DEVOPSdigest

Oracle announced the availability of Java 24, the latest version of the programming language and development platform.

Java 24 (Oracle JDK 24) delivers thousands of improvements to help developers maximize productivity and drive innovation. In addition, enhancements to the platform's performance, stability, and security help organizations accelerate their business growth.

Language Features

■ JEP 488: Primitive Types in Patterns, instanceof, and switch (Second Preview): Helps developers increase Java programming productivity by making the language more uniform and expressive. This feature helps developers enhance pattern matching by removing restrictions pertaining to primitive types that developers encounter when using pattern matching, instanceof, and switch. It also allows primitive type patterns in all pattern contexts and extends instanceof and switch to work with all primitive types. Developers of applications that integrate AI inferencing will especially benefit from support of primitive types.

■ JEP 492: Flexible Constructor Bodies (Third Preview): Helps developers improve the reliability of code via the introduction of two distinct prologue and epilogue phases in a constructor body. This enables developers to more naturally place logic that they currently must factor into auxiliary static methods, auxiliary intermediate constructors, or constructor arguments. In addition, it preserves the existing safeguard that code in a subclass constructor cannot interfere with superclass instantiation, resulting in making a class more reliable when methods are overridden.

■ JEP 494: Module Import Declarations (Second Preview): Helps developers improve productivity by enabling them to quickly and easily import all the packages exported by a module, without requiring the importing code to be in a module itself. This simplifies the reuse of modular libraries for all developers and helps beginners more easily use third-party libraries and fundamental Java classes without needing to learn where they are located in a package hierarchy. This feature also benefits developers aiming to integrate business logic quickly with native AI inference, library, or service calls.

■ JEP 495: Simple Source Files and Instance Main Methods (Fourth Preview): Helps students write their first programs without needing to understand language features designed for large programs by offering a smooth on-ramp to Java programming. As a result, educators and instructors can introduce concepts gradually, and students can write streamlined declarations for single-class programs and seamlessly expand their programs with more advanced features as their skills grow. In addition, experienced Java developers can write small programs succinctly and efficiently without needing to use tools designed for larger projects.

Libraries

■ JEP 485: Stream Gatherers: Helps developers become more efficient in reading, writing, and maintaining Java code by enhancing the Stream API to support custom intermediate operations, which allow stream pipelines to transform data in ways that are not easily achievable with existing built-in intermediate operations.

■ JEP 484: Class-File API: Helps developers improve productivity by providing a standard API for parsing, generating, and transforming Java class files and tracking the class file format defined by the Java Virtual Machine specification.

■ JEP 487: Scoped Values (Fourth Preview): Helps developers increase the ease-of-use, comprehensibility, performance, and robustness of their projects by enabling the sharing of immutable data within and across threads.

■ JEP 489: Vector API (Ninth Incubator): Helps developers improve productivity by introducing an API to express vector computations that reliably compile at runtime to vector instructions on supported CPU architectures. As a result, developers can achieve performance superior to equivalent scalar computations, which are often used in AI inference and compute scenarios.

■ JEP 499: Structured Concurrency (Fourth Preview): Helps developers improve the maintainability, reliability, and observability of multithreaded code by simplifying concurrent programming via a new API for structured concurrency. By treating groups of related tasks running in different threads as a single unit of work, structured concurrency can help reduce common risks arising from cancellation and shutdown, such as thread leaks and cancellation delays.

Security Libraries

■ JEP 478: Key Derivation Function API (Preview): Helps developers prepare for emerging quantum computing environments by offering cryptographic security for data in transit. This improves confidentiality and communication integrity.

■ JEP 496: Quantum-Resistant Module-Lattice-Based Key Encapsulation Mechanism: Helps increase the security of Java applications by providing an implementation of the quantum-resistant Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM). This feature is an important step towards post-quantum readiness and the eventual delivery of post-quantum crypto (PQC) support for the Java platform, as key encapsulation mechanisms are used to secure symmetric keys over insecure communication channels using public key cryptography.

■ JEP 497: Quantum-Resistant Module-Lattice-Based Digital Signature Algorithm: Helps increase the security of Java applications by providing an implementation of the quantum-resistant Module-Lattice-Based Digital Signature Algorithm (ML-DSA). As with JEP 496, this feature is an important step towards post-quantum readiness and the eventual delivery of PQC support for the Java platform, as digital signatures are used to detect unauthorized modifications to data and to authenticate the identity of signatories. ML-DSA is designed to secure against future quantum computing attacks, and it has been standardized by the United States National Institute of Standards and Technology (NIST) in FIPS 204.

Tools

■ JEP 493: Linking Run-Time Images without JMODs: Helps developers increase efficiency by enabling the jlink tool to create custom run-time images without using the JDK's JMOD files, which can reduce the size of the JDK by approximately 25 percent. As a result, developers can link a run-time image from modules regardless of whether those modules are standalone JMOD files, modular JAR files, or part of a run-time image previously linked. This feature must be enabled when the JDK is built; it will not be enabled by default and some JDK vendors may choose not to enable it.

Performance and Runtime Updates

■ JEP 450: Compact Object Headers (Experimental): Helps developers increase productivity by reducing the size of object headers in the HotSpot JVM between 96 and 128 bits down to 64 bits on 64-bit architectures. This helps reduce heap size, improve deployment density, and increase data locality.

■ JEP 475: Late Barrier Extension for G1: Helps developers increase efficiency by shifting the expansion of the G1 garbage collector's barriers from early in the C2 JIT's compilation pipeline to later, which can reduce overhead if it occurs after platform-independent optimizations and register allocation. By simplifying the implementation of the G1 garbage collector's barriers, this feature helps increase the efficiency, comprehensibility, resiliency, and quality of C2-generated code.

■ JEP 483: Ahead-of-Time Class Loading & Linking: Helps developers increase productivity and improve startup time by making classes of an application instantly available in a loaded and linked state when the HotSpot Java Virtual Machine starts. This feature does not require the use of the jlink or jpackage tools, and it does not require any change to how applications are started from the command line or any change to the code of applications, libraries, or frameworks. As a result, it helps lay a foundation for continued improvements in startup and warmup time.

■ JEP 490: ZGC: Remove the Non-Generational Mode: Helps developers reduce the maintenance cost of supporting two different modes by removing the non-generational mode of the Z Garbage Collector (ZGC).

■ JEP 491: Synchronize Virtual Threads without Pinning: Helps developers increase productivity by extending the scalability of Java code and libraries that use synchronized methods and statements. By enabling virtual threads to release their underlying platform threads, this feature gives developers access to more virtual threads to manage their applications' workloads.

Source Code

■ JEP 404: Generational Shenandoah (Experimental): Helps developers increase productivity by enhancing the Shenandoah garbage collector with experimental generational collection capabilities that improve sustainable throughput, load-spike resilience, and memory utilization.

■ JEP 479: Remove the Windows 32-bit x86 Port: Helps developers increase efficiency by removing the source code and build support for the Windows 32-bit x86 port, which simplifies the JDK's build and test infrastructure.

■ JEP 501: Deprecate the 32-bit x86 Port for Removal: Helps developers increase productivity by deprecating the 32-bit x86 port with the intent to remove it in a future release. This helps developers gain access to new features that require platform-specific support without having to implement 32-bit x86 fallbacks.

In addition, by introducing modern, safe features while gradually deprecating and removing unsafe features, Oracle underscores its commitment to maintaining the integrity of Java and aligning with software development best practices. Oracle has designated three features for removal in a future Java release: JEP 472: Prepare to Restrict the Use of JNI; JEP 486: Permanently Disable the Security Manager; and JEP 498: Warn upon Use of Memory-Access Methods in sun.misc.Unsafe.

The features in the Java 24 release are a result of continuous collaboration between Oracle and other members of the global Java developer community via OpenJDK and the Java Community Process (JCP).

Java delivers increased innovation, performance, efficiency, and cost savings when deployed on Oracle Cloud Infrastructure (OCI), which is one of the first hyperscale clouds to support Java 24. By delivering Oracle Java SE, Oracle GraalVM, and the Java SE Subscription Enterprise Performance Pack at no additional charge on OCI, Java 24 helps developers create and deploy applications that run faster, better, and with optimized cost-performance.

The Oracle Java Universal SE Subscription provides customers with best-in-class support. It includes the Java SE Subscription Enterprise Performance Pack, triage support for the entire Java portfolio, entitlement to Oracle GraalVM, access to the advanced features of the Java Management Service, and the flexibility to upgrade at the pace of customers' businesses. This helps IT organizations manage complexity, mitigate security risks, and contain costs.