Hutool 3.9 Upd

If you are still maintaining legacy projects using the 3.x branch, ensure your pom.xml reflects the update:

In addition to new features, Hutool 3.9 includes several enhancements and improvements: Hutool 3.9 UPD

The old version had been graceful. The new version was technically correct but practically disastrous for legacy code that relied on null-safety at the deepest level. If you are still maintaining legacy projects using the 3