Drools：编译规则（或加载已编译规则）失败，并在 JamVM 中出现模糊异常
我正在开发一个框架，作为其功能之一，它使机器人能够使用基于规则的系统。我们开始使用 Jess 作为 RBS，现在想要实现 drools（使用 Drools 5.2.0 Final），它可以在运行 OpenJDK 6 的开发机器上运行。
我们的机器人控制器运行 ARM Linux 和 JamVM（之前为 1.4.3），但我最近编译了1.5.4，因为它缺少drools所需的类。失败后，我使用与为控制器编译 JamVM 时相同的配置在虚拟机中安装 JamVM，但它失败并出现相同的异常。
一些研究表明，Drools + JamVM 有错误报告，但这也意味着它通常可以工作。
当使用以下代码运行带有预编译规则的框架时......
kBase = KnowledgeBaseFactory.newKnowledgeBase();
ObjectInputStream in;
Collection<KnowledgePackage> kpkgs;
try {
in = new ObjectInputStream(Thread.currentThread().getContextClassLoader().getResourceAsStream(
packageFile));
kpkgs = (Collection<KnowledgePackage>) in.readObject();
in.close();
} catch(IOException e) {
throw new DisboticsException("Couldn't read drools knowledge package file!", e);
} catch(ClassNotFoundException e) {
throw new DisboticsException("Drools knowledge package file didn't contain expected instance.", e);
}
kBase.addKnowledgePackages(kpkgs);
kSession = kBase.newStatefulKnowledgeSession();
我得到了这个异常：
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:383)
at org.drools.rule.JavaDialectRuntimeData.merge(JavaDialectRuntimeData.java:266)
at org.drools.rule.JavaDialectRuntimeData.clone(JavaDialectRuntimeData.java:251)
at org.drools.rule.DialectRuntimeRegistry.merge(DialectRuntimeRegistry.java:110)
at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:496)
at org.drools.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:427)
at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:149)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:76)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Exception in thread "main" org.drools.RuntimeDroolsException: java.lang.UnsupportedOperationException
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:386)
at org.drools.rule.JavaDialectRuntimeData.merge(JavaDialectRuntimeData.java:266)
at org.drools.rule.JavaDialectRuntimeData.clone(JavaDialectRuntimeData.java:251)
at org.drools.rule.DialectRuntimeRegistry.merge(DialectRuntimeRegistry.java:110)
at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:496)
at org.drools.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:427)
at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:149)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:76)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Caused by: java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:383)
...9 more
......它在 OpenJDK 中工作。奇怪的是，事实证明 JavaDialectRuntimeData 中的相关列表是通过 Collections.emptyList() 获得的，并且再也不会改变（或者 eclipse 是这样建议的......）。
当使用以下代码运行裸 .drl 文件时：
Properties props = new Properties();
props.put("drools.dialect.java.compiler", "JANINO");
KnowledgeBuilderConfiguration kbConfig = KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(props,
(ClassLoader[]) null);
KnowledgeBuilder kBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(kbConfig);
kBuilder.add(ResourceFactory.newClassPathResource("disbotics/core/rules/drools/function.drl",
DroolsRulesPlugin.class), ResourceType.DRL);
kBuilder.add(ResourceFactory.newClassPathResource(rulesFile, DroolsRulesPlugin.class), ResourceType.DRL);
if(kBuilder.hasErrors()) {
String errorMessage = "";
for(KnowledgeBuilderError error:kBuilder.getErrors())
errorMessage = errorMessage + error.getMessage() + "\n";
throw new DisboticsException(errorMessage);
}
kBase = KnowledgeBaseFactory.newKnowledgeBase();
kBase.addKnowledgePackages(kBuilder.getKnowledgePackages());
kSession = kBase.newStatefulKnowledgeSession();
...我从规则编译器中得到这些（意外的）异常：
Exception in thread "main" disbotics.core.common.DisboticsException: Line 2:8 unexpected exception at input '"mvel"'. Exception: java.lang.UnsupportedOperationException. Stack trace:
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.lang.descr.PackageDescr.addAttribute(PackageDescr.java:138)
at org.drools.lang.api.impl.PackageDescrBuilderImpl.attribute(PackageDescrBuilderImpl.java:93)
at org.drools.lang.ParserHelper.start(ParserHelper.java:684)
at org.drools.lang.DRLParser.stringAttribute(DRLParser.java:1289)
at org.drools.lang.DRLParser.attribute(DRLParser.java:1062)
at org.drools.lang.DRLParser.statement(DRLParser.java:276)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:55)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
[ERR 107] Line 2:8 mismatched input '"mvel"' expecting one of the following tokens: '[package, import, global, declare, function, rule, query]'.
Line 4:0 unexpected exception at input 'global'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.globalStatement(DRLParser.java:401)
at org.drools.lang.DRLParser.statement(DRLParser.java:261)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:55)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Parser returned a null Package
Line 2:8 unexpected exception at input '"java"'. Exception: java.lang.UnsupportedOperationException. Stack trace:
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.lang.descr.PackageDescr.addAttribute(PackageDescr.java:138)
at org.drools.lang.api.impl.PackageDescrBuilderImpl.attribute(PackageDescrBuilderImpl.java:93)
at org.drools.lang.ParserHelper.start(ParserHelper.java:684)
at org.drools.lang.DRLParser.stringAttribute(DRLParser.java:1289)
at org.drools.lang.DRLParser.attribute(DRLParser.java:1062)
at org.drools.lang.DRLParser.statement(DRLParser.java:276)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
[ERR 107] Line 2:8 mismatched input '"java"' expecting one of the following tokens: '[package, import, global, declare, function, rule, query]'.
Line 4:0 unexpected exception at input 'import'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.importStatement(DRLParser.java:349)
at org.drools.lang.DRLParser.statement(DRLParser.java:258)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Line 6:0 unexpected exception at input 'rule'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.rule(DRLParser.java:886)
at org.drools.lang.DRLParser.statement(DRLParser.java:267)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Parser returned a null Package
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:63)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
再次，在 OpenJDK 中编译规则工作得很好。我们正在使用 Janino，并且它在类路径上被正确引用（运行时使用的类路径是由 Maven 构建创建的，因此包含 drools/janino/ 其他任何东西引用的所有 jar）
有谁知道这里发生了什么和/或如何让 Drools 与 JamVM 一起工作？
I'm developing a framework that, as one of its features, enables robots to use a rule based system. We began with Jess as the RBS, and now wanted to implement drools (using Drools 5.2.0 final), which works on our development machines running on OpenJDK 6.
Our robot controller runs ARM Linux and JamVM, previously 1.4.3, but I recently compiled 1.5.4 because it was missing classes needed by drools. After failures, I installed JamVM in a virtual machine using the same configurations as when I compiled it for the controller, and there it failed with the same exceptions.
A little research showed that there are bug reports for Drools + JamVM, but this also means that it generally does work.
When Running the framework with precompiled rules with the following code...
kBase = KnowledgeBaseFactory.newKnowledgeBase();
ObjectInputStream in;
Collection<KnowledgePackage> kpkgs;
try {
in = new ObjectInputStream(Thread.currentThread().getContextClassLoader().getResourceAsStream(
packageFile));
kpkgs = (Collection<KnowledgePackage>) in.readObject();
in.close();
} catch(IOException e) {
throw new DisboticsException("Couldn't read drools knowledge package file!", e);
} catch(ClassNotFoundException e) {
throw new DisboticsException("Drools knowledge package file didn't contain expected instance.", e);
}
kBase.addKnowledgePackages(kpkgs);
kSession = kBase.newStatefulKnowledgeSession();
...I got this exception:
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:383)
at org.drools.rule.JavaDialectRuntimeData.merge(JavaDialectRuntimeData.java:266)
at org.drools.rule.JavaDialectRuntimeData.clone(JavaDialectRuntimeData.java:251)
at org.drools.rule.DialectRuntimeRegistry.merge(DialectRuntimeRegistry.java:110)
at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:496)
at org.drools.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:427)
at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:149)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:76)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Exception in thread "main" org.drools.RuntimeDroolsException: java.lang.UnsupportedOperationException
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:386)
at org.drools.rule.JavaDialectRuntimeData.merge(JavaDialectRuntimeData.java:266)
at org.drools.rule.JavaDialectRuntimeData.clone(JavaDialectRuntimeData.java:251)
at org.drools.rule.DialectRuntimeRegistry.merge(DialectRuntimeRegistry.java:110)
at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:496)
at org.drools.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:427)
at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:149)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:76)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Caused by: java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.rule.JavaDialectRuntimeData.write(JavaDialectRuntimeData.java:383)
...9 more
...which works in OpenJDK. weirdly, it turns out that the list in question in JavaDialectRuntimeData is obtained via Collections.emptyList() and is never changed again (or so eclipse suggests...).
When running with bare .drl files using this code:
Properties props = new Properties();
props.put("drools.dialect.java.compiler", "JANINO");
KnowledgeBuilderConfiguration kbConfig = KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(props,
(ClassLoader[]) null);
KnowledgeBuilder kBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(kbConfig);
kBuilder.add(ResourceFactory.newClassPathResource("disbotics/core/rules/drools/function.drl",
DroolsRulesPlugin.class), ResourceType.DRL);
kBuilder.add(ResourceFactory.newClassPathResource(rulesFile, DroolsRulesPlugin.class), ResourceType.DRL);
if(kBuilder.hasErrors()) {
String errorMessage = "";
for(KnowledgeBuilderError error:kBuilder.getErrors())
errorMessage = errorMessage + error.getMessage() + "\n";
throw new DisboticsException(errorMessage);
}
kBase = KnowledgeBaseFactory.newKnowledgeBase();
kBase.addKnowledgePackages(kBuilder.getKnowledgePackages());
kSession = kBase.newStatefulKnowledgeSession();
... I get these (unexpected) exceptions from the rules compiler:
Exception in thread "main" disbotics.core.common.DisboticsException: Line 2:8 unexpected exception at input '"mvel"'. Exception: java.lang.UnsupportedOperationException. Stack trace:
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.lang.descr.PackageDescr.addAttribute(PackageDescr.java:138)
at org.drools.lang.api.impl.PackageDescrBuilderImpl.attribute(PackageDescrBuilderImpl.java:93)
at org.drools.lang.ParserHelper.start(ParserHelper.java:684)
at org.drools.lang.DRLParser.stringAttribute(DRLParser.java:1289)
at org.drools.lang.DRLParser.attribute(DRLParser.java:1062)
at org.drools.lang.DRLParser.statement(DRLParser.java:276)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:55)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
[ERR 107] Line 2:8 mismatched input '"mvel"' expecting one of the following tokens: '[package, import, global, declare, function, rule, query]'.
Line 4:0 unexpected exception at input 'global'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.globalStatement(DRLParser.java:401)
at org.drools.lang.DRLParser.statement(DRLParser.java:261)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:55)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Parser returned a null Package
Line 2:8 unexpected exception at input '"java"'. Exception: java.lang.UnsupportedOperationException. Stack trace:
java.lang.UnsupportedOperationException
at java.util.AbstractList.add(AbstractList.java:131)
at java.util.AbstractList.add(AbstractList.java:152)
at org.drools.lang.descr.PackageDescr.addAttribute(PackageDescr.java:138)
at org.drools.lang.api.impl.PackageDescrBuilderImpl.attribute(PackageDescrBuilderImpl.java:93)
at org.drools.lang.ParserHelper.start(ParserHelper.java:684)
at org.drools.lang.DRLParser.stringAttribute(DRLParser.java:1289)
at org.drools.lang.DRLParser.attribute(DRLParser.java:1062)
at org.drools.lang.DRLParser.statement(DRLParser.java:276)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
[ERR 107] Line 2:8 mismatched input '"java"' expecting one of the following tokens: '[package, import, global, declare, function, rule, query]'.
Line 4:0 unexpected exception at input 'import'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.importStatement(DRLParser.java:349)
at org.drools.lang.DRLParser.statement(DRLParser.java:258)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Line 6:0 unexpected exception at input 'rule'. Exception: java.util.EmptyStackException. Stack trace:
java.util.EmptyStackException
at java.util.Stack.pop(Stack.java:109)
at org.drools.lang.ParserHelper.popParaphrases(ParserHelper.java:421)
at org.drools.lang.ParserHelper.end(ParserHelper.java:732)
at org.drools.lang.DRLParser.rule(DRLParser.java:886)
at org.drools.lang.DRLParser.statement(DRLParser.java:267)
at org.drools.lang.DRLParser.compilationUnit(DRLParser.java:155)
at org.drools.compiler.DrlParser.compile(DrlParser.java:225)
at org.drools.compiler.DrlParser.parse(DrlParser.java:136)
at org.drools.compiler.DrlParser.parse(DrlParser.java:141)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:352)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28)
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:57)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
Parser returned a null Package
at disbotics.core.config.DroolsRulesPlugin.initialize(DroolsRulesPlugin.java:63)
at disbotics.core.common.DisboticsCore.startFramework(DisboticsCore.java:109)
at disbotics.core.common.DisboticsCore.main(DisboticsCore.java:56)
again, compiling the rules worked just fine in OpenJDK. We're using Janino, and it is properly referenced on the classpath (the classpath used at runtime is created by the Maven build, so contains all jars referenced by drools/janino/ anything else)
Does anyone know what's going on here and/or how to get Drools working with JamVM?
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您是否使用OpenJDK 1.6编译知识包？然后尝试用 1.5.4 加载它？您应该尝试使用 1.5.4 编译原始包，看看是否有相同的错误。
对于堆栈跟踪，看起来您正在尝试将某些内容添加到不可修改的列表中，对吗？
基本上你在这里得到异常： kBase.addKnowledgePackages(kpkgs);
正确的？
Are you compiling the knowledge packages using OpenJDK 1.6? and then trying to load it with 1.5.4? You should try compiling the original packages using 1.5.4 and see if you have the same errors.
For the stack trace, it looks like you are trying to add something to an unmodifiable list right?
Basically you are getting the exception here: kBase.addKnowledgePackages(kpkgs);
Right?