What Is JDK (Java Development Kit) 17?

JDK (Java Development Kit) 17, also called Java Platform Standard Edition (Java SE) Development Kit 17, is a collection of tools for developing standard Java applications. JDK 17 is provided by Oracle.

JDK 17 was released on September 14, 2021. It is a Long-Term Support (LTS) version.

Some new features in JDK 17 are:

Sealed Classes - Sealed Classes have been added to the Java Language. Sealed classes and interfaces restrict which other classes or interfaces may extend or implement them.

Pattern Matching for switch - Enhance the Java programming language with pattern matching for switch expressions and statements, along with extensions to the language of patterns. Extending pattern matching to switch allows an expression to be tested against a number of patterns, each with a specific action, so that complex data-oriented queries can be expressed concisely and safely.

New macOS Rendering Pipeline - The Java 2D API used by the Swing APIs for rendering, can now use the new Apple Metal accelerated rendering API for macOS. This is currently disabled by default, so rendering still uses OpenGL APIs, which are deprecated by Apple but still available and supported. To enable Metal, an application should specify its use by setting the system property: "-Dsun.java2d.metal=true".

DatagramSocket Can Be Used Directly to Join Multicast Groups - java.net.DatagramSocket has been updated in this release to add support for joining multicast groups. It now defines joinGroup and leaveGroup methods to join and leave multicast groups. The class level API documentation of java.net.DatagramSocket has been updated to explain how a plain DatagramSocket can be configured and used to join and leave multicast groups.

Modernization of Ideal Graph Visualizer - Ideal Graph Visualizer (IGV), a tool to explore visually and interactively the intermediate representation used in the HotSpot VM C2 just-in-time (JIT) compiler, has been modernized. Enhancements include:

Experimental Compiler Blackholes Support - The experimental support for Compiler Blackholes is added. These are useful for low-level benchmarking, to avoid dead-code elimination on the critical paths, without affecting the benchmark performance. Current support is implemented as CompileCommand, accessible as -XX:CompileCommand=blackhole.

New Class Hierarchy Analysis Implementation in the HotSpot JVM - A new Class Hierarchy Analysis implementation is introduced in the HotSpot JVM. It features enhanced handling of abstract and default methods which improves inlining decisions made by the JIT-compilers. The new implementation supersedes the original one and is turned on by default.

⇒ Download and Install JDK 17 on Mac Computer

⇐ Using JDK 17 on Mac Computer

⇑ Using JDK 17 on Mac Computer

⇑⇑ FAQ for JDK (Java Development Kit) 17