我有下面的flink-keyedprocessfunction。我基本上是在尝试实现状态设计模式。

public AlertProcessor extends KeyedProcessFunction<Tuple2<String, String>, Event1, Event2> {

   private transient AlertState currentState;
   private transient AlertState activeAlertState;
   private transient AlertState noActiveAlertState;
   private transient AlertState resolvedAlertState;

   @Override
   public void open(Configuration parameters) {
      activeAlertState = new ActiveAlertState();
      noActiveAlertState = new NoActiveAlertState();
      resolvedAlertState = new ResolvedAlertState();
   }

   @Override
   public processElement(Event1 event1, Context ctx, Collector<Event2> out) throws Exception {

        // Would the below if condition work for multiple keys?
        if (currentAlertState == null) {
            currentAlertState = noActiveAlertState;
        }

        currentAlertState.handle(event1, out);
   }

   private interface AlertState {
        void handle(Event1 event1, Collector<Event2> out);
   } 

   private class ActiveAlertState implements AlertState {
       void handle(Event1 event1, Collector<Event2> out) {
           logger.debug("Moving to no alertState");

           // Do something and push some Event2 to out
           currentAlertState = resolvedActiveAlertState;
       }
   }

   private class NoActiveAlertState implements AlertState {
       void handle(Event1 event1, Collector<Event2> out) {
           logger.debug("Moving to no alertState");

           // Do something and push some Event2 to out
           currentAlertState = activeAlertState;
       }
   }

   private class ResolvedAlertState implements AlertState {

       void handle(Event1 event1, Collector<Event2> out) {
           logger.debug("Moving to no alertState");

           // Do something and push some Event2 to out
           currentAlertState = noActiveAlertState;
       }
   }

}

我的问题是-
流中的每个键是否有一个alertprocessor示例（或对象）？换句话说，currentalertstate对象是否每个键都是唯一的？或者该alertprocessor操作符的每个示例将有一个currentalertstate？
如果currentalertstate是每个操作符示例的值，那么这个代码将不会真正起作用，因为currentalertstate将被不同的键覆盖。我的理解正确吗？
我可以将currentalertstate存储在keyed状态，并为每个processelement（）调用初始化它。如果这样做，我就不需要在handle（）实现中将currentalertstate分配或设置为下一个状态，因为currentalertstate将根据flink状态进行初始化。
有没有更好的方法在flink中实现状态设计模式并减少创建的状态对象的数量？