can actually do with the technology at our disposal can we stop taking for granted the way we develop and focus on how we would like to develop?
66. Most of the ideas we just saw were inspired by the creativity of this young talented guy BRET VICTOR His area of interest is the future of computing, education, data visualization and manipulation SUGGESTED MATERIAL INCLUDES The future of programming: Inventing on principle: Magic Ink: worrydream.com/#!/TheFutureOfProgramming worrydream.com/#!/InventingOnPrinciple worrydream.com/#!/MagicInk
67. INFLUENCES It strikes me how often Victor cites works and "explorers" from the historical or contemporary computer science research and other fields NAMES SUCH AS Alan Kay Douglas Engelbart Tony Hoare Edsger Dijkstra Alan Cooper Edward Tufte Don Norman Jeff Raskin David Hestenes
68. Many of these influencial people's stunning innovations, date back to the early days of the computer age THE POINT HERE IS HOW MUCH CAN WE LEARN FROM THE PAST?
69. “I have this strong feeling that the more I look into the latest approaches or hard problems in today's software, the more I find myself looking back” JUST ME
70. Whenever we discover new cool approaches and ideas about computer science, they're probably inspired by past research, tackling the same old fundamental issues DESIGN PATTERNS λ-CALCULUS TYPE SYSTEMS DATA REPRESENTATION BIG DATA DISTRIBUTED SYSTEMS ACTORS REACTIVE PROGRAMMING
71. QUOTING SOME HASKELL EVANGELIST? “One inconvenient thing about a purely imperative language is that you have to specify far too much sequencing. For example, if you wish to do a matrix multiplication, you have to do n³ multiplications. If you write an ordinary program to do this, you have to specify the exact sequence which they are all to be done. Actually, it doesn't matter in what order you do the multiplications so long as you add them together in the right groups. Thus the ordinary sort of imperative language imposes much too much sequencing, which makes it very difficult to rearrange if you want to make things more efficient.” P.J. Landin - The Next 700 Programming Languages, 1966 www.cs.cmu.edu/~crary/819-f09/Landin66.pdf
72. THOUGH THE INFORMATION AGE IS ALL AROUND US NOW, THE HISTORY OF SOFTWARE AND COMPUTERS IS STILL VERY YOUNG TO LOOK FORWARD WE ALSO NEED TO LOOK BACK
73. BACK FROM THE FUTURE
74. FUTURE OF: APPLICATIONS Sep 2013 the reactive manifesto - Feb 2009 (first public commit) support by the akka framework - 1990 (first presentation) inspired by erlang language - 1973 based on the actor model from Carl Hewitt - Hewitt; Bishop; Steiger; “A Universal Modular Actor Formalism for Artificial Intelligence. IJCAI” www.reactivemanifesto.org www.akka.io www.erlang.org
75. FUTURE OF: SOFTWARE DESIGN 2012 Uncle Bob Martin quotes an article about software design from Jack W. Reeves in his book on “Agile Software Development, principles, patterns and practices” 1985 the author published a reply to said article, after 13 years of reviews and comments - “What is software design: 13 years later” 1972 the original article - “What is software design?” 1962 the idea supported in the article, that “the code, as written by the developer, is the actual application design”, had been already clear to Reeves for 10 years www.developerdotstar.com/mag/articles/reeves_design_main.html
76. FUTURE OF: DATA MODELING THE LATE WILLIAM KENT'S BOOK “DATA & REALITY” 2012 (3rd ed.) updated and commented by Steve Hobermann 2000 (2nd ed.) reprinted practically unchanged from the original edition 1978 (1st ed.) 1967 - a sentence, quoted in the book preface “We do not, it seems, have a very clear and commonly agreed upon set of notions about data - either what they are, how they should be fed and cared for, or their relation to the design of programming languages and operating systems” [G.H.Mealy] Both Kent, in the first edition, and Hobermann, in the most recent, confirm the validity of this sentence from 1967 at the time of writing!
77. I think that innovation comes from the same open-minded approach of those past years, when the future of computing was still largely unwritten LEAVING BACK SOME UNNEEDED BAGGAGE COULD MAKE CREATIVITY SPROUT
78. POSSIBLE VISIONS OF SOFTWARE'S FUTURE Paul Chiusano - The future of software, the end of apps, and why UX designers should care about type theory pchiusano.github.io/2013-05-22/future-of-software.html Jamie Brandon - Imperative thinking and the making of sandwiches http://www.lighttable.com/2014/07/18/imperative-thinking/
79. CONCLUSIONS The interesting problems of computer science don't seem to have changed much over the last 50 years or so code reasoning/ease of use program correctness memory allocation/GC concurrency/parallelism distributed computing artificial intelligence/data mining ... We can get a lot of inspiration from field pioneers and research material NEVER STOP LEARNING
80. FREEDOM Being free is not about doing whatever we please, but about not being constrained by our limited knowledge
81. CONTACTS  plus.google.com/u/0/+IvanoPagano/  twitter.com/pagoda_5b  github.com/ivanopagano  stackoverflow.com/users/1237450/pagoda-5b  www.linkedin.com/in/ivanopagano
82. FURTHER DISCUSSION The problems of the past are not solved... Why? What can we do about it? WHAT IS YOUR POINT OF VIEW?
83. COPYRIGHTS NOTICE Lilo & Stitch copyrights belong to Walt Disney Pictures The Wolfram Language logo copyrights belong to Wolfram Research Inc. Back to the future copyrights belong to Universal Studios The Matrix copyrights belong to Warner Bros. Entertainment Inc. Questioning The Status Quo by Ivano Pagano is licensed under a . Based on a work at . Creative Commons Attribution- NonCommercial-ShareAlike 4.0 International License http://github.com/ivanopagano/questioning-status-quo