Ramen

Ramen is a simple, powerfull rule engine for Java and Scala. It is designed to be easy to use and to integrate into new or existing application.

Download

You can download the latest release from https://github.com/asgarth/ramen/releases.

Ramen rules use the MVEL (https://github.com/mvel/mvel) expression language to define both rule conditions and actions.

Getting started

The following snippet give a fast overview of the basic usage to define some rules in java code:

Person john = new Person("John", 15);
Person anna = new Person("Anna", 35);

Context context = new Context();
context.add("person", john);
context.add("person", anna);

Rule testStudent = new MVELRule("Test Student").on("person p").when("p.age < 18").then("p.student = true");

RuleEngine engine = new MVELRuleEngine();
engine.add(testStudent);

engine.eval(context);

System.out.println(john);
System.out.println(anna);

Define rule on multiple values

Context context = new Context();
context.add("person", new Person("John", 15));
context.add("person", new Person("Anna", 35));

Rule testStudent = new MVELRule("Always true")
    .on("person p1", "person p2")
    .when("true")
    .then("System.out.println('FIRED: ' + p1.name + ' - ' + p2.name)");

RuleEngine engine = new MVELRuleEngine();
engine.add(testStudent);

engine.eval(context);

Define some functions

Person john = new Person("John", 15);
Person anna = new Person("Anna", 35);

Context context = new Context();
context.add("person", john);
context.add("person", anna);

RuleEngine engine = new MVELRuleEngine();

engine.def(new MVELFunction("def setStudent(x) { x.student = true }"));
engine.add(new MVELRule("Test Student").on("person p").when("p.age < 18").then("setStudent(p)"));

engine.eval(context);

System.out.println(john);
System.out.println(anna);

Licence

Ramen is distributed under MIT License.