Before the widespread adoption of the Java 8 Time API, DateUtil was a critical component. Version 3.9 offered thread-safe date parsing and formatting, addressing concurrency issues found in SimpleDateFormat .
For those on , the latest 5.x series is the recommended choice. It offers the newest features, performance improvements, and security patches. However, if you are stuck on JDK 7 , the 4.x series is your best and only option, as Hutool 5.x and later are not compatible with it. The 3.x series is now considered legacy, but its structure and APIs are largely forward-compatible. Hutool 3.9
Lack of robust, chainable utility methods. 3. Hutool 3.9 Core Features Before the widespread adoption of the Java 8