Esper规则语言:从模式返回类数据字段

Question

我有下面的规则，当心率保持在160以上5分钟时就会触发。

EPStatement cepStatementRule3 = cepRule.createEPL("context PartitionByMacHeartRate "
                + "select * from pattern[every(HeartRate(heartrate > 160) "
                + "-> (timer:interval(5 min) "
                + "and not HeartRate(heartrate<=160)))]");
        cepStatementRule3.addListener(new rule3Listener());

我的HeartRate类有以下字段：

int heartrate;
String heartratesTimestamp;
String macAddress;

我想要的是能够在我的macAddress中获得ruleListener。然而，这将返回一个空的hashmap。因此，我的问题是如何返回macAddress of HeartRate？

Answer 1

模式保留并返回标记的事件，即这样做：

// we assign the 'h' tag to the first event and the engine now retains that
// the select clause could use "h.macAddress as macAddress", for example
...every(h=HeartRate(...