Kenneth Kousen

Latest Features in Java

9:00 AM MDT

This workshop discusses the features added to Java since Java 8. After a review of the functional additions (streams, lambda expressions, and method references), topics will include Local Variable Type Inference (LVTI), collection factory methods, the Java shell, the new HTTP client, the enhanced switch statement, text blocks, records, pattern matching, and sealed classes.

Features will be demonstrated for Java versions from 8 through 17, using preview versions where available.

• Java Licensing and Release Schedule
• Functional Programming in Java
  • Lambda expressions
  • Method references
  • Streams
  • Optional data type
  • Static and default methods in interfaces
• The java.time Package
• Collection Factory Methods
  • List.of
  • Set.of
  • Map.of
  • Map.ofEntries
• Local Variable Type Inference
• JShell
• HTTP Client
• Enhanced Switch Statement
• Text Blocks
• Records
• Pattern Matching
• Sealed Classes
• Miscellaneous Features
• A bit about JPMS

Property-Based Testing: Concepts and Examples

10:30 AM MDT

Property-based testing (PBT) validates the expected behavior of a system by checking it against a range of data points. A well-chosen set of properties will give the user a lot of confidence that the system is behaving as expected. The idea is that when the code is modified, failures in the tests reveal problems that would not have been found otherwise. This talk will cover the basic principles and several examples of PBT, using the jqwik library.

PBT allows you to define invariants (like reversing a list twice should result in the original list) and verify that they hold given generated changes that include a wide range of random inputs, including edge and corner cases. The jqwik library works well with JUnit to provide an important part of your testing strategy.

Effective JUnit Jupiter, with AssertJ

1:00 PM MDT

The fundamental testing libraries in Java have undergone complete redesigns in the past few years. JUnit 5, known as JUnit Jupiter, redesigns the most well-known tool in all of testing. This talk will demonstrate the new features, how they are intended to be used, and discuss experimental ideas in the pipeline.

JUnit has been remarkably stable over the years and is one of the most widely adopted frameworks in the Java world. The latest version, JUnit 5, takes JUnit to the next level. Full of new features like conditional test execution, parametric testing, labeling and filtering tests, and more, it brings all the modern thinking on testing into the JUnit world. It also takes advantage of the functional features added to Java since version 8 to create a powerful, new library for testing your code.

Effective Mockito: Mocks, Stubs, and Spies

3:00 PM MDT

The Mockito framework is the most popular library for creating mocks, stubs, and spies for your tests. This talk reviews why and how you might want to do that, including unit vs integration tests, creating your own mocks and stubs, setting expectations, and verifying the results.

The Mockito documentation is notoriously misleading if you don't already know the principles behind the library. This talk gives an example that hopefully clears up any confusion and makes the docs useful. Many examples will be provided covering a wide range of capabilities. In addition to the basics, issues like mocking static methods, mocking final methods and classes, using spies for existing classes, and more will be examined.

Key Gradle Concepts And Practices

5:00 PM MDT

Gradle has been described as the open source project with the most documentation that doesn't help. Key concepts, like the different steps Gradle takes at initialization time, configuration time, and execution time are not obvious, but must be understood to use Gradle effectively. This talk will cover those topics, as well as how to use source sets, IDE integration, testing in parallel, the build cache, and multi-project builds.

New topics to be included based include writing your own custom tasks, using version constraints, archiving and expanding files and folders, and incremental builds for efficiency.

Recently revised to include dependency conflict resolution, lazy task creation, the TOML file for versioning, and more.

Mental Bookmarks and the Fractal Nature of Success

7:30 PM MDT

Good discussions are supposed to diverge from their intended path. Free association is a feature, not a bug, and helps you see new connections between ideas. Without structure, however, it can be difficult to add context to new ideas and understand how they relate to more immediate problems. This talk discusses the technique of mental bookmarks – how to remember where you were when a discussion diverged. In addition to giving you a reputation for having an amazing memory, the skill also helps with personal awareness in general.

To give the technique context, we'll look at the fractal nature of success – the way we tend to see our current environment in relative terms, always comparing ourselves to those slightly more successful and slightly less successful.

Upgrade to Modern Java: 2025 Deep Dive

9:00 AM MDT

Over the past few years, the basic idioms and recommended programming styles for Java development have changed. Functional features are now favored, using streams, lambda expressions, and method references. The new sixmonth release schedule provides the language with new features, like modules and local variable type inference, much more frequently. Even the new license changes in the language seem to complicate installation, usage, and especially deployment.

The purpose of this training course is to help you adapt to the new ways of coding in Java. The latest functional approaches are included, including using parallel streams for concurrency, and when to expect them to be useful. All the new significant features added to the language will be reviewed and evaluated, with the goal understanding what problems they were designed to handle and when they can be used effectively in your code.

Upgrade to Modern Java: 2025 Deep Dive

11:00 AM MDT

Over the past few years, the basic idioms and recommended programming styles for Java development have changed. Functional features are now favored, using streams, lambda expressions, and method references. The new sixmonth release schedule provides the language with new features, like modules and local variable type inference, much more frequently. Even the new license changes in the language seem to complicate installation, usage, and especially deployment.

The purpose of this training course is to help you adapt to the new ways of coding in Java. The latest functional approaches are included, including using parallel streams for concurrency, and when to expect them to be useful. All the new significant features added to the language will be reviewed and evaluated, with the goal understanding what problems they were designed to handle and when they can be used effectively in your code.