大数据之Drools安装使用

一、Drools安装

1、导入相关依赖

<dependency>
   <groupId>org.drools</groupId>
    <artifactId>drools-compiler</artifactId>
    <version>7.23.0.Final</version>
</dependency>

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.2</version>
</dependency>      

2、添加lombok插件

二、入门案例

package cn.doitedu;

import cn.doitedu.pojo.Event;
import org.apache.commons.io.FileUtils;
import org.kie.api.io.ResourceType;
import org.kie.api.runtime.KieSession;
import org.kie.internal.utils.KieHelper;

import java.io.File;
import java.nio.charset.StandardCharsets;

public class DroolsDemo {

    public static void main(String[] args) throws Exception {

        //Drools的工具类，应用规则，窗口规则匹配的会话
        KieHelper kieHelper = new KieHelper();

        //将drools的规则文件转成字符串
        String droolsStr = FileUtils.readFileToString(new File("rules/first-demo.drl"), StandardCharsets.UTF_8);

        //添加规则
        kieHelper.addContent(droolsStr, ResourceType.DRL);

        //创建规则匹配的会话(将用户传入的数据和事先添加的规则进行匹配)
        KieSession kieSession = kieHelper.build().newKieSession();

        //传入用户的数据
        Event event = new Event("view", 4, false);

        kieSession.insert(event);
        //将数据应用所有规则
        kieSession.fireAllRules();

        System.out.println(event.isHit());


    }
}      

规则类文件first-demo.drl

dialect  "java"

import cn.doitedu.pojo.Event

rule "first-demo"
    when
       $e: Event(type == 'view' && count == 2)
    then
       System.out.println("666");
       $e.setHit(true);

end      

package cn.doitedu.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Event {

    private String type;

    private int count;

    private boolean hit;

}