While newer versions like 5.x and 6.x are now available, the 3.9 era established the foundational modules that remain the bedrock of the library:
As an early version, Hutool 3.9 preceded the major updates found in the current Hutool 3.9
One of the most interesting aspects of the 3.9 build was its strict adherence to a zero-dependency While newer versions like 5
Whether you are processing collections, scraping HTTP endpoints with HttpUtil , generating QR codes (yes, 3.9 supports basic QR via QrCodeUtil ), or just formatting dates – Hutool 3.9 makes Java feel like a modern, high-level language. Hutool 3
One of the most controversial yet productivity-enhancing features of Hutool is its handling of checked exceptions. Java mandates that methods like FileUtil.copy handle IOException . Hutool 3.9 wraps these checked exceptions into unchecked RuntimeException (specifically UtilException ) by default. This decision adheres to the philosophy that 90% of I/O errors are unrecoverable in the immediate scope, thus freeing the developer from mandatory try-catch blocks that clutter the codebase.