Java New Features

A project to explore more about the new features from Java 8 through Java 21.

JDK Release Notes

OpenJDK Projects

• Valhalla: enhance Java object model with value objects and primitive values.
• Loom: project to bring user-mode threads.

Resume by Version

• Java 23

  • Primitive Types in Patterns, instanceof and switch (preview)
  • Class-File API (preview 2)
  • Stream Gatherers (preview 2)
  • Marketdown documentation comments
  • Module import declarations (preview)

• Java 22 (Mar, 2024)

  • Statements before super (preview)
  • FFM API (standard)
  • Unnamed Variable & Patterns
  • Launch Multi-File Source-Code Programs
  • String Templates (preview 2)
  • Stream Gatherers (preview)
  • Structured Concurrency (preview 2)
  • Scoped Value (preview 2)
  • Class-File API (preview)

• Java 21 (LTS; Sep, 2023)

  • Virtual Threads (standard) 🚀
  • Record Pattern (standard) 🚀
  • Pattern Matching for switch (standard) 🚀
  • Sequenced Collections
  • String Templates (preview)
  • Foreign Function & memory API (preview 3)
  • Unnamed Patterns and Variables (preview)
  • Unnamed Classes and Instance Main Methods (preview)
  • Prepare to Disallow the Dynamic Loading of Agents
  • KEM API
  • Structured Concurrency (preview)
  • Scoped Value (preview)

• Java 20 (Mar, 2023)

  • Scoped values (incubator)
  • Record pattern (preview 2)
  • Pattern matching for switch (preview 4)
  • Foreign Function & memory API (preview 2)
  • Virtual Threads (preview 2)
  • Structured concurrency (second incubator)

• Java 19 (Sep, 2022)

  • Virtual Thread (preview) 🚀
  • Pattern matching for switch (preview 3)
  • Vector API (fourth incubator)
  • Record pattern (preview)
  • Structured concurrency (incubator)

• Java 18 (Mar, 2022)

  • UTF-8 by Default
  • Simple Web Server
  • Code Snippets in Java API Documentation
  • Pattern matching for switch (preview 2)
  • Deprecated method finalize

• Java 17 (LTS; Sep, 2021)

  • Sealed classes (standard)
  • Pattern matching for switch (preview)
  • Enhanced Pseudo-Random Number Generator
  • Deprecate the Applet API for Removal
  • New macOS rendering for Java 2D API
  • Remove the experimental AOT and JIT compiler

• Java 16 (Mar, 2021)

  • Records (standard)
  • Pattern matching for instanceof (standard)
  • Sealed classes (preview 2)
  • Unix-Domain Socket Channels
  • Warnings for Value-Based Classes
  • Foreign-Memory Access API (incubator)
  • Vector API (incubator)
  • Foreign Linker API (incubator)
  • Packaging Tool

• Java 15 (Sep, 2020)

  • Sealed classes (preview)
  • Hidden classes
  • DatagramSocket reimplementation
  • Pattern matching for instanceof (preview 2)
  • Records (preview 2)
  • Foreign-Memory Access API (incubator)
  • GCs ZGC and Shenandoah turned final

• Java 14 (Mar, 2020)

  • Switch expression (standard)
  • Pattern matching for instanceof (preview)
  • Text blocks improvements (preview 2)
  • Records (preview)
  • Helpful NullPointerExceptions
  • Packaging tool
  • JFR even streaming

• Java 13 (Sep, 2019)

  • Switch expression (preview 2)
  • Text blocks (preview)
  • String API updates
  • NIO updates
  • Socket and ServerSocket reimplementation (Project Loom)
  • Dynamic CDS Archives
  • ZGC: Uncommit Unused Memory

• Java 12 (Mar, 2019)

  • Switch expression (preview)
  • Compact Number Format
  • Collectors improvements
  • CompletableFuture improvements
  • CDS enable by default
  • New GC and improvements

• Java 11 (LTS; Sep, 2018)

  • Removal of Java EE Modules, JavaFX and deprecated API
  • Http Client (incubator)
  • var in lambda expressions
  • API improvements
  • Null I/O

• Java 10 (Mar, 2018)

  • Process API improvements
  • Collections improvements
  • Application Class-Data Sharing
  • var keyword to declare variables

• Java 9 (Sep, 2017)

  • Milling Project Coin
  • Process API
  • Platform Logging API and Service
  • Concurrency improvements
  • Collections improvements
  • Project Jigsaw
  • Segmented code cache
  • JShell
  • much more (see JEPs)

• Java 8 (Marc, 2014)

  • API
  • Stream API
  • Project Lambda
  • Repeating annotations

Running

Java and Javac

You will need to provide the flag to enable preview and the number of Java version:

java --enable-preview --source 21 SourceCode.java

javac --enable-preview --source 21 SourceCode.java

JShell

To use JShell you can use the following flag:

jshell --enable-preview

Maven

• Maven: 3.5.0

  • compiler plugin: 3.8.0
  • surefire and failsafe: 2.22.0
  • plugins using ASM (e.g. the shade plugin) will likely need to be updated as well

  To run the examples with Maven use:

<plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <release>${java.version}</release>
        <compilerArgs>--enable-preview</compilerArgs>
    </configuration>
</plugin>
<plugin>
    <artifactId>maven-surefire-plugin</artifactId>
    <configuration>
        <argLine>--enable-preview</argLine>
    </configuration>
</plugin>
<plugin>
    <artifactId>maven-failsafe-plugin</artifactId>
    <configuration>
        <argLine>--enable-preview</argLine>
    </configuration>
</plugin>

Helpful Links

• OpenJDK Projects
• JDK Update Releases
• The Java Version Almanac
• Dev.java - tutorials, news and more
  • Java Platform Evolution
  • Java Playground
• Inside.java - Sip of Java
• Download Java versions:
  • The Role of Preview Features in Java and Beyond
  • Place to get early releases from Oracle's JDK
  • Oracle - Java Binaries Archive
  • Archived OpenJDK General-Availability Releases
• Considerations Bumping Java EE
• Migration tools:
  • Migrating From JDK 8 to Later JDK Releases
  • Eclipse Migration Toolkit for Java (EMT4J) Simplifies Upgrading Java Applications
  • Rewrite - Migrate to Java 17
• Presentations:
  • The Amazing Features of Modern Java - Venkat Subramaniam
• Java Projects:
  • Project Leyden - Capturing Lightning in a Bottle
• Blogs:
  • JDK Security Enhancements - Sean Mullan