Jdk Version Guide

For over two decades, the Java Development Kit (JDK) has been the cornerstone of enterprise development, mobile applications (Android), and big data ecosystems. However, with the shift to a rapid six-month release cycle in 2017, keeping up with JDK versions has become a challenge for even seasoned developers.

| Step | Java 8 → 11 | Java 11 → 17 | Java 17 → 21 | | :--- | :--- | :--- | :--- | | | Remove JavaFX/Java EE; javax → jakarta | Update reflection code (encapsulation) | None (mostly additive) | | Tooling | Use jdeps to find internal APIs | Review --illegal-access warnings | Check for preview features | | Bytecode | Recompile or use --release 8 flag | Recompile recommended | Binary compatible | jdk version

| Provider | Best for | LTS Available | | :--- | :--- | :--- | | | General purpose, standard builds | 8, 11, 17, 21 | | Amazon Corretto | AWS environments, long-term free patches | 8, 11, 17, 21 | | Microsoft OpenJDK | Azure users, Windows integration | 11, 17, 21 | | Azul Zulu | Embedded systems, Apple Silicon optimization | All versions | | Oracle OpenJDK | Parity with Oracle (but free) | 8, 11, 17, 21 | Pro tip: Use SDKMAN! (Unix) or winget (Windows) to manage multiple JDK versions locally. 6. How to Check Your JDK Version # Command line basics java -version Example output (Java 21 LTS) openjdk version "21.0.2" 2024-01-16 LTS Runtime environment (Eclipse Temurin) build 21.0.2+13-LTS More detailed info java --version 7. Migration Strategy: Moving from Java 8 → 11 → 17 → 21 Migrating across LTS versions requires planning: For over two decades, the Java Development Kit