Drools - Resource does not have neither a source nor a target path

问题

I'm very new to Drools and adapted the Spring Boot configuration i found here to enable me to read a bunch of rules from a Database as String's instead of reading them from DRL Files in an application folder.

When I startup my application using the code below i'm get the following exception using Spring Boot, Drools 6.5.Final, Java 1.8:

Caused by: java.lang.RuntimeException: Resource does not have neither a source nor a target path. Impossible to add it to the bundle. Please set either the source or target name of the resource before adding it.null at org.drools.compiler.kie.builder.impl.KieFileSystemImpl.write(KieFileSystemImpl.java:95) ~[drools-compiler-6.5.0.Final.jar:6.5.0.Final]

package com.example.demo;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

import org.kie.api.KieBase;
import org.kie.api.KieServices;
import org.kie.api.builder.KieBuilder;
import org.kie.api.builder.KieFileSystem;
import org.kie.api.builder.KieModule;
import org.kie.api.builder.KieRepository;
import org.kie.api.builder.ReleaseId;
import org.kie.api.io.Resource;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.kie.internal.io.ResourceFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class DroolsDatabaseConfig {

    @Autowired
    private DataService dataService;

    @Bean
    public KieFileSystem kieFileSystem() throws IOException {
        KieFileSystem kieFileSystem = getKieServices().newKieFileSystem();
        for (Resource resource : getRulesFromDB()) {
            kieFileSystem.write(resource);
        }        
        return kieFileSystem;
    }

    private List<Resource> getRulesFromDB() throws IOException {
        List<Resource> resources = new ArrayList<Resource>();

        List<String> rules = dataService.getRulesFromDB();
        for (String rule : rules){
            Resource r = ResourceFactory.newInputStreamResource(new ByteArrayInputStream(rule.getBytes(StandardCharsets.UTF_8)));
            resources.add(r);
        }
        return resources;
    }

    @Bean
    public KieContainer kieContainer() throws IOException {
        final KieRepository kieRepository = getKieServices().getRepository();

        kieRepository.addKieModule(new KieModule() {
            public ReleaseId getReleaseId() {
                return kieRepository.getDefaultReleaseId();
            }
        });

        KieBuilder kieBuilder = getKieServices().newKieBuilder(kieFileSystem()); 
        kieBuilder.buildAll();

        return getKieServices().newKieContainer(kieRepository.getDefaultReleaseId());
    }

    private KieServices getKieServices() {
        return KieServices.Factory.get();
    }

    @Bean
    public KieBase kieBase() throws IOException {
        return kieContainer().getKieBase();
    }

    @Bean
    public KieSession kieSession() throws IOException {
        return kieContainer().newKieSession();
    }
}

Any ideas on how i can resolve this to allow me load the Rules from a String?

Thanks in advance

来源：https://stackoverflow.com/questions/45265687/drools-resource-does-not-have-neither-a-source-nor-a-target-path