drools 的一個小demo

直接上代碼:

第一步，maven引入相關包

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <drools.version>6.1.0.Final</drools.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>

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

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>      

第二步，編寫一個規則檔案:

//包名
package test
import com.example.demo.drools.test.Stu;

//rule 就是三大塊中的規則體，以rule開頭，以end 結尾，每個規則檔案可以包含多個rule。規則體分為三個部分，LHS RHS 屬性 三大部分
//LHS：條件部分又被稱之為 LeftHand Side，簡稱為 LHS，在一個規則當中 when 與 then 中間的部分就是 LHS 部分。
//在 LHS 當中，可以包含 0~n 個條件，如果 LHS 部分沒空的話，那麼引擎會自動添加一個eval(true)的條件，由于該條件總是傳回 true，是以 LHS 為空的規則總是傳回 true。
//RHS：結果部分又被稱之為 RightHand Side，簡稱為 RHS，在一個規則當中 then後面部分就是 RHS，隻有在 LHS 的所有條件都滿足時 RHS 部分才會執行。

rule "rule1"
    salience 1
        when
            $stu:Stu(age>30)//這裡就是LHS
        then
            System.out.println("age>30歲的人:"+$stu.getName());//RHS
end


rule "rule2"
    salience 2
    when
         $stu:Stu(gender=="male",age>25)
    then
        System.out.println("性别為男,age>25歲的人:"+$stu.getName());
     end


rule "rule3"
     salience 3
     when
        $stu:Stu(getName()=="張三")
        then
         System.out.println("名字為:"+$stu.getName());
         end      

第三步：測試代碼

package com.example.demo.drools.test;

import org.drools.core.io.impl.ClassPathResource;
import org.kie.api.io.ResourceType;
import org.kie.internal.KnowledgeBase;
import org.kie.internal.KnowledgeBaseFactory;
import org.kie.internal.builder.KnowledgeBuilder;
import org.kie.internal.builder.KnowledgeBuilderFactory;
import org.kie.internal.definition.KnowledgePackage;
import org.kie.internal.runtime.StatefulKnowledgeSession;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * Created by ming on 2018/5/24.
 */
public class Test {

    public static void main(String[] args) {
        KnowledgeBuilder kb = KnowledgeBuilderFactory.newKnowledgeBuilder();
        kb.add(new ClassPathResource("test.drl"), ResourceType.DRL);
        Collection<KnowledgePackage> collection = kb.getKnowledgePackages();
        KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase();
        knowledgeBase.addKnowledgePackages(collection);
        StatefulKnowledgeSession statefulSession = knowledgeBase.newStatefulKnowledgeSession();
        List<Stu> list = getStus();
        for (Stu stu : list) {
            statefulSession.insert(stu);
        }
        statefulSession.fireAllRules();
        statefulSession.dispose();
        System.out.println("end....");
    }

    public static List<Stu> getStus() {
        List<Stu> stus = new ArrayList<>();
        stus.add(new Stu("張三", 16, "male"));
        stus.add(new Stu("huhu", 18, "male"));
        stus.add(new Stu("王五", 32, "male"));
        stus.add(new Stu("張紅", 23, "female"));
        stus.add(new Stu("李四", 35, "male"));
        stus.add(new Stu("張小雅", 31, "female"));
        return stus;
    }
}      

package com.example.demo.drools.test;

/**
 * Created by Administrator on 2018/5/24.
 */
public class Stu {

    private String name;

    private int age;

    private String gender;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Stu(String name,int age,String gender){
        this.name=name;
        this.age=age;
        this.gender=gender;
    }

}