Java 21 is the latest long-term support (LTS) version of the Java SE platform, released on September 19, 2023. It includes a series of new features and improvements that allow developers to write more efficient, reliable, and secure Java applications.
New feature highlights
New features in Java 21 include:
Virtual Threads: Virtual threads are a new concurrency model that allows developers to write more efficient concurrent code without having to worry about the complexities of thread scheduling and synchronization.
Generational ZGC: ZGC is a new garbage collector designed to improve performance and scalability of large applications.
Key Encapsulation Mechanism API: The KEM API provides a way to securely generate and store encryption keys.
Supports the latest Unicode version: Java 21 supports the latest Unicode version, Unicode 15.
virtual thread
Virtual threads are a new concurrency model added in Java 21. A virtual thread is a lightweight thread that can be executed in parallel in multiple threads by the Java Virtual Machine (JVM). Virtual threads enable developers to write more efficient concurrent code without having to worry about the complexities of thread scheduling and synchronization.
Generational ZGC
The generational ZGC garbage collector is a new garbage collector added in Java 21. ZGC is a generation-based garbage collector designed to improve performance and scalability of large applications. ZGC can collect the entire heap in parallel, which can reduce application pause times during garbage collection.
Key encapsulation mechanism API
The Key Encapsulation Mechanism (KEM) API is a new encryption API added in Java 21. The KEM API provides a way to securely generate and store encryption keys. The KEM API uses elliptic curve cryptography (ECC) technology, a faster and more secure encryption method.
Supports the latest Unicode version
Java 21 supports the latest Unicode version, Unicode 15. Unicode 15 includes new characters and symbols from around the world. Java 21 support ensures that your Java applications handle Unicode characters correctly.
Upgrade suggestions
If you are developing Java applications, it is recommended that you upgrade to Java 21 as soon as possible. New features and improvements in Java 21 can make your applications faster, more reliable, and more secure.
How to upgrade
To upgrade to Java 21, you need to download the latest Java Development Kit (JDK). You can download the JDK from Oracle's website.
Conclusion
Java 21 is an important release of the Java platform, and it contains a series of features that will interest developers of all types. If you are developing Java applications, I encourage you to master Java 21 as soon as possible and try it out, and then upgrade when the time is right.