《Drools7.0.0.Final规则引擎教程》第2章 追溯Drools5的使用

<?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.secbro</groupId>
    <artifactId>drools-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <drools-version>7.0.0.Final</drools-version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-compiler</artifactId>
            <version>${drools-version}</version>
        </dependency>
    </dependencies>
</project>

package com.secbro.drools.model;
/**
 * 产品类
 * Created by zhuzs on 2017/7/4.
 */
public class Product {
    /**
     * 钻石
     */
    public static final String DIAMOND = "0";
    /**
     * 黄金
     */
    public static final String GOLD = "1";
    private String type;
    private int discount;
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public int getDiscount() {
        return discount;
    }
    public void setDiscount(int discount) {
        this.discount = discount;
    }
}

package com.rules
import com.secbro.drools.model.Product
rule Offer4Diamond
    when
        productObject : Product(type == Product.DIAMOND)
    then
        productObject.setDiscount(15);
    end
rule Offer4Gold
    when
        productObject: Product(type == Product.GOLD)
    then
        productObject.setDiscount(25);
    end

package com.secbro.drools;
import com.secbro.drools.model.Product;
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.io.ResourceFactory;
import org.kie.internal.runtime.StatefulKnowledgeSession;
import java.util.Collection;
/**
 * Created by zhuzs on 2017/7/4.
 */
public class Drools5xTest {
    public static void main(String[] args) {
        Drools5xTest test = new Drools5xTest();
        test.oldExecuteDrools();
    }
    private void oldExecuteDrools() {
        KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
        kbuilder.add(ResourceFactory.newClassPathResource("com/rules/Rules.drl",
                this.getClass()), ResourceType.DRL);
        if (kbuilder.hasErrors()) {
            System.out.println(kbuilder.getErrors().toString());
        }
        Collection<KnowledgePackage> pkgs = kbuilder.getKnowledgePackages();
        // add the package to a rulebase
        KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
        // 将KnowledgePackage集合添加到KnowledgeBase当中
        kbase.addKnowledgePackages(pkgs);
        StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
        Product product = new Product();
        product.setType(Product.GOLD);
        ksession.insert(product);
        ksession.fireAllRules();
        ksession.dispose();
        System.out.println("The discount for the product " + product.getType()
                + " is " + product.getDiscount()+”%”);
    }
}