Introduced in 2004 alongside Java 5, Enums are a distinct type identified by their own keyword. They encapsulate a predefined, fixed set of named constants. This simple characteristic already provides ample value in our day-to-day code. However, their application extends beyond merely consolidating constants within a single type.

Project Loom, with its aim to deliver “easy-to-use, high-throughput, lightweight concurrency”, will most likely change how we approach concurrency in the future. Today, we will look at the “glue” that can hold it all together: Structured Concurrency.

Besides the “big” features that often aggregate under well-known project names, like “Amber”, “Loom”, or “Panama”, there are many little things in every release that are easy to miss. These API and tool improvements might not be as visible as other features, as they’re not represented by a JEP. That doesn’t mean we don’t need to know about them.

One of the most significant features of Java 21 is Virtual Threads (JEP 444). These lightweight threads reduce the effort needed for writing, maintaining, and observing high-throughput concurrent applications.

Around 6 years ago, I wrote about using Java for shell scripts. It was a hacky and fragile way to convert some Java code into a shebanged file containing the content of a Jar file. However, Java evolved quite a bit since that article, so it’s time to look at it again.

A new garbage collector was introduced in Java 11, a low latency/high scalability GC called ZGC. And now, with Java 21, it has evolved into a generational GChugo .