java 27

Java 27 is a runtime release whose most consequential changes arrive without any source-code migration, making it a topic for teams that benchmark before they upgrade. HotSpot enables compact object headers by default, selects the G1 garbage collector even on small machines, redacts sensitive values from Java Flight Recorder output, and prefers a post-quantum TLS 1.3 key-exchange option when the other endpoint supports it. Because JDK 27 changes behavior for applications that did not ask for it, the practical discussion around java 27 centers on memory, garbage collection, and TLS testing rather than routine compiler upgrades.