ngadde / spring-boot-drools

Spring Boot sample application with Drools rules

Spring Boot Drools sample Application

Spring Boot sample application with Drools rules

Sample application that will load all drools rules on startup and will expose a webservice to pass the object and execute rules on the object.

TLDR; This is not tested for production quality in the scale of 100s and thousands of rules.

Singleton KieSession Bean

KieSession is wrapped in a Spring Singleton Bean.

/**
 * Singleton class that wraps
 * the Drools KieSession and is responsible
 * for loading rules and firing rules.
 */
@Component
public class RulesService {

    private KieServices ks;
    private KieContainer kContainer;
    private KieSession kieSession;

    @Bean("accountService")
    @Scope(value = ConfigurableBeanFactory.SCOPE_SINGLETON)
    public RulesService getRulesService() {
        return new RulesService();
    }

    /**
     * Function to initialize the kieSession.
     * This will be initialized on
     * application startup.
     */
    public void initializeRules() {

        this.ks = KieServices.Factory.get();
        this.kContainer = ks.getKieClasspathContainer();
        this.kieSession =  kContainer.newKieSession();
    }

    public int fireRules(Item item) {
        this.kieSession.insert(item);
        return this.kieSession.fireAllRules();

    }
}

Web Service to pass Object and execute rules.

@RestController
public class RulesController {

    @Autowired
    RulesService rulesService;

    @PostMapping("/rules")
    public String index(@RequestBody Item item) {
        int fired = this.rulesService.fireRules(item);

Sample JSON call to pass Object

HTTP POST
http://localhost:8080/rules
{
	"id": 2,
	"name": "Test",
	"cost": 100
}