Question

我正在尝试编写一条简单的规则，根据提供的症状来确定患者患感冒的可能性。每当提供的症状之一与感冒中出现的症状匹配时，它都会通过将初始0加1来检查感冒的所有可能症状。最后，将总值除以可能的感冒症状的总数。这是我第一次编写规则，因此，如果您认为我应该以不同的方式制定规则，那么我也会提出任何建议。

rule "Cold check"
    when
        $p: DoctorsAppointment() and //doctor's appointment which contains symptoms (symptoms are modelled as enumeration) that patient has
        $b: HashMap(String, Double) //hashmap which contains all diseases in the form key="disease name", value=0.0 initially.
    then
        for(Symptom s : $p.getSymptoms()) {
            if(s==Symptom.RUNNING_NOSE) {
                $b.put("cold", ((Double) $b.get("cold")) + 1.0);
            }
            else if(s==Symptom.SORE_THROAT) {
                $b.put("cold", ((Double) $b.get("cold")) + 1.0);
            }
            else if(s==Symptom.HEADACHE) {
                $b.put("cold", ((Double) $b.get("cold")) + 1.0);
            }
            else if(s==Symptom.SNEEZING) {
                $b.put("cold", ((Double) $b.get("cold")) + 1.0);
            }
            else if(s==Symptom.COUGHING) {
                $b.put("cold", ((Double) $b.get("cold")) + 1.0);
            }
        }
        $b.put("cold", ((Double) $b.get("cold"))/6);
end

我收到以下错误：

[dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.RuntimeException: Error evaluating constraint 'String' in [Rule "Cold check" in drules.drl]] with root cause

java.lang.ClassCastException: java.lang.Class cannot be cast to java.lang.Boolean

Drools错误：在[drules.drl中的规则“ Cold check”]中评估约束'String'时出错

0 个答案: