Spring 将双值设置为0

下面是我的fireRules（）方法，其中orderresponseVO对象被插入到会话中，以基于totalorderprice计算收益

private void fireRules(ProductResponseVO orderresponseVO,OrderDetailsVO orderdetailsVO{
orderresponseVO.setDiscounts(null);
FactHandle fact= vbDiscSession.insert(orderresponseVO);
vbDiscSession.fireAllRules();
calculateDiscounts(orderresponseVO);
orderdetailsVO.setEarnings(orderresponseVO.getEarnings());
orderdetailsVO.setInvoiceAmount(orderresponseVO.getInvoice());
vbDiscSession.retract(fact);
}

这是.drl文件 编写了2条规则，根据totalordervalue和一条默认规则计算添加折扣，该规则每次打印totalorderprice时都会被触发

        //created on: Mar 21, 2014
package com.mit.rules.vb
import com.mit.vb.admin.order.bean.ProductResponseVO
import com.mit.vb.admin.order.bean.DiscountVO
import com.mit.vb.admin.order.bean.OrderResponseVO

//list any import classes here.
dialect "mvel"



//declare any global variables here
rule "Discount"
salience 100    
no-loop true
   when
       $responseVO: ProductResponseVO(totalorderprice > 250)
                //conditions
            then
                //actions
                 $responseVO.addDiscount(new DiscountVO("test",$responseVO.totalorderprice*0.35));

        end

        rule "Discount special"
            salience 50    
            no-loop true
            //include attributes such as "salience" here...
            when
                $responseVO: ProductResponseVO(totalorderprice >= 500)
                //conditions
            then
                $responseVO.addDiscount(new DiscountVO(" You made it ",$responseVO.totalorderprice*0.10));
                //actions
        end

        rule "Print before every rule" salience 150
        when
               $responseVO: ProductResponseVO()       
        then
            //   System.out.println( " -------------- " + $cpSellerDetails.cpInfoBean.name);
                System.out.println( " -------------- " + $responseVO.totalorderprice);
        end

根据totalordervalue添加新折扣VO

下面是addDiscount（）方法

这里的问题是，无论何时使用drl文件中的addDiscount（）添加DiscountVo，DiscountVo中的构造函数都会将第二个参数设置为0，即使实际计算不同。 我已交叉检查以验证折扣值。即使不为零，计算也设置为零

package com.mit.rules.vb

import com.mit.vb.admin.order.bean.ProductResponseVO
import com.mit.vb.admin.order.bean.DiscountVO


//list any import classes here.
dialect "mvel"



//declare any global variables here
rule "Discount"
    salience 100    
    no-loop true
    when
        $responseVO: ProductResponseVO(totalorderprice > 250)
        //conditions
    then
        //actions
        $mulvalue=0.35;
        $total=$responseVO.totalorderprice*$mulvalue;
         System.out.println( " Discount " + $total);
         $responseVO.addDiscount(new DiscountVO("test", $total));

end

rule "Discount special"
    salience 50    
    no-loop true
    //include attributes such as "salience" here...
    when
        $responseVO: ProductResponseVO(totalorderprice >= 500)
        //conditions
    then
        $mulvalue=0.10;
        $total=$responseVO.totalorderprice*$mulvalue;
        System.out.println( " Discount special " + $total);
        $responseVO.addDiscount(new DiscountVO(" You made it ",$total));
        //actions
end

rule "Print before every rule" salience 150
when
       $responseVO: ProductResponseVO()       
then
    //   System.out.println( " -------------- " + $cpSellerDetails.cpInfoBean.name);
        System.out.println( " -------------- " + $responseVO.totalorderprice);
end

---

与其直接将乘法表达式传递给构造函数，不如将乘法常量0.35和0.10复制到一个变量$mulvalue，并将乘积存储在另一个变量$total中。这是可行的。但我不明白为什么直接乘法表达式不起作用。

我重复了您报告的问题。这是一个由int乘以double引起的mvel错误，我会尽快修复它。请注意，使用java方言，它确实可以正常工作。相反，如果出于某种原因，您需要使用mvel方言，我建议的最快解决方法是首先使用双精度：在您的情况下，使用0.35*$responseVO.totalorderprice按预期工作。

您如何得出结论，是DiscountTVo中的构造函数造成了损害？Java方法或构造函数无法“将参数设置为零”。如果折扣VO对象中的折扣值为零，则可能有其他原因，因为调用构造函数看起来没问题。是的，劳恩。问题不在构造函数中，而在.drl文件$responseVO.totalorderprice*0.35--->中的计算结果是0，而totalorderprice是408，但乘法结果是0。您使用的是哪个Drools版本？我的Drools版本是5.6.0.Final--launeWe也遇到了这个问题。您能告诉我们是否有问题跟踪参考？它是否在mvel 2.2.0最终版中固定？它在mvel 2.2.2.0最终版中固定。

public class DiscountVO implements Serializable {
    /**
     * 
     */
    private static final long serialVersionUID = 3440977389992293711L;
    private int orderid;
    private String discountName;
    private Double discountValue;
    private boolean isPercent=false;
    private Double discountPercent;

    public DiscountVO(String discountName,Double discountValue){
        this.discountName= discountName;
        this.discountValue=discountValue;
    }

package com.mit.rules.vb

import com.mit.vb.admin.order.bean.ProductResponseVO
import com.mit.vb.admin.order.bean.DiscountVO


//list any import classes here.
dialect "mvel"



//declare any global variables here
rule "Discount"
    salience 100    
    no-loop true
    when
        $responseVO: ProductResponseVO(totalorderprice > 250)
        //conditions
    then
        //actions
        $mulvalue=0.35;
        $total=$responseVO.totalorderprice*$mulvalue;
         System.out.println( " Discount " + $total);
         $responseVO.addDiscount(new DiscountVO("test", $total));

end

rule "Discount special"
    salience 50    
    no-loop true
    //include attributes such as "salience" here...
    when
        $responseVO: ProductResponseVO(totalorderprice >= 500)
        //conditions
    then
        $mulvalue=0.10;
        $total=$responseVO.totalorderprice*$mulvalue;
        System.out.println( " Discount special " + $total);
        $responseVO.addDiscount(new DiscountVO(" You made it ",$total));
        //actions
end

rule "Print before every rule" salience 150
when
       $responseVO: ProductResponseVO()       
then
    //   System.out.println( " -------------- " + $cpSellerDetails.cpInfoBean.name);
        System.out.println( " -------------- " + $responseVO.totalorderprice);
end