drools中then部分的写法(推荐)

package rules
import com.huan.drools.insertmethod.Fire
import com.huan.drools.insertmethod.Alarm
rule "insert_发生火灾时，往工作内存中插入告警对象"
    when
        $fire: Fire()
    then
        System.out.println("1、发生火灾时，往工作内存中插入告警对象");
        insert(new Alarm($fire));
end
rule "insert_当规则内存中存在告警对象，进行告警，然后删除火灾对象"
    when
        $fire: Fire()
        $alarm: Alarm( fire == $fire )
    then
        System.out.println("2、进行告警，然后删除对应的火灾对象");
end
rule "insert_检测告警对象是否还是存在-01"
    when
        Alarm()
    then
        System.out.println("3、insert 插入的告警对象还存在");
        // 删除工作内存中的Fire对象
        delete($fire);
end
rule "insert_检测告警对象不存在"
    when
        not Alarm()
    then
        System.out.println("3、insert 插入的告警对象不存在");
end

// 将火灾对象插入到工作内存中
kieSession.insert(new Fire());
// 只触发规则名称以 insert_ 开头的规则
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("insert_"));

package rules
import com.huan.drools.Fire
import com.huan.drools.Alarm
rule "insertLogical_发生火灾时，往工作内存中插入告警对象"
    when
        $fire: Fire()
    then
        System.out.println("1、发生火灾时，往工作内存中插入告警对象");
        insertLogical(new Alarm($fire));
end
rule "insertLogical_当规则内存中存在告警对象，进行告警，然后删除火灾对象"
    when
        $fire: Fire()
        $alarm: Alarm( fire == $fire )
    then
        System.out.println("2、进行告警，然后删除对应的火灾对象");
        delete($fire);
end
rule "insertLogical_检测告警对象是否还是存在-01"
    when
        Alarm()
    then
        System.out.println("3、insertLogical 插入的告警对象还存在");
end
rule "insertLogical_检测告警对象不存在"
    when
        not Alarm()
    then
        System.out.println("3、insertLogical 插入的告警对象不存在");
end

kieSession.insert(new Fire());
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("insertLogical_"));

package rules
import com.huan.drools.Fire
import com.huan.drools.Alarm
rule "update_当存在火灾对象时，设置一个火灾的名字"
    when
        $fire: Fire(name == null)
    then
        System.out.println("1、设置火灾名字");
        $fire.setName("大火灾");
        update($fire)
end
rule "update_当火灾对象存在名字时触发"
    when
        $fire: Fire(name != null)
    then
        System.out.println("2、火灾对象的名字为: "   $fire.getName());
end

kieSession.insert(new Fire());
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("update_"));

package rules
import com.huan.drools.Fire
import com.huan.drools.Alarm
rule "modify_当存在火灾对象时，设置一个火灾的名字"
    when
        $fire: Fire(name == null)
    then
        System.out.println("1、设置火灾名字");
        modify($fire){
            setName("大火灾")
        }
end
rule "modify_当火灾对象存在名字时触发"
    when
        $fire: Fire(name != null)
    then
        System.out.println("2、火灾对象的名字为: "   $fire.getName());
end

kieSession.insert(new Fire());
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("modify_"));

package rules
rule "drools_变量的使用"
    wh
        eval(true)
    then
        System.out.println("Match激活的当前触发规则: "   drools.getMatch());
        System.out.println("当前触发规则的名字: "   drools.getRule().getName());
        // System.out.println("终止规则执行fireUntilHalt(): "   drools.getKieRuntime().halt());
        // System.out.println("激活AgendaGroup组: "   drools.getKieRuntime().getAgenda().getAgendaGroup( "CleanUp" ).setFocus());
        System.out.println("获取所有全局变量: "   drools.getKieRuntime().getGlobals());
        // System.out.println("设置全局变量："    drools.getKieRuntime().setGlobal("username","huan"); );
        // System.out.println("获取查询结果："   drools.getKieRuntime().getQueryResults());
end

package rules
import com.huan.drools.Customer
import com.huan.drools.Car
rule "rule_extends_规则一"
    when
        $c: Customer(age > 60)
    then
        modify($c){
            setDiscount(0.9)
        }
        System.out.println("触发规则一：用户年龄>60岁，打0.9折");
end
// 规则二继承规则一的条件
rule "rule_extends_规则二" extends "rule_extends_规则一"
    when
        $car: Car()
    then
        modify($car){
            setFreeParking(true)
        }
        System.out.println("触发规则二：用户有车，免费停车");
end

Car car = new Car();
Customer customer = new Customer();
customer.setAge(65);
kieSession.insert(customer);
kieSession.insert(car);
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("rule_extends_"));

package rules
import com.huan.drools.Customer
import com.huan.drools.Car
rule "命名结果_rule"
    when
        $c: Customer(age > 60)
        do[giveDiscount] // 当上方的条件成立时执行 then [giveDiscount]
        $car: Car() // 此条件成立时，执行默认的 then
    then
        modify($car){
            setFreeParking(true)
        };
        System.out.println("用户有车，免费停车");
    then [giveDiscount]
        modify($c){
            setDiscount(0.9)
        };
        System.out.println("用户年龄>60岁，打0.9折");
end

Car car = new Car();
Customer customer = new Customer();
customer.setAge(65);
kieSession.insert(customer);
kieSession.insert(car);
kieSession.fireAllRules(new RuleNameStartsWithAgendaFilter("命名结果_"));

rule "if else-if"
    when
       $customer: Customer(age > 60) // 规则内存中存在Customer对象，并且age>60
        if($customer.getLevel() == 1) do[level1] // 用户的级别是1，执行then[level1],然后继续执行下方的条件
        else if ($customer.getLevel() == 2) break[level2] // 用户的级别是2，执行then[level2],不在执行下方的条件
        else do[levelOther] // 其他的level级别，执行then[levelOther],然后在执行下方的条件
        Car()
    then
        System.out.println("我执行了");
    then[level1]
        System.out.println("level1");
    then[level2]
        System.out.println("level2");
    then[levelOther]
        System.out.println("levelOther");
end