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.
Tagged java
12 posts about java.
Using the KIE Workbench API to create a project
The KIE Workbench REST API lets you automate project setup in a fresh container — useful when VirtualBox keeps changing your IP address.
Multiple databases with Spring Boot and Spring Data JPA
Connecting a Spring Boot application to two separate databases with Spring Data JPA, working around Boot's default autowiring behaviour.
A minimal Spring Boot Drools web service
Just the essentials: a Spring Boot application exposing a Drools rules engine as an HTTP API, nothing more.
Bundling project dependencies with the Shade plugin
The Maven Shade plugin bundles all dependencies into a single fat jar — handy for deploying libraries into Drools Guvnor or running self-contained FitNesse fixtures.
A web service powered by Spring and Drools
A reference project wiring Spring and Drools without the heavyweight KIE integration — hand-cranked and straightforward.
A BigDecimal accumulator for Drools
Drools's built-in sum accumulator silently converts BigDecimals to doubles. A custom accumulator to fix that before it corrupts your financial calculations.
Getting the latest snapshot from Sonatype Nexus
A Ruby script to parse the Nexus REST API and reliably fetch the latest snapshot artifact, sidestepping the timestamped filename problem.
Multiple databases with Spring Data repositories
Configuring a Spring application with two separate data sources using Spring Data JPA — separate @Configuration classes and EntityManagerFactory beans for each schema.
Playing around with Apache Camel
First impressions of Apache Camel for implementing Enterprise Integration Patterns — a content-based router and a CSV-to-XML transform with almost no code.
WebLogic Scripting Tool scripts
Useful WLST resources and Gist examples for scripting WebLogic domain creation and server administration.
WebLogic Scripting Tool
BEA's Jython-based scripting tool for automating WebLogic server administration — create domains, manage deployments, and handle disaster recovery without restarting.