程式語言 - Drools - Hello, world!

參考資訊：
https://github.com/tkobayas/kiegroup-examples
https://www.cnblogs.com/lonecloud/p/12333309.html
https://blog.kie.org/2021/11/drools-basic-examples.html

資料結構


src/main/resources/com/sample/MyRule.drl

package com.sample

rule Hello
    when
        eval(true);
    then
        System.out.println("Hello, world!");
end

src/main/resources/META-INF/kmodule.xml

<?xml version="1.0" encoding="UTF-8"?>
<kmodule xmlns="http://jboss.org/kie/6.0.0/kmodule">
</kmodule>

src/test/java/com/sample/MyTest.java

package com.sample;

import org.junit.Test;
import org.kie.api.KieBase;
import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;

public class MyTest {
    @Test
    public void testRules() {
        KieServices ks = KieServices.Factory.get();
        KieContainer kcontainer = ks.getKieClasspathContainer();
        KieBase kbase = kcontainer.getKieBase();
        KieSession ksession = kbase.newKieSession();

        ksession.fireAllRules();
        ksession.dispose();
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sample</groupId>
    <artifactId>basic-example</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>kjar</packaging>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <drools.version>10.0.0</drools.version>
    </properties>

    <repositories>
        <repository>
            <id>jboss-public-repository-group</id>
            <name>JBoss Public Repository Group</name>
            <url>http://repository.jboss.org/nexus/content/groups/public/</url>
            <releases>
                <enabled>true</enabled>
                <updatePolicy>never</updatePolicy>
            </releases>
            <snapshots>
                <enabled>true</enabled>
                <updatePolicy>daily</updatePolicy>
            </snapshots>
        </repository>
    </repositories>

    <dependencies>

        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-engine-classic</artifactId>
            <version>${drools.version}</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.9</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
            </plugin>
            <plugin>
                <groupId>org.kie</groupId>
                <artifactId>kie-maven-plugin</artifactId>
                <version>${drools.version}</version>
                <extensions>true</extensions>
            </plugin>
        </plugins>
    </build>
</project>

測試

$ mvn clean test
    Hello, world!