如何在guvnor web决策表中检查等价性

Question

我在流口水的会话中插入了两个事实。我想检查以下内容：

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

如何在基于网络的决策表中添加此条件？我尝试过使用谓词，waypoint1和shipment1是绑定变量，它们正在成功插入会话中。如果我使用谓词并添加上面的内容，我的测试用例就可以正常工作，但当我在java应用程序中实际运行这些规则时，即使数据是等效的，条件也永远不会计算为true。我已经尝试了许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和问题描述，您应该能够执行这样的规则。

//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null检查。它在或不在工作内存中