The phrase Denotational Semantics is an academic term for mapping programs to mathematical objects as a way to define their meanings. This phrase is not well-known in industry but we use it here to make it clear that this presentation is a shamelss rip off of a talk by Erik Meijer of a similar title. Erik Meijer, the founder of Applied Duality, is often cited as the inventor of 'reactive', a group of frameworks which have shown up in almost every programming language. The universal applicability of Meijer’s initial reactive framework is attributed by Meijer to long-established mathematical principles such as currying, duality, and coproducts. With these few simple constructions we can understand a wide variety of interfaces in a deeper way. As a practical example, we will cover Meijer’s derivation of Observable/Observer interfaces as duals of Iterable/Iterator interfaces. The takeaway is that every developer can apply denotational semantics to better design and implement common programs. Speaker Bio: Justin is an awesome, funny Math guy who’s became a Java prodigy in the last 5 years - switching from academia to the software industry. He holds a PhD in Mathematics from Northwestern University, and works at PCI as a Senior Principal Developer. He’s got a passion for system architecture and super-clean well-structured code. RSVP via Meetup: https://www.meetup.com/okcjug/events/260243783/ StarSpace46 / Techlahoma: 1141 W Sheridan Ave, Oklahoma City, OK 73106

Every developer creating real-world applications will have to eventually troubleshoot code performance issues - sometimes even in Production systems. In this session we will show a couple of essential tools that every Java developer should know about and can use to gather detail performance metrics (CPU, Memory, Threads, Hot Methods, etc.). With the help of these tools you can get to the bottom of tough issues such as bottlenecks caused by locking and memory leaks. We will specifically cover Java Mission Control (JMC), and Eclipse Memory Analyzer Tool (MAT). Speakers: Bill Spens is Director of Software Development at Power Costs, Inc. (PCI); He has 10 years of experience troubleshooting Java and Oracle performance and currently focuses on improving processes and efficiency across many agile teams. John Chesser has been writing Java on the front and back end for 18 years. John focuses on keeping it simple. He has experience writing full systems from scratch and maintaining older systems for companies like Creative Labs Inc. and Powercosts Inc. RSVP via Meetup: https://www.meetup.com/okcjug/events/258628656/ Clevyr: 912 N Classen Blvd, Oklahoma City, OK 73106 RSVP via Meetup: https://www.meetup.com/okcjug/events/258628656/ StarSpace46 / Techlahoma: 1141 W Sheridan Ave, Oklahoma City, OK 73106

In this session we will showcase the main features of Project Lombok (https://projectlombok.org) and demonstrate how you can make your Java code cleaner, more readable, and way less verbose. With the information shared in this talk you should be able to start using Lombok right away in your Java projects - even legacy projects. Speaker Bio Bryce Easly is a Senior Full Stack Developer who loves technology and has been developing web applications for almost a decade. He’s built complex systems using Java for Southwest Airlines, Power Costs Inc (PCI), and he’s currently at Tango Analytics.

We will start by introducing the concept of reactive programming and how it can benefit, simplify, and streamline software development and deployment. Then we will dig into the Reactor implementation of this idea, and finally we will run some code to show reactive at work. Speaker Bio Andres Barbaro is Vice President of Software Development at Power Costs, Inc. (PCI); Responsible for managing the software development and engineering practice across the entire organization and product portfolio. He has over ten years of experience in the energy industry, with an in-depth understanding of operations, trading, planning, and financial aspects of energy portfolios, specializing in business analytics and optimization. Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to StarSpace46 for providing the facility.

At the end of this month, Oracle is scheduled to release Java 11. In this session, we’ll see what’s new in the latest revision of the world’s most popular programming language. We’ll start with a rundown of features, including those added in Java 10 to get us to date, and end with examples of Java 11’s additions. IMPORTANT NOTE: Due to a scheduling conflict at StarSpace46, we will be meeting this month at Clevyr. Many thanks to Aaron Krauss for the hospitality! Speaker Bio Jason Lee is a Senior Member of the Technical Staff for Oracle working on the GlassFish Administration Console as well as the RESTful Administration interface. Jason has extensive experience working with web-based technologies such as JavaServer Faces and Ajax, as well as many other enterprise technologies based on the GlassFish platform. Jason has been writing software professionally since 1997 in a wide variety of languages and environments, including Java, PHP, C/C++, and Delphi on both Linux/Unix and Windows. You can read more about what Jason’s working on at his blog. Most importantly, Jason is married to a beautiful woman and has two sons who, thankfully, look like their mother. Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to Clevyr, Inc for providing the facility.

Rust is a systems language from Mozilla designed for speed, safety, and fearless concurrency. For the Java developer looking to expand horizons, it has features and ideas that you may not even realize that you were missing. Speaker Bio Mitch Blevins has been programming Java for 13 years and was an early Scala fanboi. He is currently fascinated by Rust. Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to StarSpace46 for providing the facility.

One of the biggest hypes about Java 9 is the Java Platform Modular System (JPMS) or Project Jigsaw. Modules give us 3 core principals: Strong Encapsulation Stable Abstraction Explicit Dependencies In this talk we will discuss the history of JPMS, look at some of its core features and do some demos. Speaker Bio Brent Wilkins is a Senior Java Developer at Hobby Lobby, where he works on the HobbyLobby.com ecommerce website as a full-stack developer. Before that he spent 25 years in IT at The Hertz Corporation developing and architecting the full-stack Java platform for their US Rent-A-Car locations. Slides for the presentation: Java 9 Modules Steps to recreate the Demo: Java 9 Modules - Notes Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to StarSpace46 for providing the facility.

One of the many strengths of Kotlin is the ease with it allows us to write Domain Specific Languages. Perhaps you’ve seen Anko for Android, or maybe TornadoFX for JavaFX and gotten the itch to write your own, or maybe just wondered how its done. Wonder know more! In this session, we’ll start from the beginning as we build Jerkey, Kotlin-based DSL for building Jersey applications (Jersey + Kotlin = Jerkey ;). We’ll start by covering the basics you need to understand in order write a DSL. Next, we’ll spec out how we want the DSL to look and work, and, finally, we’ll implement it and in doing so demonstrate not only the power of Kotlin, but how well the Kotlin/Java interop really is by showing code paths bouncing between Java and Kotlin code. fun willBeHadByAll() \{ } Speaker Bio Jason Lee is a Senior Principal Software Engineer with Oracle, where he functions as his team’s architect. Prior to Oracle, he worked for NetSuite and Sun Microsystems, both of which were acquired by Big Red (so if you’re hoping to be acquired by Oracle, give him a call). With over 21 years of experience, he has worked with a number of programming languages (Java, C/C++, Javascript, PHP, Python, Delphi and so on) in a variety of industries, with Java — and Java EE — being the primary focus for well over a decade now. He found Kotlin a few years ago, and has been trying to use it everywhere possible. Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to StarSpace46 for providing the facility.

How to use Gremlin, and how to write a Gremlin query within a Java program. Speaker Bio Brent Shambaugh Please go to Meetup and sign up so we will have a count for the food. We thank Techlahoma for generously providing the food and drink, and to StarSpace46 for providing the facility.