【Drools】值得打工人学习的规则引擎Drools＜一＞

Fact：事实，是指在drools 规则应用当中，**将一个普通的JavaBean插入到Working Memory后的对象就是Fact对象**，Fact对象是我们的应用和规则引擎进行数据交互的桥梁或通道。

注意这里在properties标签中设置版本
 <properties>
        <java.version>1.8</java.version>
        <drools.version>7.28.0.Final</drools.version>
    </properties>

        <!-- start drools -->
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-core</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-compiler</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <dependency>
            <groupId>org.kie</groupId>
            <artifactId>kie-spring</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <dependency>
            <groupId>org.kie</groupId>
            <artifactId>kie-internal</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-templates</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-decisiontables</artifactId>
            <version>7.35.0.Final</version>
        </dependency>
        <!--  end drools   -->

<?xml version="1.0" encoding="UTF-8"?>
<kmodule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://www.drools.org/xsd/kmodule">
    <!--
       可以存在多个<kbase>标签；
       name属性值可以随意设置；
       packages：对应*.drl文件的resources路径

       ksession标签必须设置；一个或者多个标签，name属性值唯一

       -->
    <kbase name="test-rulesKB" packages="rules">
        <ksession name="test-rulesKS"/>
    </kbase>

</kmodule>

package rules
import com.qxy.drools.Customer

rule "customerAge"
no-loop true // 定义当前的规则是否 不允许多次循环执行,默认是 false,也就是当前的规则只要满足条件,可以无限次执行
lock-on-active true //将lock-on-active属性的值设置为true,可避免因某些Fact对象被修改而使已经执行过的规则再次被激活执行。
salience 1
when
$customer:Customer(age < 10)
then
$customer.setAge($customer.getAge() + 1);
update($customer)
System.out.println($customer.getName() + ",age:" + $customer.getAge());
end

import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;

/**
 * @author qxy
 * @date 2020/11/11 11:31 上午
 */
public class DroolTest {
    public static void main(String[] args) {
        KieServices ks = KieServices.Factory.get();
        KieContainer kc = ks.getKieClasspathContainer();
        KieSession ksession = kc.newKieSession("test-rulesKS");
        Customer customer1 = new Customer();
        customer1.setAge(1);
        customer1.setName("李三");
        Customer customer2 = new Customer();
        customer2.setAge(18);
        customer2.setName("李四");

        ksession.insert(customer1);
        ksession.insert(customer2);
        ksession.fireAllRules();
        ksession.dispose();
    }
 }