DRL Examples

curl -sL https://raw.githubusercontent.com/aletyx-labs/kie-10.0.0-sandbox/refs/heads/main/docker-compose.yaml | docker compose -f - up

package ai.aletyx.model;

public class Order {
    private int itemsCount;
    private double total;
    private int deliverInDays;

    public Order() {
    }

    public Order(int itemsCount, double total, int deliverInDays) {
        this.itemsCount = itemsCount;
        this.total = total;
        this.deliverInDays = deliverInDays;
    }

    // Getters and setters
    public int getItemsCount() {
        return itemsCount;
    }

    public void setItemsCount(int itemsCount) {
        this.itemsCount = itemsCount;
    }

    public double getTotal() {
        return total;
    }

    public void setTotal(double total) {
        this.total = total;
    }

    public int getDeliverInDays() {
        return deliverInDays;
    }

    public void setDeliverInDays(int deliverInDays) {
        this.deliverInDays = deliverInDays;
    }
}

package ai.aletyx.model;

public class Charge {
    private double amount;

    public Charge() {
    }

    public Charge(double amount) {
        this.amount = amount;
    }

    public double getAmount() {
        return amount;
    }

    public void setAmount(double amount) {
        this.amount = amount;
    }

    @Override
    public String toString() {
        return "Shipping charge: $" + amount;
    }
}

shipping-rules-app/
├── pom.xml
└── src/
    └── main/
        ├── java/
        │   └── ai/
        │       └── aletyx/
        │           ├── model/
        │           │   ├── Order.java
        │           │   └── Charge.java
        │           └── ShippingChargesApp.java
        └── resources/
            └── rules/
                └── ShippingCharges.drl.xlsx

<?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>ai.aletyx</groupId>
    <artifactId>shipping-rules-app</artifactId>
    <version>1.0.0</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <drools.version>10.0.0</drools.version>
    </properties>

    <dependencies>
        <!-- Drools Dependencies -->
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-engine</artifactId>
            <version>${drools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-xml-support</artifactId>
            <version>${drools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-ruleunits-engine</artifactId>
            <version>${drools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-decisiontables</artifactId>
            <version>${drools.version}</version>
        </dependency>

        <!-- Logging -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.11</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <mainClass>ai.aletyx.ShippingChargesApp</mainClass>
                        </manifest>
                    </archive>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

package ai.aletyx;

import ai.aletyx.model.Charge;
import ai.aletyx.model.Order;
import org.drools.ruleunits.api.RuleUnitInstance;
import org.drools.ruleunits.api.RuleUnitProvider;
import org.drools.ruleunits.api.conf.RuleConfig;
import org.kie.api.resource.ResourceType;
import org.kie.internal.io.ResourceFactory;
import org.drools.io.ResourceFactoryService;
import org.kie.api.io.ResourceType;
import org.drools.ruleunits.api.RuleUnitInstance;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class ShippingChargesApp {
    public static void main(String[] args) {
        // Create a rule unit provider
        RuleUnitProvider ruleUnitProvider = RuleUnitProvider.get();

        // Create a rule unit data store
        ShippingUnit shippingUnit = new ShippingUnit();

        // Create a rule unit instance
        try (RuleUnitInstance<ShippingUnit> instance = ruleUnitProvider.createRuleUnitInstance(shippingUnit)) {
            // Load the decision table
            instance.getKieSession().getKieBase().newKieBuilder()
                    .add(ResourceFactory.newClassPathResource("rules/ShippingCharges.drl.xlsx"), ResourceType.DTABLE)
                    .build();

            // Interactive command line interface
            Scanner scanner = new Scanner(System.in);
            boolean running = true;

            while (running) {
                System.out.println("\n=== Shipping Charge Calculator ===");
                System.out.println("1. Calculate shipping charge");
                System.out.println("2. Exit");
                System.out.print("Enter choice: ");

                int choice = scanner.nextInt();
                scanner.nextLine(); // Consume newline

                switch (choice) {
                    case 1:
                        calculateShipping(scanner, shippingUnit, instance);
                        break;
                    case 2:
                        running = false;
                        break;
                    default:
                        System.out.println("Invalid choice!");
                }
            }

            System.out.println("Thank you for using the Shipping Charge Calculator!");
        }
    }

    private static void calculateShipping(Scanner scanner, ShippingUnit shippingUnit, RuleUnitInstance<ShippingUnit> instance) {
        System.out.print("Enter number of items: ");
        int itemsCount = scanner.nextInt();

        System.out.print("Enter order total: $");
        double total = scanner.nextDouble();

        System.out.println("Select delivery speed:");
        System.out.println("1. Next Day (1)");
        System.out.println("2. Second Day (2)");
        System.out.println("3. Standard (5)");
        System.out.print("Enter choice (1-3): ");
        int deliveryChoice = scanner.nextInt();

        int deliverInDays;
        switch (deliveryChoice) {
            case 1: deliverInDays = 1; break;
            case 2: deliverInDays = 2; break;
            case 3: deliverInDays = 5; break;
            default: deliverInDays = 5;
        }

        // Create the order
        Order order = new Order(itemsCount, total, deliverInDays);
        shippingUnit.getOrders().add(order);

        // Fire rules
        instance.fire();

        // Get results
        List<Charge> charges = new ArrayList<>(shippingUnit.getCharges());
        if (!charges.isEmpty()) {
            System.out.println("\nShipping charge: $" + charges.get(charges.size() - 1).getAmount());
        } else {
            System.out.println("\nNo shipping charge calculated.");
        }

        // Clear data for next calculation
        shippingUnit.getOrders().clear();
        shippingUnit.getCharges().clear();
    }

    // Rule Unit class
    public static class ShippingUnit {
        private final List<Order> orders = new ArrayList<>();
        private final List<Charge> charges = new ArrayList<>();

        public List<Order> getOrders() {
            return orders;
        }

        public List<Charge> getCharges() {
            return charges;
        }
    }
}

mvn clean package

java -jar target/shipping-rules-app-1.0.0-jar-with-dependencies.jar