Uberconf 3

On Day 3 I went to Brian Sletten's Machine Learning sessions:

Machine Learning: Overview

"The term machine learning refers to the automated detection of
meaningful patterns in data."

Machine Learning: Natural Language Processing

Machine Learning: Deep Learning

Research into neural networks began in the 50s with the concept of emulating a neuron by summing a set of weighted inputs, with a response being triggered if the combined values exceeded a threshold.  This was known as a Perceptron.  A perceptron is a single-layer neural network.

Deep Learning refers to the use of neural networks that are more than one layer deep.

Machine Learning: TensorFlow

This brought things a bit more down to earth with the focus on a particular software implementation of machine learning algorithms.

This topic probably comes closest to something I'd be able to apply at work.  As I mentioned earlier, there was not a very strong lineup of Big Data topics.

TensorFlow uses GPGPU (General-purpose computing on graphics processing units) to accelerate processing.  I was aware that bitcoin mining software did this but this was the first time I saw this acronym or really became aware that GPGPU was being used for a lot of other things.  This is your excuse for getting a really expensive, top-of-the-line graphics card.  If we start applying machine learning algorithms at work, my guess is we will build on top of Spark MLib since we already have such a big investment in the Hadoop, Scala, Spark stack.  It's weird that Brian didn't mention this at all.

There's a JavaScript API called TensorFlowJS that allows you to run ML in your browser!  Your phone!  IOT devices!  And here's another thing you can debug in Chrome DevTools.

Links

• A visual introduction to machine learning
• Keras: The Python Deep Learning library
• Dl4j Deep Learning for Java
• TensorFlow.js
• scikit-learn: Machine Learning in Python
• Brian Sletten's Data Science and Machine Learning resources
• Vulkan
• Welcome to the Jungle Or, A Heterogeneous Supercomputer in Every Pocket

Books

• Doing Data Science
• The Master Algorithm: How the Quest for the Ultimate Learning Machine Will Remake Our World
• The Theory That Would Not Die: How Bayes' Rule Cracked the Enigma Code, Hunted Down Russian Submarines, and Emerged Triumphant from Two Centuries of Controversy
• Machine Learning with R ("Make sure you get the second edition")
• Deep learning with Python
• Perceptrons by Marvin Minsky (downloadable)

A few miscellaneous comments about the show in general...

Women are definitely better represented than in the bad old days.  I would say the percentage of women has increased from around 5% to 20 or 25%.

The Mac is still a popular choice and I didn't notice anyone else running Linux.

Ditch Gradle, maybe reconsider the whole corporate sponsorship thing.

Uberconf 2

Today I did 5 back-to-back sessions with Venkat Subramaniam.  If you've never had the pleasure, he is a high-energy and fun presenter who seems to have mastered quite a wide range of software development topics.

Exploring Modern Javascript

This was a fast and fun presentation.  I'm up to speed enough on JavaScript that I was able to keep up and complete the labs in time.  Modern JavaScript has map, reduce and filter, cool.  I got a little more practice with Visual Studio Code.  Venkat was going pretty fast and asked us to take a short break and even so, he just barely finished, so this might be a longer session that was trimmed to 3 hours.

Creating React Applications

I didn't fare quite so well on this one.  Why do they schedule presentations during nap time?  Also, I really could have benefited from spending a couple of hours doing the React 'hello world' exercises beforehand, the way I did with Vue.  Venkat was still zooming through the material like the Energizer Bunny.  When we got to the first exercise I found myself just staring at an empty JavaScript file without a clue.  I finished up the lab at dinner (with the benefit of having the solutions in front of me).  This wasn't a total loss but I definitely could have gotten more out of it.

Taking polyglot programming to the next level with GraalVM

This is a very cool and promising new technology.  I didn't have any trouble bringing up "hello world" using the GraalVM javac and java and building the insanely fast native image.  Being able to debug other languages in Chrome DevTools is another cool feature.

A fire alarm livened up one of the afternoon sessions.  Never a dull moment at Uberconf!

Panel discussion

One of the better questions was 'What strongly held opinion have you done a 180 on?'  Several speakers had responses along the lines of 'I used to think it was all about technical talent and skill, but now I realize relationships, collaboration and soft skills are more important.'  One panelist said he had pulled a 180 on Microsoft ('I used to be an irritatingly passionate Apple fanboy').

Here are some of the books mentioned by the panelists:

• Delta-V by Daniel Suarez
• You Are Not A Gadget by Jaron Lanier
• Heart of the Machine: Our Future in a World of Artificial Emotional Intelligence by Richard Yonck
• Thinking Machines: The Quest for Artificial Intelligence--And Where It's Taking Us Next by Luke Dormehl
• The Broken Earth Trilogy by N K Jemisin
• The Coddling of the American Mind: How Good Intentions and Bad Ideas Are Setting Up a Generation for Failure

There was an amusing moment where several of the panelists were describing their awkward manual systems (e.g. spreadsheets) for keeping track of books they want to read, books they have read, etc.  There was a barely audible comment from Brian Sletten 'goodreads.com'.  Goodreads is an awesome tool to manage your reading and share ratings and reviews with your friends about books you have read that I have been using since 2012 or so.  Be my goodreads friend.

Uberconf 1

This was the longest day, 7:30-20:00.

Highlights:

A Vue Perspective (3h) and Testing Vue with Raju Gandhi.
Based on my extremely limited exposure, Vue seems like the most elegant of the "big three" client side frameworks.  It's the framework that lacks a big corporate sponsor (Angular comes from Google and React comes from Facebook).

I used Visual Studio Code for the coding parts.  It feels like I am getting over the hump with this tool.  This free Microsoft IDE has really taken off in the last 2 years or so.  The thing about it that first caught my attention is its support for Spring Tool Suite 4.

Craig Walls' Securing Spring REST & OAuth was excellent.  I have used Spring Security at work a bit but was still feeling like it hadn't quite clicked for me, and this helped.  Oauth is a riddle wrapped in a mystery inside an enigma, but Craig makes it seem easy.

My final 'Uberconf after dark' presentation was Neal Ford 'Stories Every Developer Should Know'.  This was an entertaining collection of cautionary tales about projects that went disastrously wrong and lessons we can learn from them.  I never knew that Enterprise JavaBeans came out of something called the San Francisco Project at IBM.

Here's a couple of presentations from Spring One Platform 2017 about STS 4 and Visual Studio Code:
Spring Tools 4 - Eclipse and Beyond 
Erich Gamma at SpringOne Platform 2017 Visual Studio Code 

The "Keynote" with Hans Doktor of Gradle was just a naked infomercial.

Uberconf 0

Really impressive performance by the keynote speaker, Jessica Kerr.  All the audiovisual stuff died and she spoke from memory for 45 minutes or an hour.
The Origins of Opera and the Future of Programming Or: Collective problem solving in music, art, science, and software. appears to be identical or very close to the keynote speech.

Night before Uberconf 2019

Uberconf

It's been almost 5 years since my last NFJS event.

Back then I was complaining that there wasn't much new under the sun in the Java world.  The picture is a bit different today.  Java 8 and to some degree 9-12 have mostly addressed the concerns about the stagnation of the Java language itself.

The insane proliferation of JavaScript frameworks has shaken out somewhat with Angular, React and Vue emerging as the "big 3".  I work in AngularJS now and am feeling a bit less angstful about the whole client side than I did back in 2014.

One thing that is conspicuous to me in this year's lineup is quite a few more women presenters than in the past.  It will be interesting to see if there are more women attending this event which has traditionally been 95% male.

As always there are a bunch of agonizing choices to make.  Anybody got a Time-Turner?

A big focus at my employer right now is big data.  We are using Hadoop, Spark and Scala.  I think I first heard about Hadoop at NFJS 2010.  I see Scala on the schedule (cool language in its own right aside from big data) and a bunch of Machine Learning, but otherwise not that much.  I guess big data is ancient history these days and not that much of a focus in and of itself.

There's several talks about the recent Java releases and modular Java which kind of makes sense.  I gather a lot of users are used to sitting on the sidelines for the first year or so of a new Java release and aren't really up to speed on the new 6-month cadence.

Looks like Kotlin is a fairly hot topic.  I would kind of like to jump on this bandwagon but I'm still striving for Scala mastery... maybe next year.

There's a ton of Angular, React, Vue and JavaScript and I will probably be spending a bunch of time in these.  I'm doing better with client side than I have been for a long time but still see this as a weak area, especially with things moving so fast.

Craig Walls is going to be there with half a dozen or so Spring presentations.  Spring has been a special focus of mine for a long time.  In a way I'm working in Spring almost every day but all the new features like Reactive aren't that useful to my employer's business model, so I'm not really learning and getting hands on with something new every day.

I'm going to try to catch at least one of the GraalVM presentations, sounds cool and could be the wave of the future.  There's a lot of emphasis these days on performance and getting the fastest possible startup time for microservices.

Microservices, architecture, dev/ops, cloudy stuff, agile, security, soft skills...  It looks like NoSQL is pretty much played out as a topic.  There's still a couple of AMQP talks though Kafka is the new messaging hotness.

One last thing I'll mention, there's a talk called Web Components: The Future of Web Development is Here.  I went to a couple of talks about web components and polymer back in 2014, and, blown away by the clean, component-based model, wrote "The way most web development is done is going to completely change in the next year or so."  Well, that might be true, but not because of the widespread adoption of Web Components I envisioned.  But now, 5 years later, they really mean it!

Links

• React vs Angular vs Vue.js — What to choose in 2019?

Spring Boot, Spring Data JPA, jackson-dataformat-xml

At work, we had a RESTful web service application implemented in Groovy/Grails.  This probably started out as a SOAP web service and was then ported to Grails 1.1.1 (2009).  It worked, but had become almost unmaintainable due to the archaic tech stack.  Also, there was a desire to move away from Grails, which not many of the team knew, in favor of Java 8 and Spring.

This was about a one month project.  It built on the experience I got doing RESTful Web Service in Spring.

Since I was using Spring Boot, this web application could have run as a stand-alone Java app using the embedded servlet container support, and this is how I was debugging it at first, but the requirement was to have a drop-in replacement for the old Grails WAR file running in Wildfly, so that was an additional wrinkle.

The original service, which my program had to emulate closely, did not use HTTP methods in a RESTful manner, but instead mostly used GET and POST for everything.  This alone ruled out the use of Spring Data REST, so I needed to write controllers.

I started by creating a suite of integration tests which could be pointed at either the old or the new service.  This was invaluable for verifying that the new service performed identically to the old one.  Many problems in my implementation were exposed in time for me to correct them as a result of running these tests.

The application consists of a collection of endpoints, each providing read/write access to one table in the Oracle database.  Spring Data JPA really shone here.  I rarely needed to give much thought to the database access part and in the one case where I needed to do something outside of the method-name based query model (next value from an Oracle sequence), the native query escape hatch was there.  I think I like this better than GORM.  GORM tries to make everything easy for you but I always wound up spending a lot of time resolving issues with transactions, sessions and cascading... these issues just seem clearer and less hidden in Spring Data JPA.

For rendering the responses in XML, I used jackson-dataformat-xml.  See How to write an XML REST service.  At first I tried using the same classes for the database entities and the POJOs to be rendered into XML in the response, but the complexity of that soon got out of hand and I resorted to creating a separate set of DTO classes for the response POJOs.  This was the most unsatisfying part of the task for me, having this whole array of DTO classes with conversion methods ('from' and 'to')... it added a bunch of just infrastructure coding that had nothing to do with the business logic.

Going into Wildfly was mostly straightforward.  The one exception was authentication/authorization.  We had a custom Wildfly security domain which accessed LDAP for user data and Oracle for group and role data.  I was not able to find a generic way to support any Wildfly security domain with Spring Security.  I think the way to do this is with a custom authentication provider and user details service but the clock ran out on me and we went with something much simpler.

In the Wildfly environment I also needed to switch to using JNDI to resolve an Oracle data source configured in the container, but this is a breeze in Spring boot with

spring:
  datasource:
    jndi-name:    JNDI name of your data source here

in the application.yml file... this didn't take more than half an hour to figure out and make the change.

I had some difficulty at first getting the logging to work the way I wanted it to with the application deployed into a container.  I started out trying to keep the original Log4j 1.2.x configuration, but that doesn't seem to be very well supported in Spring Boot, and eventually I gave up and used Logback with a logback-spring.xml file.  This is one of those areas where there are a hundred different ways to do something and it's not always clear how to proceed.

Similarly, when it comes to configuring your Spring Boot application, there's such a wealth of features to support this, it's not always obvious what's the best way to meet a given requirement.  I wound up with two sets of application-(profile).yml files, one for running the application and one for running the integration tests

The service has been running in production for 3-4 weeks now.  This is the most ambitious Spring Boot and Spring Data project I have tackled and also marks an important milestone in our team's adoption of this technology.

Java 11

I worked through this example:

It’s time! Migrating to Java 11

It was mostly pretty straightforward.  One thing I couldn't figure out, while trying to run my modularized Spring Petclinic JAR, I was getting this error:

Two versions of module javafx.base found in target/modules (javafx.base-11.0.0-SNAPSHOT-win.jar and javafx.base-11.0.0-SNAPSHOT-linux.jar)

I looked in target/modules and discovered what looked like 3 platform-specific versions of the JavaFX JAR.  I removed them manually

rm target/modules/javafx.base-11.0.0-SNAPSHOT-win.jar
rm target/modules/javafx.base-11.0.0-SNAPSHOT-linux.jar
rm target/modules/javafx.base-11.0.0-SNAPSHOT-mac.jar 

and then I was able to run the JAR.

Googling the error yielded no matches.  Why does this non-graphical, server-side application even have any dependency on JavaFX?  What's up with 4 separate versions of this JAR?