I have the following code: (note String[] ruleFiles contains only one string)

public class Engine {

    private static RuleBase ruleBase;

    public void start(String[] ruleFiles) throws Exception {

        PackageBuilderConfiguration cfg = new PackageBuilderConfiguration();

        JavaDialectConfiguration javaConf = (JavaDialectConfiguration) cfg.getDialectConfiguration("java");

        javaConf.setCompiler(JavaDialectConfiguration.ECLIPSE);

        PackageBuilder builder = new PackageBuilder(cfg);

        for (String file : ruleFiles) {

            builder.addPackageFromDrl(new InputStreamReader(ClassLoader.getSystemResourceAsStream(file)));

        }

        Package pkg = builder.getPackage();

        PackageBuilderErrors errors = builder.getErrors();

        if (errors.getErrors().length != 0) {

            // do something

        }

        RuleBaseConfiguration conf = new RuleBaseConfiguration();

        conf.setAssertBehaviour(RuleBaseConfiguration.AssertBehaviour.EQUALITY);

        ruleBase = RuleBaseFactory.newRuleBase();

        ruleBase.addPackage(pkg);

        ruleBase.newStatefulSession(false);

    }

}

At the builder.addPackageFromDrl(new InputStreamReader(ClassLoader.getSystemResourceAsStream(file))); line I’m getting the following exception:

java.lang.NullPointerException

            at org.drools.rule.builder.dialect.java.JavaConsequenceBuilder.build(JavaConsequenceBuilder.java:54)

            at org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:67)

            at org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:446)

            at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:304)

            at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:167)

            at myPackage.rivoli.service.rules.Engine.start(Engine.java:33)

            at myPackage.rivoli.rules.LeaderKingAndHeirTest.setUp(LeaderKingAndHeirTest.java:26)

            at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:40)

            at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

            at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

            at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

            at com.intellij.rt.execution.application.AppMain.main(AppMain.java:90)

I am using Drools 4.0.3

I have the following jars in my class path:

antlr-runtime-3.0.jar

core-3.2.3.v_686_R32x.jar

drools-compiler-4.0.3.jar

drools-core-4.0.3.jar

mvel14-1.2.10.jar

Any ideas would be helpful. Thanks.

Michael Fuller

"In theory there is no difference between theory and practice. But, in practice, there is." - Jan L.A. van de Snepscheut