28 Apr
3 min
Rules engines on the JVM in 2026
Drools is no longer the only game in town. A look at Easy Rules, RuleBook, and when you should reach for a rules engine at all.
5 posts about rules.
Drools is no longer the only game in town. A look at Easy Rules, RuleBook, and when you should reach for a rules engine at all.
The KIE Workbench REST API lets you automate project setup in a fresh container — useful when VirtualBox keeps changing your IP address.
Just the essentials: a Spring Boot application exposing a Drools rules engine as an HTTP API, nothing more.
A reference project wiring Spring and Drools without the heavyweight KIE integration — hand-cranked and straightforward.
Drools's built-in sum accumulator silently converts BigDecimals to doubles. A custom accumulator to fix that before it corrupts your financial calculations.