Don Raab

Java Champion. Creator of the Eclipse Collections OSS Java library. Inspired by Smalltalk. Opinions are my own.

Promoted Content

Step up your coding with the Continuous Feedback Udemy Course: Additional coupons are available

What do you know about the code changes that were just introduced into the codebase? When will you notice if something goes wrong?

Stable, Secure, and Affordable Java

Azul Platform Core is the #1 Oracle Java alternative, offering OpenJDK support for more versions (including Java 6 & 7) and more configurations for the greatest business value and lowest TCO.

Jakarta EE 11: Beyond the Era of Java EE

This user guide provides a brief history of Java EE/Jakarta EE and a detailed overview of some of the specifications that will be updated in Jakarta EE 11.

Likes 0

Comments 0

Shares 0

Articles 1

Views 6,4K

Immutable Collections in Java with Sealed Types

JDK 15 was released on September 15, 2020. JEP 360 Sealed Types was included as a preview feature in this release, with its second preview in JDK 16. Sealed Types is part of Project Amber. Sealed classes or interfaces can be used to restrict the interfaces or classes that are allowed to extend them. Also learn about the source code for an experimental implementation of a collections framework can be found in the Deck of Cards Kata repo.

Dec 10 6,4K

Don Raab

Sealed Classes

Tutorials

Retweet on Twitter Foojay.io Retweeted

Interesting read on @foojayio about the current state of the @grailsframework, at @TheASF
Written by @spoole167 interviewing @JamesFredley
https://foojay.io/today/grails-isnt-done-yet-part-1-inside-the-asf-reboot/

11:31 AM · March 25, 2026

Retweet on Twitter Foojay.io Retweeted

#Java 26 is here, and its main purpose is to provide a solid foundation for future things to come. It comes with new features, performance improvements and multiple enhancements–my blog post has all the info! 🚀

07:15 AM · March 17, 2026