封装基础的获取KieSession的代码Base.java:

import org.apache.commons.lang3.StringUtils;
import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;

public class Base {
    public KieSession getSession() {
        KieServices kieServices = KieServices.Factory.get();
        KieContainer kieContainer = kieServices.getKieClasspathContainer();
        //kmodule.xml 中定义的 ksession name
        KieSession kieSession = kieContainer.newKieSession("all-rules");
        return kieSession;
    }

    public KieSession getSession(String agendaGroupName) {
        KieSession session = this.getSession();
        if (StringUtils.isNoneBlank(agendaGroupName)) {
            session.getAgenda().getAgendaGroup(agendaGroupName).setFocus();
        }

        return session;
    }
}

对应的规则调用程序FaceHandleTest:

/**
 * 测试 Facehandler
 * @author xiaojf 2018/1/23 21:35
 */
public class FaceHandleTest extends Base {
    @Test
    public void test() {
        KieSession kieSession = super.getSession("faceHandleTest");

        Person p = new Person();
        p.setAge(30);

        FactHandle faceHandle = kieSession.insert(p);
        //触发rules
        int count = kieSession.fireAllRules();

        System.out.println(p.getName());

        //在 work memory 中的对象描述信息
        System.out.println(faceHandle.toExternalForm());
        p.setAge(10);

        //更新work memory 中的对象信息
        kieSession.getAgenda().getAgendaGroup("faceHandleTest").setFocus();
        kieSession.update(faceHandle,p);
        kieSession.fireAllRules();

        Person p2 = (Person) kieSession.getObject(faceHandle);
        System.out.println(p2.getName());
      //删除
      //kieSession.delete(faceHandle);
} }

对应的规则文件内容:

package cn.xiaojf.rules

import cn.xiaojf.drools7.model.Person
rule "faceHandleTest-less-20"
agenda-group "faceHandleTest"
when
    $p : Person(age < 20)
    then
      $p.setName("less 20");
    end

rule "faceHandleTest-more-20"
agenda-group "faceHandleTest"
when
    $p : Person(age > 20)
    then
      $p.setName("more 20");
end

执行程序对应的结果:

more 20
0:1:429058804:429058804:1:DEFAULT:NON_TRAIT:cn.xiaojf.drools7.model.Person
less 20

Process finished with exit code 0

facehandler 相当于是work memory 中对象的句柄,通过facehandler 可以直接定位、修改、删除操作。



drools中FactHandle简介&示例插图

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