我有这个类，它读取规则文件，插入事实和运行规则。
public class RuleRunner {
private KieServices kieServices = KieServices.Factory.get();
public enum RuleType {
XLS,
DRL;
}
private void prepareSession(String ruleResource, RuleType type) {
KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
Resource resource = kieServices.getResources().newClassPathResource(ruleResource);
switch(type) {
case XLS: {
resource.setResourceType(ResourceType.DTABLE);
break;
}
case DRL: {
resource.setResourceType(ResourceType.DRL);
break;
}
}
kieFileSystem.write(resource);
KieBuilder kieBuilder = kieServices.newKieBuilder(kieFileSystem);
kieBuilder.buildAll();
if (hasErrors(kieBuilder)) {
System.out.println("Failed to build!");
return;
}
}
private boolean hasErrors(KieBuilder builder) {
if (builder.getResults().getMessages().size() > 0) {
return true;
}
return false;
}
public void runRules(Object[] facts, GlobalVariable[] variables, String ruleResource, RuleType type) {
prepareSession(ruleResource, type);
KieContainer kieContainer = kieServices.newKieContainer(kieServices.getRepository().getDefaultReleaseId());
KieSession kieSession = kieContainer.newKieSession();
for (GlobalVariable variable: variables) {
kieSession.setGlobal(variable.getVariableName(), variable);
}
for(Object fact: facts) {
kieSession.insert(fact);
}
kieSession.fireAllRules();
kieSession.dispose();
}
}
我有这条规则
package com.pack.drools.apps;
import com.pack.drools.apps.domain.Person;
import com.pack.drools.apps.domain.GlobalVariable;
global GlobalVariable result
rule "if person has less that 10 cash then hes poor"
when
$person:Person(cash < 10)
then
result.setResult(-1);
end
rule "if person has more than 90 cash then hes rich"
when
$person:Person(cash > 90)
then
result.setResult(-2);
end
rule "if person has more than 10 and less than 90 then hes average"
when
$person:Person(cash >= 10 && cash <= 90)
then
result.setResult(-3);
end
但是当我尝试运行我的应用程序时
package pack.rup.drools.apps;
import pack.rup.drools.apps.core.RuleRunner;
import pack.rup.drools.apps.core.RuleRunner.RuleType;
import pack.rup.drools.apps.domain.GlobalVariable;
import pack.rup.drools.apps.domain.Person;
public class Main {
private static final String DEFAULT_PACKAGE = "pack/rup/drools/apps/";
private static final String XLS_FILE = DEFAULT_PACKAGE + "rule.xls";
private static final String DRL_FILE = DEFAULT_PACKAGE + "rule.drl";
public static void main(String[] args) {
RuleRunner ruleRunner = new RuleRunner();
// build fact
Person person = new Person();
person.setName("John");
person.setCash(100);
GlobalVariable result = new GlobalVariable();
result.setVariableName("result");
// ruleRunner.runRules(new Object[] { person }, new GlobalVariable[] { result }, XLS_FILE, RuleType.XLS);
ruleRunner.runRules(new Object[] { person }, new GlobalVariable[] { result }, DRL_FILE, RuleType.DRL);
System.out.println("Rule result: " + result.getResult());
}
}
我的日志看起来像这样
10:13:00.974 [main] INFO o.d.c.k.b.impl.KieRepositoryImpl - KieModule was added: MemoryKieModule[releaseId=org.default:arti
fact:1.0.0-SNAPSHOT]
10:13:00.982 [main] INFO o.d.c.k.b.impl.ClasspathKieProject - Found kmodule: file:/D:/workTestProjects/simpleDroolsApps/sda
-core/build/resources/main/META-INF/kmodule.xml
10:13:00.982 [main] DEBUG o.d.c.k.b.impl.ClasspathKieProject - KieModule URL type=file url=/D:/workTestProjects/simpleDrools
Apps/sda-core/build/resources/main
10:13:01.026 [main] WARN o.d.c.k.b.impl.ClasspathKieProject - Unable to find pom.properties in /D:/workTestProjects/simpleD
roolsApps/sda-core/build/resources/main
10:13:01.027 [main] WARN o.d.c.k.b.impl.ClasspathKieProject - As folder project tried to fall back to pom.xml, but could no
t find one for null
10:13:01.027 [main] WARN o.d.c.k.b.impl.ClasspathKieProject - Unable to load pom.properties from/D:/workTestProjects/simple
DroolsApps/sda-core/build/resources/main
10:13:01.027 [main] WARN o.d.c.k.b.impl.ClasspathKieProject - Cannot find maven pom properties for this project. Using the
container's default ReleaseId
10:13:01.027 [main] DEBUG o.d.c.k.b.impl.ClasspathKieProject - Discovered classpath module org.default:artifact:1.0.0-SNAPSH
OT
10:13:01.028 [main] INFO o.d.c.k.b.impl.KieRepositoryImpl - KieModule was added: FileKieModule[releaseId=org.default:artifa
ct:1.0.0-SNAPSHOT,file=D:\workTestProjects\simpleDroolsApps\sda-core\build\resources\main]
10:13:01.035 [main] WARN o.d.c.k.b.impl.AbstractKieModule - No files found for KieBase defaultKieBase, searching folder D:\
workTestProjects\simpleDroolsApps\sda-core\build\resources\main
10:13:01.131 [main] DEBUG o.drools.core.impl.KnowledgeBaseImpl - Starting Engine in PHREAK mode
Exception in thread "main" java.lang.RuntimeException: Unexpected global [result]
at org.drools.core.impl.StatefulKnowledgeSessionImpl.setGlobal(StatefulKnowledgeSessionImpl.java:1163)
at pack.rup.drools.apps.core.RuleRunner.runRules(RuleRunner.java:57)
at pack.rup.drools.apps.Main.main(Main.java:27)
:sda-core:run FAILED
答案 0 :(得分：2)
在将DRL或XLS资源写入KieFileSystem时，似乎必须使用特定目录。尝试
import com.pack.drools.apps.domain....
另外，你的DRL还有
import pack.rup.drools.apps.domain....
而在Main.java中有
Globals globals = kieSession.getGlobals();
System.out.println( globals.getGlobalKeys() );
这些导入应来自同一个包。
编辑要测试会话中的全局变量：
shareIntent.putExtra(Intent.EXTRA_STREAM, <instead pass imageuri>);
答案 1 :(得分：0)
我们与同事一起花费了2天的时间，最后发现当由于编译错误而导致您的DRL为空时，会发生“意外的全局”错误，这就是为什么addGlobal（）无法找到任何全局声明的原因。
一旦DRL编译器不会对错误抛出任何异常，您可以使用以下方法自己检查：
if (kieBuilder.hasErrors()) {
System.out.print( kieBuilder.getErrors() );
}
答案 2 :(得分：0)
如果插入一个全局变量，则必须使用它。例如，如果您有：
ArrayList<Thing> myThings = new ArrayList<Thing>();
kSession.setGlobal("myThings", myThings);
在DRL文件中，您必须至少具有一个匹配项：
global ArrayList<Thing> myThings;
否则，您将得到：
java.lang.RuntimeException: Unexpected global [myThings]
at org.drools.core.impl.StatefulKnowledgeSessionImpl.setGlobal(StatefulKnowledgeSessionImpl.java:1200)
at com.sample.ThingTest.test(ThingTest.java:37)