Key: JDK-X - https://bugs.openjdk.java.net/browse/JDK-X CVE-XXXX-YYYY: https://cve.mitre.org/cgi-bin/cvename.cgi?name=XXXX-YYYY New in release OpenJDK 22.0.0 (2024-03-19): =========================================== Major changes are listed below. Some changes may have been backported to earlier releases following their first appearance in OpenJDK 22 through to 25. NEW FEATURES ============ Language Features ================= Statements before super(...) ============================ https://openjdk.org/jeps/447 In constructors in the Java programming language, allow statements that do not reference the instance being created to appear before an explicit constructor invocation (i.e. super()). This is a preview language feature (http://openjdk.java.net/jeps/12) introduced in OpenJDK 22 (JEP 447). Unnamed Patterns and Variables ============================== https://openjdk.org/jeps/443 https://openjdk.org/jeps/456 Enhance the Java language with unnamed patterns, which match a record component without stating the component's name or type, and unnamed variables, which can be initialized but not used. Both are denoted by an underscore character, _. This feature is now final. It was a preview feature (http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 443). String Templates ================ https://openjdk.org/jeps/430 https://openjdk.org/jeps/459 Enhance the Java programming language with string templates. String templates complement Java's existing string literals and text blocks by coupling literal text with embedded expressions and template processors to produce specialized results. This is a preview feature (http://openjdk.java.net/jeps/12) introduced in OpenJDK 21 (JEP 430) and reaching its second preview in OpenJDK 22 (JEP 459). Library Features ================ Foreign Function & Memory API ============================= https://openjdk.org/jeps/412 https://openjdk.org/jeps/419 https://openjdk.org/jeps/424 https://openjdk.org/jeps/434 https://openjdk.org/jeps/442 https://openjdk.org/jeps/454 Introduce an API by which Java programs can interoperate with code and data outside of the Java runtime. By efficiently invoking foreign functions (i.e., code outside the JVM), and by safely accessing foreign memory (i.e., memory not managed by the JVM), the API enables Java programs to call native libraries and process native data without the brittleness and danger of JNI. This API is now finalised. It was first introduced in incubation (https://openjdk.java.net/jeps/11) in OpenJDK 17 (JEP 412), and is an evolution of the Foreign Memory Access API (OpenJDK 14 through 16) and Foreign Linker API (OpenJDK 16) (see release notes for java-17-openjdk). OpenJDK 18 saw a second round of incubation (JEP 419) before its inclusion as a preview feature (http://openjdk.java.net/jeps/12) in OpenJDK 19 (JEP 424). A second preview took place in OpenJDK 20 (JEP 434) and a third and final preview in OpenJDK 21 (JEP 442). Class-File API ============== https://openjdk.org/jeps/457 Provide a standard API for parsing, generating, and transforming Java class files. This is a preview library feature (http://openjdk.java.net/jeps/12) introduced in OpenJDK 22 (JEP 457). Vector API ========== https://openjdk.org/jeps/338 https://openjdk.org/jeps/414 https://openjdk.org/jeps/417 https://openjdk.org/jeps/426 https://openjdk.org/jeps/438 https://openjdk.org/jeps/448 https://openjdk.org/jeps/460 Introduce an API to express vector computations that reliably compile at runtime to optimal vector hardware instructions on supported CPU architectures and thus achieve superior performance to equivalent scalar computations. This is an incubation feature (https://openjdk.java.net/jeps/11) introduced in OpenJDK 16 (JEP 338). A second round of incubation took place in OpenJDK 17 (JEP 414), OpenJDK 18 (JEP 417) saw a third, OpenJDK 19 a fourth (JEP 426), OpenJDK 20 (JEP 438) a fifth, OpenJDK 21 a sixth (JEP 448) and it reaches its seventh in OpenJDK 22 (JEP 460). Stream Gatherers ================ https://openjdk.org/jeps/461 Enhance the Stream API to support custom intermediate operations. This will allow stream pipelines to transform data in ways that are not easily achievable with the existing built-in intermediate operations. This is a preview library feature (http://openjdk.java.net/jeps/12) introduced in OpenJDK 22 (JEP 461). Structured Concurrency ====================== https://openjdk.org/jeps/428 https://openjdk.org/jeps/437 https://openjdk.org/jeps/453 https://openjdk.org/jeps/462 Simplify multithreaded programming by introducing an API for structured concurrency. Structured concurrency treats multiple tasks running in different threads as a single unit of work, thereby streamlining error handling and cancellation, improving reliability, and enhancing observability. This API was first introduced in incubation (https://openjdk.java.net/jeps/11) in OpenJDK 19 (JEP 428) and had a second round of incubation in OpenJDK 20 (JEP 437). It became a preview feature (http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 453) and reaches its second preview in OpenJDK 22 (JEP 462). Implicitly Declared Classes and Instance Main Methods ===================================================== https://openjdk.org/jeps/445 https://openjdk.org/jeps/463 Evolve the Java language so that students can write their first programs without needing to understand language features designed for large programs. Far from using a separate dialect of Java, students can write streamlined declarations for single-class programs and then seamlessly expand their programs to use more advanced features as their skills grow. This library feature was introduced as a preview (http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 445) under the name "Unnamed Classes and Instance Main Methods". It reaches a second preview in OpenJDK 22 (JEP 463) under a new name, due to the move away from unnamed classes to an implicitly declared name chosen by the host system. Scoped Values ============= https://openjdk.org/jeps/429 https://openjdk.org/jeps/446 https://openjdk.org/jeps/464 Introduce scoped values, which enable the sharing of immutable data within and across threads. They are preferred to thread-local variables, especially when using large numbers of virtual threads. This API was first introduced in incubation (https://openjdk.java.net/jeps/11) in OpenJDK 20 (JEP 429). It became a preview feature (http://openjdk.java.net/jeps/12) in OpenJDK 21 (JEP 446) and reaches its second preview in OpenJDK 22 (JEP 464). Virtual Machine Enhancements ============================ Region Pinning for G1 ===================== https://openjdk.org/jeps/423 Reduce latency by implementing region pinning in G1, so that garbage collection need not be disabled during Java Native Interface (JNI) critical regions. Tools ===== Launch Multi-File Source-Code Programs ====================================== https://openjdk.org/jeps/458 Enhance the java application launcher to be able to run a program supplied as multiple files of Java source code. This will make the transition from small programs to larger ones more gradual, enabling developers to choose whether and when to go to the trouble of configuring a build tool.