Hutool 3.9 Jun 2026

is a lightweight, well-structured Java utility library that reduces boilerplate code. Version 3.9 represents a mature release in the 3.x series, focusing on:

: Wrapping complex native Java APIs into easy-to-use static methods. Hutool 3.9

// Watch multiple patterns with different handlers FileWatcherPro.of(Paths.get("/logs")) .onFiles("*.log", (path, event) -> // Auto-rotate logs on modification LogRotator.rotateIfNeeded(path); ) .onFiles("*.tmp", (path, event) -> // Auto-delete temp files after 1 hour FileUtil.del(path); ) .on(Paths.get("config.yml"), ENTRY_MODIFY, ENTRY_DELETE) .start(); // Runs on virtual thread is a lightweight, well-structured Java utility library that

(Note: Version 3.x used the com.xiaoleilu group ID; modern versions 4.x+ use cn.hutool .) , wrapping complex logic like Private/Public key generation

Version 3.9 introduced several critical optimizations and features that distinguished it from its predecessors.

, wrapping complex logic like Private/Public key generation and Hex/Base64 encoding into accessible tools. : Standard implementations for timed and size-limited caches