What JVM (2020)

• 🔗 Which Java SDK Should You Use?
  • 🔗 OpenJDK - java.net in sdkman.
  • 🔗 AdoptOpenJDK - binaries build from openjdk.
    • 🔗 Renamed in 2021 to Eclipse Adoptium Temurin
    • 🔗 OpenJDK Hotspot
    • 🔗 OpenJ9 VM - eclipse VM for low memory usage and fast start-up time.
  • 🔗 Amazon Corretto - only LTS versions. The versions that are used on AWS.
  • 🔗 Azul Zulu - versions from version 6 and forward. Used on MS Azure.
  • 🔗 BellSoft Liberica - versions with JavaFX, normal and embedded.

• JDKs in SDKMan

• Java editions:
  • 🔗 JavaFX - versions with client UI libraries (javafx.* packages). Not included in the standard JDK from version 11.
• Specialized virtual machines
  • 🔗 GraalVM
  • 🔗 TornadoVM

Java Performance Tools

• JMH - Java Microbenchmark Harness for microbenchmarking
• jHiccup for measuring JVM pauses due to GC

Versions

• LTS version every 3 years.
• non-LTS version every 6 months. In March and September.

Documentation

• 🔗 Java SE Documentation
• 🔗 Java Language and Virtual Machine Specifications
• 🔗 Secure Coding Guidelines for Java SE
• 🔗 mkyong -> What is new in Java 17
• 🔗 JVM Memory

Version 8 (LTS) - 2014-03

Java 8

• lambda expressions
• java.stream- stream API
• java.time- date & time API
• java.util.Base64 encoder and decoder
• nashorn javascript runtime

Version 9 - 2017-09

Java 9

• module system
• jlink for building custom runtime image
• jshell REPL

Version 10 - 2018-03

Java 10

• var - local-variable type inference
• graalvm
• run source code files without having to compile them
  • java Test.java

Version 11 (LTS) - 2018-09

Java 11

• HTTP client
• TLS 1.3
• jfr and jmc - for production profiling and monitoring
• new GC algorithms:
  • zgc
  • epsilon

Version 12 - 2019-03

Java 12

• new GC algorithms:
  • shenandoah

Version 13 - 2019-09

Java 13

Version 14 - 2020-03

Java 14