我如何在Drools 7中实现Drools 5示例

Question

I am new to Drools and I came across some Drools 5 examples which I intend to implement in Drools 7. However some classes which existed in Drools 5 are no longer available in Drools 7 for example DroolsParserException, PackageBuilder etc. I was wondering what their replacements are in Drools 7. I assume there may be KIE methods that correspond to these. This is the piece of code I am working on

public void executeDrools() throws DroolsParserException, IOException 
{
   PackageBuilder packbuild = new PackageBuilder();

   String ruleFile = "/com/rules/manufacturerRules.drl";

   InputStream inStream = getClass().getResourceAsStream(ruleFile);

   Reader reader = new InputStreamReader(inStream);

   packageBuilder.addPackageFromDrl(reader);

   Package rulesPackage = packbuild.getPackage();

   RuleBase ruleBase = RuleBaseFactory.newRuleBase();

   ruleBase.addPackage(rulesPackage);

   WorkingMemory inmemory = ruleBase.newStatefulSession();

   Garment manufactuer = new Garment();

   manufactuer.setQuota(10000);

   manufactuer.setExpectation(45000);

   manufactuer.setTimeline(10);

   inmemory.insert(manufactuer);

   inmemory.fireAllRules();

}

Sincerely appreciate some guidance on how to implement this using Drools 7. Thank you.

Answer 1

I finally accomplished my goal and I was able to successfully write the above piece of code in Drools 7. So to make it easy for anyone who is learning Drools 7 I cooked up a different example using some Java classes(ie Person and Insurance) which I already had. So for anyone using Drools this is the code you need to implement, everything except the runTheRule() and the ruleencapsulate() methods are generic you will have to use them in your code.

import java.io.IOException;
import org.drools.compiler.kie.builder.impl.InternalKieModule;
import org.drools.compiler.kie.builder.impl.KieContainerImpl;
import org.drools.compiler.kie.builder.impl.KieModuleKieProject;
import org.drools.compiler.kie.builder.impl.KieProject;
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.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.kie.internal.io.ResourceFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;


public class ruleClass {

     private static final String RULES_PATH = "C:/MyDrools_files/";
     private static final String RULES_FILE="DroolsLogic.drl";
     public ruleClass()
     {

     }
     public void runTheRule()
        {
            Person p=new Person();
            p.setTime(15);
            p.setName("Ulugh Khan");
            Insurance i=new Insurance();
            ruleencapsulate(p, i);

            System.out.println("--The Following is the output---");
            System.out.println(p.getGreet()+" "+i.getMessage());
        }
        private void ruleencapsulate(Person p, Insurance i)
        {
            try {
                KieSession chamSession=chkieSession();
                chamSession.insert(p);
                chamSession.setGlobal("insure", i);
                chamSession.fireAllRules();
            }
            catch(Exception e)
            {
                e.printStackTrace();
            }

        }
        private KieFileSystem chkieFileSystem() throws IOException 
        {
            KieFileSystem kieFileSystem = getchKieServices().newKieFileSystem();            
           try {
                for (Resource file : getchRuleFiles()) 
                {
                    org.kie.api.io.Resource theResource=ResourceFactory.newFileResource(file.getFile());        
                    kieFileSystem.write(theResource);                 
                }
           }
           catch(Exception ex)
           {
               ex.printStackTrace();
           }
                return kieFileSystem;
        }

        private KieContainer chkieContainer() throws IOException  
        {
           final KieRepository kieRepository = getchKieServices().getRepository();

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

            KieBuilder kieBuilder = getchKieServices().newKieBuilder(chkieFileSystem());
            kieBuilder.buildAll();

            ReleaseId release=kieRepository.getDefaultReleaseId();
            KieProject kieProject = new KieModuleKieProject((InternalKieModule) kieBuilder.getKieModule());
            KieContainer contains=new KieContainerImpl(kieProject, KieServices.Factory.get().getRepository(), release);
           return contains;   
        } 

        private KieSession chkieSession() throws IOException 
        {
            return chkieContainer().newKieSession();
        }

          private KieServices getchKieServices() 
          {
                return KieServices.Factory.get();
          }
          private Resource[] getchRuleFiles() throws IOException 
          {
             ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
             Resource[] resc=resourcePatternResolver.getResources("file:"+RULES_PATH+RULES_FILE);

             return resc; 
          }
}