[extra Quality] | Hutool 3.9

While itself is an archived legacy version (current stable versions are 5.x and 6.x), it represents a critical phase where Hutool transformed from a personal utility kit into a comprehensive "Java Standard Library Supplement."

Hutool 3.x (Legacy) Core Philosophy: "Reduce the cost of learning and using Java APIs." hutool 3.9

For Java developers, particularly those maintaining legacy systems or working within the constraints of JDK 8, Hutool has long been the "Swiss Army Knife" of utility libraries. , released between late 2019 and early 2020, stands as a landmark version known for its stability and comprehensive feature set. While itself is an archived legacy version (current