Kenneth Kousen

President, Kousen IT, Inc.

Ken Kousen is a Java Champion, several time JavaOne Rock Star, and a Grails Rock Star. He is the author of the Pragmatic Library books “Mockito Made Clear” and “Help Your Boss Help You,” the O'Reilly books “Kotlin Cookbook”, “Modern Java Recipes”, and “Gradle Recipes for Android”, and the Manning book “Making Java Groovy”. He also has recorded over a dozen video courses for the O'Reilly Learning Platform, covering topics related to Android, Spring, Java, Groovy, Grails, and Gradle.

His academic background include BS degrees in Mechanical Engineering and Mathematics from M.I.T., an MA and Ph.D. in Aerospace Engineering from Princeton, and an MS in Computer Science from R.P.I. He is currently President of Kousen IT, Inc., based in Connecticut.

Presentations

A Java Tier List: Ranking the Features from Java 1.8 to 24

5:00 PM MDT

In this session, we'll rank the features added to Java between versions 1.8 and 24 (or whatever version is current at the time). Those include the basic functional features, like streams, lambdas, and method references, through code improvements like switch expressions, records, and pattern matching. We'll include simple topics like LVTI and collection factory methods, as well more recent additions like sealed interfaces and virtual threads. Vote for your favorite (and/or least favorite) feature!

Examples will demonstrate dataoriented programming concepts, combining sealed interfaces, records, pattern matching for switch, and more. Other examples will access RESTful web services, integrate with AI tool, and refactor existing Java 8 code to take advantage of new features.

Whispers of the Lost Hartford: An AI Opera Experience

7:30 PM MDT

AI tools are used to create a short libretto for a classic opera given a frankly ridiculous situation. Two models generate the text in tandem. Another model acts as a reviewer to evaluate the result. Illustrations are generated using an image generator. Snippets of music are created from parts of the text using a music system. A podcast is then generated discussing the quality and historical ramifications of the opera, using yet another model. It's AI models all the way down, with appropriately tragic results.

The idea is to evaluate the limits of what multimodal AI tools can and can not do, both individually and together.

Upgrade To Modern Java

9:00 AM MDT

This comprehensive presentation explores the evolution of Java from version 8 through 25, demonstrating how the language has transformed from an object-oriented platform into a modern, multi-paradigm programming language. Starting with Java 8's functional programming revolution—including lambdas, streams, and Optional—the presentation traces Java's journey through significant milestones like records, pattern matching, virtual threads, and data-oriented programming. Through practical code examples from a real repository, attendees will see how these features work together to create more expressive, maintainable, and performant applications.

The presentation begins with Java 8's game-changing features, using the ProcessDictionaryV2 example to showcase functional programming patterns, higher-order functions, and advanced Stream API usage including collectors like groupingBy and teeing. It then progresses through Java 9-11's quality-of-life improvements (var, HTTP Client, String enhancements), Java 12-17's language evolution (text blocks, records, pattern matching, sealed classes), and Java 18-21's modern capabilities (virtual threads for massive scalability, sequenced collections). Special attention is given to Data-Oriented Programming, demonstrating how records, sealed classes, and pattern matching combine to create a new programming paradigm. The presentation also covers cutting-edge features like unnamed variables (_) and looks ahead to Java 25 LTS with scoped values and performance improvements. Throughout, best practices are emphasized, including embracing immutability, leveraging pattern matching for cleaner code, using virtual threads for I/O-bound operations, and adopting modern APIs over legacy alternatives. All examples are drawn from the accompanying repository, providing attendees with working code they can explore and adapt for their own projects.

Upgrade To Modern Java

11:00 AM MDT

Claude Code

Anthropic’s Agentic Coding Tool

1:30 PM MDT

Discover how Claude Code, Anthropic’s new agentic coding assistant, is redefining developer productivity directly from the terminal. In this session, we’ll explore how Claude Code leverages advanced natural language understanding to help you refactor, document, and debug code using conversational prompts. See live demonstrations of how Claude Code can streamline complex workflows—handling multi-step tasks, automating documentation, accelerating debugging, and even running tests or linting—all in a single pass.

We’ll dive into the tool’s unique capabilities, including its reasoning and language comprehension, multimodal integration, and built-in Git support for seamless version control. You’ll walk away with a clear understanding of how to incorporate Claude Code into your daily development process, improving code quality, maintainability, and collaboration, while saving valuable time. Whether you’re new to AI-assisted coding or looking to expand your toolkit, this session will equip you with practical techniques to harness Claude Code’s full potential and transform your coding workflow.

Books

Modern Java Recipes: Simple Solutions to Difficult Problems in Java 8 and 9

by Ken Kousen

The introduction of functional programming concepts in Java SE 8 was a drastic change for this venerable object-oriented language. Lambda expressions, method references, and streams fundamentally changed the idioms of the language, and many developers have been trying to catch up ever since. This cookbook will help. With more than 70 detailed recipes, author Ken Kousen shows you how to use the newest features of Java to solve a wide range of problems.

For developers comfortable with previous Java versions, this guide covers nearly all of Java SE 8, and includes a chapter focused on changes coming in Java 9. Need to understand how functional idioms will change the way you write code? This cookbook—chock full of use cases—is for you.

Recipes cover:

The basics of lambda expressions and method references
Interfaces in the java.util.function package
Stream operations for transforming and filtering data
Comparators and Collectors for sorting and converting streaming data
Combining lambdas, method references, and streams
Creating instances and extract values from Java’s Optional type
New I/O capabilities that support functional streams
The Date-Time API that replaces the legacy Date and Calendar classes
Mechanisms for experimenting with concurrency and parallelism

Gradle Recipes for Android

by Ken Kousen

Using the Android Studio IDE and the Gradle build tool will make Android app development much simpler—as long as you know your way around Gradle. This practical guide shows you how Gradle works with Android so that you can use it effectively on your projects. You’ll learn ways to customize project layouts, add dependencies, and even generate multiple different versions of your application.

Use Gradle independently and from with the new preferred IDE, Android Studio
Integrate tests into standard Android project builds
Easily customize builds to add popular third-party libraries as dependencies
Generate artifacts with various properties, like debug or release, and different flavors, like paid or free

Making Java Groovy

by Ken Kousen

Summary

Making Java Groovy is a practical handbook for developers who want to blend Groovy into their day-to-day work with Java. It starts by introducing the key differences between Java and Groovy—and how you can use them to your advantage. Then, it guides you step-by-step through realistic development challenges, from web applications to web services to desktop applications, and shows how Groovy makes them easier to put into production.

About this Book

You don't need the full force of Java when you're writing a build script, a simple system utility, or a lightweight web app—but that's where Groovy shines brightest. This elegant JVM-based dynamic language extends and simplifies Java so you can concentrate on the task at hand instead of managing minute details and unnecessary complexity.

Making Java Groov is a practical guide for developers who want to benefit from Groovy in their work with Java. It starts by introducing the key differences between Java and Groovy and how to use them to your advantage. Then, you'll focus on the situations you face every day, like consuming and creating RESTful web services, working with databases, and using the Spring framework. You'll also explore the great Groovy tools for build processes, testing, and deployment and learn how to write Groovy-based domain-specific languages that simplify Java development.

Written for developers familiar with Java. No Groovy experience required.

Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications.

What's Inside

Easier Java
Closures, builders, and metaprogramming
Gradle for builds, Spock for testing
Groovy frameworks like Grails and Griffon

About the Author

Ken Kousen is an independent consultant and trainer specializing in Spring, Hibernate, Groovy, and Grails.

Table of Contents

PART 1: UP TO SPEED WITH GROOVY

Why add Groovy to Java?
Groovy by example
Code-level integration
Using Groovy features in Java

PART 2: GROOVY TOOLS

Build processes
Testing Groovy and Java projects

PART 3: GROOVY IN THE REAL WORLD

The Spring framework
Database access
RESTful web services
Building and testing web applications

Groovy Fundamentals [Online Code]

by

Number of Videos: 4 hours - 23 lessons
Author: Ken Kousen
User Level: Beginner
Learn the advantages of using Groovy by itself and with existing Java projects. This video workshop takes you into the heart of this JVM language and shows you how Groovy can help increase your productivity through dynamic language features similar to those of Python, Ruby, and Smalltalk. Presenter and Java consultant Ken Kousen demonstrates how writing anything from a simple build script to a full scale application is much easier with Groovy than with Java. You’ll quickly learn how to add Groovy to your projects, and then explore the language through a host of examples and demonstrations. Once you complete this course, check out Ken’s other videos on the subject: Practical Groovy and Mastering Groovy. - Walk through Groovy’s basic data types. Use the “slashy” string syntax to define regular expressions. - Learn how operator overloading in the libraries simplifies your code - Control and customize all the natural defaults and autogenerated code in POGOs - Get demonstrations on using closures, and mixing Java and Groovy classes together - Know when and how to use Abstract Syntax Tree (AST) transformations - Parse and generate both XML and JSON - Access RESTful web services with ease Ken Kousen, President of Kousen IT, Inc., is a technical trainer, mentor, and consultant in all areas related to Java, specializing in Android, Spring, Hibernate/JPA, Groovy, and Grails. He is the author of Making Java Groovy (Manning) and the upcoming O’Reilly book, Gradle for Android.

System Requirements:

Supported OS: [Mac Mountain Lion 10.8, Mac Lion 10.7, Mac Snow Leopard 10.6, Mac Leopard 10.5, Mac OS X, Macintosh]
Processor: Any
RAM: Any
Hard Disk: 3GB
Video Card: Any