It's time for the November Payara Monthly Catch! Our monthly news roundup ensures you get the best news of Java, Jakarta EE, MicroProfile, and open source. 

Let's have a look at the most interesting and important news from last month.

Garbage collection is a cornerstone feature in the Java Language. It automates memory management by reclaiming memory occupied by objects that are no longer in use, freeing you the developer up from manual memory allocation and deallocation tasks. This feature is vital for preventing memory leaks and ensuring that applications run efficiently over time.

Java's journey towards fostering more expressive and efficient code has taken a remarkable leap with the advent of Record Patterns, encapsulated in JEP 440. This feature, previewed in both Java 19 and Java 20, is now a part of the language from Java 21, marking a significant stride towards reducing the verbosity traditionally associated with Java language. In this post, we will delve into the essence of Record Patterns, take a look at its benefits, and explore how it fits in with the existing pattern matching capabilities of Java.

In the world of programming, stepping stones are crucial for novices to transition into proficient developers. This journey often begins with understanding the syntax and semantics of a given programming language. Java, being one of the popular programming languages, has always aimed to be an effective medium for both novices and experienced developers. The recent release of Java 21 introduced a core feature, known as Unnamed Classes and Instance Main Methods through JEP 445, aimed at simplifying the learning curve for new programmers, making it easier for them to write their first program without much fanfare and verbosity.

Pattern Matching for switch, introduced in Java 21 via JEP 441, marks a significant enhancement to the Java programming language, offering a more expressive and compact way to handle complex decision blocks. This feature extends the existing switch construct by allowing patterns in case labels, thus facilitating more concise, readable, and safe code when dealing with multi-way comparisons​​.

Java 21 introduces the Foreign Function and Memory (FFM) API, which allows Java programs to interoperate with code and data outside the Java runtime. Java operates within a managed environment known as the Java Virtual Machine (JVM). The JVM serves as an abstraction layer between the executing Java code and the underlying hardware and OS. One of the core design principles behind the JVM is to provide a secure and isolated environment for Java applications to run. This isolation is beneficial for several reasons, including security and stability; it mitigates risks such as unauthorized access to system resources or memory corruption, which could lead to vulnerabilities like buffer overflows.

Upcoming Java 21 brings a bunch of new features, including very interesting progress in concurrency. There are two main improvements – virtual threads and structured concurrency.

In this article, we discuss incoming usage of these enhancements inJakarta EE (formerly Java EE, now an open source project maintained by the Eclipse Foundation), a set of specifications that enables the worldwide community of Java developers to work on cloud native Java enterprise applications. Jakarta Concurrency is the concrete specification describing the expected behaviour.

The support in Jakarta EE is currently under development, details may change in the final implementation.