Oracle has confirmed, within the framework of Oracle DevLive Level Up, the java 20 availability, the most recent version of the development platform. It offers numerous improvements in performance, stability and security. In addition, the platform has been perfected with a view to improving productivity. Java 20 incorporates several updates, mainly focused on tracking functions that improve functions already present in previous versions. It also responds to seven proposals for improvement.
Oracle Java Development Kit (JDK) 20 provides language enhancements from the Amber OpenJDK project on registration patterns and pattern matching for expressions and switch statements. It also has enhancements to the Panama OpenJDK project for the interfacing of the Java Virtual Machine (JVM) and native code. In this aspect, the improvements are focused on the memory and foreign function API, and on the vector API.
Finally, new features in Java 20 related to Project Loom include improvements to scope values, virtual threads, and structured concurrency. These will make it easier for you to write, maintain, and observe high-performance concurrent applications.
The most significant Java 20 updates and enhancements in this new release are the second preview of registration patterns (JEP 432) and the fourth preview of pattern matching to switch expressions (JEP 433). The first allows users to nest record and type patterns to generate a powerful, declarative, and compatible method for navigation and data processing. Thus, developers extend pattern matching to enable more complex, compound data queries.
As for the second of these mentioned enhancements, it allows an extension of pattern matching to switch expressions. This causes an expression to be tested against multiple patterns, each with a specific action. Thus, complex queries that are data-oriented can be expressed concisely and with confidence.
Java 20 has several enhancements from the Loom project in preview or incubation phase. They are scope values and structured concurrency, both incubating; and the virtual threads, in the second preview. The first enables immutable data sharing on individual threads and between different threads. These are preferred over thread-local variables, and increase usability, robustness, and performance.
On the other hand, virtual threads allow the optimization of the process of writing, maintenance and observation of concurrent high-performance applications. This is achieved through the introduction of lightweight virtual children in the Java platform.
As for structured concurrency, it gives the opportunity to simplify multithreaded programming by treating several tasks executed in different threads as a single unit of work. Thus, error management and cancellation can be optimized, as well as improving reliability and increasing observability.
The Panama project preview functions new in Java 20 are the Memory API and External Functions, in Second Preview (JEP 434). With it, Java programs can interoperate with code and data outside of the Java runtime.
In addition, by efficiently invoking external functions, that is, code foreign to the Java Virtual Machine, and through secure access to external memory, the API allows Java programs to call native libraries and process native data. This without having to use the native Java interface. The Vector API (JEP 438), now in its fifth incubation, expresses vector computations that compile vector instructions at runtime on supported CPU architectures.
To these new features of Java 20 are added its Java Management Service supporta native OCI (Oracle Cloud Infrastructure) service, offering a single pane of glass for managing Java runtimes and applications in on-premises or cloud environments.
