drools - get content of the rule based on name?

Question

We've got a web app that takes in lots of request params then invoke drools rules. I've got an event listener to capture what rule name is fired. However, I'd like to have a link to each of the rule that gets fired to point to the actual implementation of the rule. Is this possible?

Do I have to parse the .drl files and build a map of rule name to rule content? or pre-processing each rule name in a separate file name etc..? is there anything Drools API that given the name of the rule, it gives the content of the rule?

Any input is appreciated.

Thanks & regards voki

There's no such thing as the "rule content" to which you might have a link. Perhaps you modify the Q to describe what you really want to do (and I don't think it's poring over some object code). — laune

Arun Gowda Arun Gowda · Accepted Answer · 2020-09-12T07:53:40

For people from future, The following piece of code will get the rule content. Working on drools 7. Not sure about previous versions.

public String getRuleContent(String ruleName, String packageName) {
    Rule rule = getRule(ruleName,packageName)
            .orElseThrow(() -> new RuntimeException("Rule with name: " + ruleName + " does not exist in package: " + packageName));

    return new String(((ByteArrayResource) ((RuleImpl) rule).getResource()).getBytes());
}

public Optional<Rule> getRule(String ruleName, String packageName) {
    log.info("Getting rule by name: {} from {} package.",ruleName, packageName);
    KieBase kieBase = kieContainer.getKieBase();
    Collection<KiePackage> kiePackages = kieBase.getKiePackages();
    return kiePackages.stream()
            .filter(kiePackage -> kiePackage.getName().equals(packageName))
            .flatMap(kiePackage -> kiePackage.getRules().stream())
            .filter(r -> r.getName().equals(ruleName))
            .findFirst();

}

drools - get content of the rule based on name?

2 Answers