Drools学习三：新建项目

Step 1.

新建一个Drools项目

选择第一个，新建一个空项目，点击Next，输入项目名，点击Finish完成创建

此时会自动生成一些目录结构

        src.main.java.com.sample中存放java程序

        src.main.resources.com.sample中存放drools文件，分别为dtables决策表、process规则流、rules规则

Step 2.

添加JUnit单元测试框架，用来完成后面的项目运行工作

项目名称上单击鼠标右键，选择Build Path→Configure Build Path

 选择Java Build Path→Libraries→Add Library→JUnit→Next，选择JUnit版本点击Finish，应用并关闭设置窗口

 Step 3.

在com.sample目录下创建util文件夹，用来存放工具类

创建类KnowledgeSessionHelper用来生成drools服务

package com.sample.util;

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

public class KnowledgeSessionHelper {
	public static KieContainer createRuleBase() {
		KieServices ks = KieServices.Factory.get();
		KieContainer kieContainer = ks.getKieClasspathContainer();
		return kieContainer;
	}
	
	public static StatelessKieSession getStatelessKnowledgeSession(KieContainer kieContainer, String sessionName) {
		StatelessKieSession kSession = kieContainer.newStatelessKieSession(sessionName);
		return kSession;
	}
	
	public static KieSession getStatefulKnowledgeSession(KieContainer kieContainer, String SessionName) {
		KieSession kSession = kieContainer.newKieSession(SessionName);
		return kSession;
	}
}

 Step 4.

编写测试类并运行

package com.sample;

import org.junit.jupiter.api.Test;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;

import com.sample.util.KnowledgeSessionHelper;

class FirstTry {
	KieSession sessionStatefull = null;
	static KieContainer kieContainer;

	@Test
	void test() {
		kieContainer = KnowledgeSessionHelper.createRuleBase();
		sessionStatefull = KnowledgeSessionHelper.getStatefulKnowledgeSession(kieContainer, "ksession-rules");
		sessionStatefull.fireAllRules();
	}
}

 观察JUnit窗口是否运行成功，当然此时并没有规则被执行

Step 5.

 创建规则

在src/main/java/com/sample下创建新目录lesson1，用于存放规则

修改src/main/resources/META-INF目录下kmodule.xml文件，指向新的规则存放目录

<?xml version="1.0" encoding="UTF-8"?>
<kmodule xmlns="http://jboss.org/kie/6.0.0/kmodule">
    <kbase name="rules" packages="com.sample.rules">
        <ksession name="ksession-rules"/>
    </kbase>
    <kbase name="dtables" packages="com.sample.dtables">
        <ksession name="ksession-dtables"/>
    </kbase>
    <kbase name="process" packages="com.sample.process">
        <ksession name="ksession-process"/>
    </kbase>
    
    <kbase name="rules_lesson1" packages="com.sample.rules">
        <ksession name="ksession-rules-lesson1"/>
    </kbase>
</kmodule>

在新建的目录下新建规则文件lesson1.drl

修改lesson1.drl文件

//created on: 2020-2-14
package com.sample.lesson1

//list any import classes here.



//declare any global variables here




rule "Your First Rule"

    when
        //conditions
    then
        //actions
        System.out.println("Hello Drools");

end

rule "Your Second Rule"
    //include attributes such as "salience" here...
    when
        //conditions
    then
        //actions

end

再次执行FirstTry测试类，此时输出为

规则创建成功