drools规则引擎——helloworld

drools规则引擎是基于rete算法的实现。

 

drools 按照我的想法是根据配置文件来写复杂逻辑的判断条件，方便改

应用场景：

　　应用于问题确定的场合；

　　适用于非流程性规则匹配；

 

规则引擎简易语法参考：http://blog.csdn.net/quzishen/article/details/6163012

 

 

先来实例配置，按照网上教程实现clock时钟：

 

clock.java  #pojo文件

package com;

/**
 * Created by fdd on 2017/4/10.
 */
public class Clock {

    private int hour;
    private int minute;
    private int second;

    public int getHour() {
        return hour;
    }
    public void setHour(int hour) {
        this.hour = hour;
    }
    public int getMinute() {
        return minute;
    }
    public void setMinute(int minute) {
        this.minute = minute;
    }
    public int getSecond() {
        return second;
    }
    public void setSecond(int second) {
        this.second = second;
    }

    @Override
    public String toString() {
        return hour + ":" + minute + ":" + second;
    }

}

 

clockTest.java  实例测试文件

package com;

/**
 * Created by fdd on 2017/4/10.
 */
import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
public class ClockTest {

    public static void main(String[] args) {
        KieServices ks = KieServices.Factory.get();
        KieContainer kContainer = ks.getKieClasspathContainer();
        KieSession kSession = kContainer.newKieSession("session-clock");
        kSession.insert(new Clock());
        kSession.fireAllRules();
        kSession.dispose();

    }


}

 

配置文件clock.drl

package com.ibm.clock
import com.Clock

rule "run"
    salience 1
    when
        c: Clock(!(minute == 1 && second == 1))
    then
        System.out.println(c);
        Thread.sleep(1000);
        c.setSecond(c.getSecond() + 1);
        update(c);
end

rule "second"
    salience 2
    when
        c: Clock(second == 2);
    then
        c.setMinute(c.getMinute() + 1);
        c.setSecond(0);
        update(c);
end

rule "minute"
    salience 3
    when
        c: Clock(minute == 60)
    then
        c.setHour(c.getHour() + 1);
        c.setMinute(0);
        update(c);
end

 

默认的kmodule.xml   API默认读取路径为META-INF/kmodule.xml

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

 

maven配置文件

<dependencies>
        <!-- https://mvnrepository.com/artifact/org.kie/kie-api -->
        <dependency>
            <groupId>org.kie</groupId>
            <artifactId>kie-api</artifactId>
            <version>6.0.0.CR1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.drools/drools-compiler -->
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-compiler</artifactId>
            <version>6.0.0.CR1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.drools/drools-core -->
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-core</artifactId>
            <version>6.0.0.CR1</version>
        </dependency>


    </dependencies>