Java 25 — Skill

Java 25 (GA 2025-09-16) is the current LTS. This skill teaches the patterns that make Java 25 code shorter, safer, and more domain-oriented than Java 21, and embeds an opinionated DDD convention you can drop into any code review.

When to Use

Reach for this skill whenever you are:

• Writing new Java code targeting JDK 25 (LTS).
• Using any of the new language features: import module, compact source files + instance void main(), flexible constructor bodies, primitive patterns.
• Adopting finalized concurrency / API tools: Stream Gatherers, Scoped Values, Structured Concurrency, KDF API.
• Tuning runtime/GC with Compact Object Headers, Generational Shenandoah, or the simplified AOT cache.
• Modeling domain types — this skill enforces record first and forbids the Dto suffix.
• Migrating a service from Java 21 → Java 25 (delta table + checklist in references/migration-21-to-25.md).

Critical Patterns

Pattern 1 — Module Imports kill ceremony