Question

我将两个事实插入到我的drools会话中。我想查看以下内容：

（shipment1！= null＆amp;＆amp; shipment1.shipToCustomerNo == waypoint1.shipToNumber）|| shipment1 == null

如何在基于guvnor web的决策表中添加此条件？我尝试过使用谓词，而waypoint1和shipment1是成功插入会话的绑定变量。如果我使用谓词并添加上面的内容，我的测试用例工作正常，但是当我在我的Java应用程序中实际运行这些规则时，即使数据是等效的，条件也不会评估为真。我尝试了很多不同的方法来构建这个查询。以下是生成的来源：

//from row number: 1
rule "Row 1 Arrive Destination"
    salience 3
    activation-group "arrive-destination"
    dialect "mvel"
    when
        waypoint1 : Waypoint( type == "Destination" )
        clm1 : CarLocationMessage( sightCode == "Z" , loaded == true )
        shipment1 : Shipment( eval( (shipment1 != null && shipment1.shipToCustomerNo == waypoint1.shipToNumber) || shipment1 == null ))
    then
        TripEventRuleResult tripEventRuleResult1 = new TripEventRuleResult();
        tripEventRuleResult1.setEventType( "Arrive" );
        insert( tripEventRuleResult1 );
end

Answer 1

如果我正确理解了您的域名和问题描述，您应该可以像这样执行规则。

//from row number: 1
rule "Row 1 Arrive Destination"
    salience 3
    activation-group "arrive-destination"
    dialect "mvel"
    when
        waypoint1 : Waypoint( type == "Destination" )
        clm1 : CarLocationMessage( sightCode == "Z" , loaded == true )
        Shipment( shipToCustomerNo == waypoint1.shipToNumber) or
        not Shipment()
    then
        TripEventRuleResult tripEventRuleResult1 = new TripEventRuleResult();
        tripEventRuleResult1.setEventType( "Arrive" );
        insert( tripEventRuleResult1 );
end

简而言之，您不需要对Shipment对象进行空检查。它要么在工作记忆中，要么不在工作记忆中

如何在guvnor web决策表中检查等价？

1 个答案: