当我尝试从SBT运行程序时，Drools无法编译规则

Question

我是Drools的新手；我试图通过示例来学习Drools，但似乎我的设置有问题，因为我无法成功运行我的应用程序。

我的规则是：

package com.example.rules

import newexample.Person;

rule "Is of valid age"

    when
        $p : Person( age < 18 )
    then
        $p.setValid( false );
end

和设置：

<?xml version="1.0" encoding="UTF-8"?>
<kmodule xmlns="http://jboss.org/kie/6.0.0/kmodule">
    <kbase name="rules" packages="rules">
        <ksession name="ksession-rule"/>
    </kbase>
</kmodule>

当我尝试运行我的应用程序时，我得到这个错误：

... - Adding Service org.drools.compiler.kie.builder.impl.KieServicesImpl

... - Adding Service org.drools.compiler.builder.impl.KnowledgeBuilderFactoryServiceImpl

...  - Found kmodule: file:/.../poc-drools/target/scala-2.12/test-classes/META-INF/kmodule.xml
... - KieModule URL type=file url=/.../poc-drools/target/scala-2.12/test-classes
... - Unable to find pom.properties in /.../poc-drools/target/scala-2.12/test-classes
... - As folder project tried to fall back to pom.xml, but could not find one
... - Unable to load pom.properties from/.../poc-drools/target/scala-2.12/test-classes
... - Cannot find maven pom properties for this project. Using the container's default ReleaseId
... - Discovered classpath module org.default:artifact:1.0.0
... - KieModule was added: FileKieModule[releaseId=org.default:artifact:1.0.0,file=/.../poc-drools/target/scala-2.12/test-classes]
... - File 'rules/1th.drl' is in folder 'rules' but declares package 'com.example.rules'. It is advised to have a correspondance between package and folder names.
... - Unable to build KieBaseModel:defaultKieBase
Rule Compilation error : [Rule name='Is of valid age']
    com/example/rules/Rule_Is_of_valid_age734850681.java (1:0) : The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
    com/example/rules/Rule_Is_of_valid_age734850681.java (1:0) : The type java.io.Serializable cannot be resolved. It is indirectly referenced from required .class files
    com/example/rules/Rule_Is_of_valid_age734850681.java (3:136) : Implicit super constructor Object() is undefined for default constructor. Must define an explicit constructor
    com/example/rules/Rule_Is_of_valid_age734850681.java (6:369) : java.lang.Exception cannot be resolved to a type

我使用的是Scala 2.13、SBT 1.2.6、jvm1.8和MacOS，我已经在sdkamn上安装了JVM。当我用Maven初始化项目时，一切都在找！但在使用sbt时，我会遇到错误。

Answer 1

似乎当我的包含Drools的应用程序在与SBT相同的JVM进程中运行时，它遇到了可用类和类路径的问题！我没有找出真正的原因，但当我配置我的项目在单独的JVM进程中运行应用程序时，它起作用了：

fork := true