JDK 21: Unveiling the Exciting New Features in Java 21

Are you ready for the next big update in the world of Java? Get ready to explore the amazing features that JDK 21 has to offer! With a release date set for September 19, this long-term support (LTS) version of Oracle’s standard Java implementation is set to revolutionize the way developers work with Java. Let’s dive into the exciting features that will make Java 21 a game-changer.

1. Virtual Threads: Simplify and Scale Concurrency
   One of the most anticipated features in Java 21 is virtual threads. These lightweight threads bring simplicity and scalability to concurrent programming. By enabling server applications to scale with optimal hardware utilization, virtual threads make it easier to write and maintain high-throughput concurrent applications. With minimal changes required to existing code that uses the lang.Thread API, virtual threads open up a world of possibilities for developers.
2. Generational ZGC: Lower Overhead Garbage Collection
   Java 21 introduces generational ZGC, a garbage collector designed to reduce garbage collection overhead. By maintaining separate generations for young and old objects, ZGC can collect young objects more frequently, resulting in improved application performance. With lower risks of allocation stalls, reduced heap memory overhead, and decreased garbage collection CPU overhead, applications running with generational ZGC will experience significant benefits.
3. Key Encapsulation Mechanism (KEM) API: Enhanced Encryption
   Security is a top priority in Java 21, and the introduction of the KEM API reflects this. The KEM API enables applications to use key encapsulation mechanisms for securing symmetric keys through public cryptography. With support for algorithms like RSA-KEM and ECIES, developers can enhance encryption in their applications and integrate KEMs into higher-level protocols like TLS.
4. Structured Concurrency: Simplify Concurrent Programming
   Say goodbye to the complexities of concurrent programming with structured concurrency. This feature treats groups of related tasks running in different threads as a single unit of work, simplifying error handling, cancellation, and improving reliability. By streamlining concurrent code, structured concurrency enhances observability and makes concurrent programming more manageable.
5. Scoped Values: Share Immutable Data Safely
   Thread-local variables have limitations, especially when working with large numbers of virtual threads. Scoped values provide a safer alternative for sharing immutable data within and across threads. By allowing data to be shared without resorting to method arguments, scoped values improve performance and comprehensibility in large programs.
6. Deprecation of Windows 32-bit x86 Port: Moving Towards the Future
   In a forward-looking move, the Windows 32-bit x86 port is marked for removal in a future release of Java. This deprecation aligns with the end of life for Windows 10’s 32-bit support in October 2025. Developers are encouraged to update their build systems and consider alternative architectures to ensure compatibility with future Java releases.

These are just a few of the exciting features that JDK 21 brings to the table. From enhanced encryption to simplified concurrency and improved garbage collection, Java 21 is set to empower developers and revolutionize Java programming.

As a long-term support release, JDK 21 offers five years of premier support and extended support until September 2031. Stay tuned for the official release and get ready to unlock the full potential of Java with JDK 21.