JarCastingfriendly-drools
Drools engine friendly wrapper
Features
- User can load an external drools file into the rule engine to run
- User can load an external text string as drool rules into the rule engine to run
- User can load external domain specific language (DSL) files or text string
- user can load external decision table specified in external excel files
Install
Add the following dependency to your POM file:
<dependency>
<groupId>com.github.chen0040</groupId>
<artifactId>friendly-drools</artifactId>
<version>1.0.1</version>
</dependency>
Usage
The sample codes can be found in the src/test/java folder.
Simple example of loading a an external text string as drool rules to run
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
String ruleContent = FileUtils.readToEnd("tutorials/customer-functions.drl");
ruleRunner.addRules("tutorials/customer-functions.drl", ruleContent);
ruleRunner.buildKnowledgeSession();
Customer customer = new Customer(1L, "Jack", Customer.Category.SILVER);
ruleRunner.insert(customer);
ruleRunner.setGlobal("globalList", new ArrayList<>());
ruleRunner.fireAllRules();
List<String> globalList = ruleRunner.getGlobal("globalList", List.class);
globalList.forEach(c -> logger.info("customer: {}", c));
Where tutorials/customer-functions.drl is a simple drools file containing the following content:
package tutorials;
import function com.github.chen0040.drools.tutorials.CustomerUtils.formatCustomer;
import com.github.chen0040.drools.tutorials.Customer;
import java.util.List;
global List globalList;
rule "Prepare customers list"
when
$c: Customer()
then
globalList.add(formatCustomer($c));
end
Load Drools File from resources folder
The following codes loads the anomaly detection rules for customer orders from drools files in the src/resources/tutorials folder:
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addClassPathRuleFile("tutorials", "tutorials/classify-item-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials", "tutorials/classify-customer-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials", "tutorials/coupon-creation-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials", "tutorials/coupon-execution-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials", "tutorials/order-discount-rules.drl");
ruleRunner.buildKnowledgeSession();
Order o = ModelFactory.getOrderWithFiveHighRangeItems();
ruleRunner.insert(o.getCustomer());
for(int i=0; i < o.getOrderLines().size(); ++i) {
ruleRunner.insert(o.getOrderLines().get(i));
ruleRunner.insert(o.getOrderLines().get(i).getItem());
}
ruleRunner.insert(o);
int fired = ruleRunner.fireAllRules();
// We have 5 Items that are categorized -> 5 rules were fired
// We have 1 Customer that needs to be categorized -> 1 rule fired
// We have just one order with all HIGH RAnge items -> 1 rule fired
// One Coupon is created for the SILVER Customer -> 1 rule fired
// One Coupon is executed after its creation -> 1 rule fired
logger.info("rules fired: {}", fired);
assertThat(fired).isEqualTo(9);
assertThat(o.getCustomer().getCategory()).isEqualTo(Customer.Category.SILVER);
assertThat(o.getDiscount()).isNotNull();
for(int i=0; i < o.getOrderLines().size(); ++i) {
assertThat(o.getOrderLines().get(i).getItem().getCategory()).isEqualTo(Item.Category.HIGH_RANGE);
}
List<Coupon> coupons = ruleRunner.getFacts(Coupon.class);
logger.info("orders: {}", ruleRunner.getFacts(Order.class).size());
logger.info("customers: {}", ruleRunner.getFacts(Customer.class).size());
assertThat(coupons.size()).isEqualTo(1);
Load Drools File from file disk
The following codes loads the anomaly detection rules for customer orders which are stored in the folder /tmp/tutorials:
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addClassPathRuleFile("tutorials/classify-item-rules.drl", "/tmp/tutorials/classify-item-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials/classify-customer-rules.drl", "/tmp/tutorials/classify-customer-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials/coupon-creation-rules.drl", "/tmp/tutorials/coupon-creation-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials/coupon-execution-rules.drl", "/tmp/tutorials/coupon-execution-rules.drl");
ruleRunner.addClassPathRuleFile("tutorials/order-discount-rules.drl", "/tmp/tutorials/order-discount-rules.drl");
ruleRunner.buildKnowledgeSession();
Order o = ModelFactory.getOrderWithFiveHighRangeItems();
ruleRunner.insert(o.getCustomer());
for(int i=0; i < o.getOrderLines().size(); ++i) {
ruleRunner.insert(o.getOrderLines().get(i));
ruleRunner.insert(o.getOrderLines().get(i).getItem());
}
ruleRunner.insert(o);
int fired = ruleRunner.fireAllRules();
// We have 5 Items that are categorized -> 5 rules were fired
// We have 1 Customer that needs to be categorized -> 1 rule fired
// We have just one order with all HIGH RAnge items -> 1 rule fired
// One Coupon is created for the SILVER Customer -> 1 rule fired
// One Coupon is executed after its creation -> 1 rule fired
logger.info("rules fired: {}", fired);
assertThat(fired).isEqualTo(9);
assertThat(o.getCustomer().getCategory()).isEqualTo(Customer.Category.SILVER);
assertThat(o.getDiscount()).isNotNull();
for(int i=0; i < o.getOrderLines().size(); ++i) {
assertThat(o.getOrderLines().get(i).getItem().getCategory()).isEqualTo(Item.Category.HIGH_RANGE);
}
List<Coupon> coupons = ruleRunner.getFacts(Coupon.class);
logger.info("orders: {}", ruleRunner.getFacts(Order.class).size());
logger.info("customers: {}", ruleRunner.getFacts(Customer.class).size());
assertThat(coupons.size()).isEqualTo(1);
Load Excel Decision Table
The following codes how to load rules from external excel decision table.
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
InputStream is = new FileInputStream("tutorials/classify-customer.xls");
String rules = ruleRunner.expandDecisionTable(is, DecisionTableInputType.XLS, null);
logger.info("rules: \n{}", rules);
ruleRunner.addDecisionTable("classify-customer.xls", is, DecisionTableInputType.XLS, null);
ruleRunner.buildKnowledgeSession();
for(int age = 16; age < 45; ++age){
ruleRunner.insert(ModelFactory.getCustomerWithAge(age));
}
ruleRunner.fireAllRules();
Load Dsl (Domain-Specific-Language) File
The following codes show how to load domain specific language (DSL) files as well as drools files written using DSL.
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
String dslContent = FileUtils.readToEnd("tutorials/classify-customer.dsl");
String dslrContent = FileUtils.readToEnd("tutorials/classify-customer-rules.dslr");
String drlContent = RuleEngine.expandDSLRules(dslContent, dslrContent);
logger.info("expanded drl: \n{}", drlContent);
ruleRunner.addDsl("tutorials/classify-customer.dsl", dslContent);
ruleRunner.addDslRules("tutorials/classify-customer-rules.dslr", dslrContent);
ruleRunner.buildKnowledgeSession();
for(int age = 21; age <= 31; ++age) {
ruleRunner.insert(ModelFactory.getCustomerWithAge(age));
}
ruleRunner.fireAllRules();
CEP
The following codes show how to use the rule engine for complex event processing by loading the cep rule files from external text string.
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addRules("tutorials/transaction-cep-rules.drl", FileUtils.readToEnd("tutorials/transaction-cep-rules.drl"));
ruleRunner.enableEventStreaming();
ruleRunner.buildKnowledgeSession();
long now = new Date().getTime();
for(int i=0; i < 11; ++i) {
ruleRunner.insert(new TransactionEvent(1L, 100.0, new Date(now - 10000 + 1000 * i), 100L));
}
ruleRunner.insert(new TransactionEvent(1L, 1010.0, new Date(now), 100L));
ruleRunner.fireAllRules();
CEP with window declaration
The following codes show how to perform CEP with window declaration:
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addRules("tutorials/heartbeat-cep-rules.drl", FileUtils.readToEnd("tutorials/heartbeat-cep-rules.drl"));
ruleRunner.enableEventStreaming();
ruleRunner.buildKnowledgeSession();
long now = new Date().getTime();
for(int i=0; i < 11; ++i) {
ruleRunner.getSession().getEntryPoint("heart beat monitor").insert(new HeartBeat(new Date(now - 10000 + 5 * i), 100L));
}
ruleRunner.getSession().getEntryPoint("heart beat monitor").insert(new HeartBeat(new Date(now), 100L));
ruleRunner.fireAllRules();
Load drools that interact with java delclared functions
The following codes shows how to work with drool file that access the java declared functions:
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addRules("tutorials/order-total-rules.drl", FileUtils.readToEnd("tutorials/order-total-rules.drl"));
ruleRunner.addRules("tutorials/order-functions.drl", FileUtils.readToEnd("tutorials/order-functions.drl"));
ruleRunner.buildKnowledgeSession();
Customer customer1 = new Customer();
customer1.setCustomerId(1L);
Order customer1Order = ModelFactory.getPendingOrderWithTotalValueGreaterThan10000(customer1);
Customer customer2 = new Customer();
customer2.setCustomerId(2L);
Order customer2Order = ModelFactory.getPendingOrderWithTotalValueLessThan10000(customer1);
OrderService orderService = new OrderServiceImpl();
orderService.save(customer1Order);
orderService.save(customer2Order);
ruleRunner.insert(customer1);
ruleRunner.insert(customer2);
ruleRunner.setGlobal("biggestOrder", new BiggestOrder());
ruleRunner.setGlobal("orderService", orderService);
ruleRunner.fireAllRules();
BiggestOrder biggestOrder = ruleRunner.getGlobal("biggestOrder", BiggestOrder.class);
logger.info("biggest order: {}", biggestOrder.getObject());
The content of tutorials/order-functions.drl is shown below:
package tutorials;
import accumulate com.github.chen0040.drools.tutorials.BiggestOrderFunction biggestOrder
import com.github.chen0040.drools.tutorials.BiggestOrder;
global BiggestOrder biggestOrder;
rule "Find Biggest Order"
when
$bigO: Order() from accumulate(
$o: Order(),
biggestOrder($o)
)
then
biggestOrder.setObject($bigO);
end
Where BiggestOrderFunction is defined in the java code instead:
import org.kie.api.runtime.rule.AccumulateFunction;
import java.io.*;
public class BiggestOrderFunction implements AccumulateFunction {
public static class Context implements Externalizable {
public Order maxOrder = null;
public double maxTotal = - Double.MAX_VALUE;
@Override public void writeExternal(ObjectOutput out) throws IOException {
}
@Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
}
}
@Override public Serializable createContext() {
return new Context();
}
@Override public void init(Serializable serializable) throws Exception {
}
@Override public void accumulate(Serializable context, Object value) {
Context c = (Context) context;
Order order = (Order) value;
double discount = order.getDiscount() == null ? 0 : order.getDiscount().getPercentage();
double orderTotal = order.getTotal() - (order.getTotal() * discount);
if(orderTotal > c.maxTotal) {
c.maxTotal = orderTotal;
c.maxOrder = order;
}
}
@Override public void reverse(Serializable serializable, Object o) throws Exception {
}
@Override public Object getResult(Serializable context) throws Exception {
return ((Context)context).maxOrder;
}
@Override public boolean supportsReverse() {
return false;
}
@Override public Class<?> getResultType() {
return Order.class;
}
@Override public void writeExternal(ObjectOutput out) throws IOException {
}
@Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
}
}
Event Listeners
The sample code below show how to use event listener:
StatefulRuleEngine ruleRunner = new StatefulKieRuleEngine();
ruleRunner.addRules("tutorials/order-total-rules.drl", FileUtils.readToEnd("tutorials/order-total-rules.drl"));
ruleRunner.addRules("tutorials/anomaly-detection-rules.drl", FileUtils.readToEnd("tutorials/anomaly-detection-rules.drl"));
ruleRunner.addRules("tutorials/anomaly-detection-result-queries.drl", FileUtils.readToEnd("tutorials/anomaly-detection-result-queries.drl"));
ruleRunner.buildKnowledgeSession();
Customer customer1 = new Customer();
customer1.setCustomerId(1L);
Order customer1Order = ModelFactory.getPendingOrderWithTotalValueGreaterThan10000(customer1);
Customer customer2 = new Customer();
customer2.setCustomerId(2L);
Order customer2Order = ModelFactory.getPendingOrderWithTotalValueLessThan10000(customer1);
OrderService orderService = new OrderServiceImpl();
orderService.save(customer1Order);
orderService.save(customer2Order);
AuditService auditService = new AuditServiceImpl();
ruleRunner.insert(customer1);
ruleRunner.insert(customer2);
ruleRunner.setGlobal("orderService", orderService);
ruleRunner.setGlobal("amountThreshold", 10000.00);
ruleRunner.setGlobal("results", new HashSet<>());
ruleRunner.setGlobal("auditService", auditService);
ruleRunner.registerChannel("audit-channel", o -> logger.info("receive from channel: {}", o));
ruleRunner.getSession().addEventListener(new RuleRuntimeEventListener() {
@Override public void objectInserted(ObjectInsertedEvent objectInsertedEvent) {
}
@Override public void objectUpdated(ObjectUpdatedEvent objectUpdatedEvent) {
}
@Override public void objectDeleted(ObjectDeletedEvent objectDeletedEvent) {
}
});
ruleRunner.getSession().addEventListener(new AgendaEventListener() {
@Override public void matchCreated(MatchCreatedEvent matchCreatedEvent) {
}
@Override public void matchCancelled(MatchCancelledEvent matchCancelledEvent) {
}
@Override public void beforeMatchFired(BeforeMatchFiredEvent beforeMatchFiredEvent) {
logger.info("before match fired: {}", beforeMatchFiredEvent.getMatch().getRule().getName());
}
@Override public void afterMatchFired(AfterMatchFiredEvent afterMatchFiredEvent) {
logger.info("after match fired: {}", afterMatchFiredEvent.getMatch().getRule().getName());
}
@Override public void agendaGroupPopped(AgendaGroupPoppedEvent agendaGroupPoppedEvent) {
}
@Override public void agendaGroupPushed(AgendaGroupPushedEvent agendaGroupPushedEvent) {
}
@Override public void beforeRuleFlowGroupActivated(RuleFlowGroupActivatedEvent ruleFlowGroupActivatedEvent) {
}
@Override public void afterRuleFlowGroupActivated(RuleFlowGroupActivatedEvent ruleFlowGroupActivatedEvent) {
}
@Override public void beforeRuleFlowGroupDeactivated(RuleFlowGroupDeactivatedEvent ruleFlowGroupDeactivatedEvent) {
}
@Override public void afterRuleFlowGroupDeactivated(RuleFlowGroupDeactivatedEvent ruleFlowGroupDeactivatedEvent) {
}
});
ruleRunner.fireAllRules();