可能是你没有在open方法里从上下文获取mapstate
e.g.:
map = getRuntimeContext().getMapState(new MapStateDescriptor<xx,xx>(mapname, 
xx.class, xx.class))吗


-----邮件原件-----
发件人: 谌祖安 [mailto:[email protected]] 
发送时间: 2021年2月7日 星期日 16:25
收件人: user-zh <[email protected]>
主题: procesElement中每天数据都put 进入map,但下一条数据来时map都是空的咨询

您好!

重载procesElement方法,每条stream数据处理时,put数据进入map,后面每条数据处理时先判断是否在map中有相同的key值,无则新增后put进map,有则加工后put进map。
 在实际代码中发现,每次写入put后,map有数据,但处理下一条数据时,先从map读取数据,发现map已经为空。
请问是哪里写错了吗?   和   flink官网中     state.update(current);有什么不同吗?

以下为代码:
 private MapState<String, MicsTrainPractical> map;  //定义map
  @Override
public void processElement(MicsTrainPracticalDetail value, Context ctx, 
Collector<MicsTrainPractical> out) throws Exception {
       
        MicsTrainPractical current = map.get(value.getTrainNumber());        
         System.out.println(map.isEmpty());  // 
每次数据进来都发现map已经为空,不能保存前面数据进来时put的数据
        Long departTime = 
DateTimeUtils.convertToTimestampSecond(value.getDepartTime());
        Long arrivalTime = 
DateTimeUtils.convertToTimestampSecond(value.getArrivalTime());
        if (current == null) {   //如果map中没有获取到string相同的数据,则新建一条数据put进去
            MicsTrainPractical actual = new MicsTrainPractical();
            actual.setTrainId(value.getTrainNumber());
            actual.setCarId(value.getCarId());
            actual.setStartStationId(value.getStationId());
            actual.setStartPracticalArrivalTime(arrivalTime);
            actual.setEndPracticalArrivalTime(arrivalTime);
            actual.setStartPracticalDepartTime(departTime);
            actual.setEndPracticalDepartTime(departTime);
            actual.setEndStationId(value.getStationId());
            actual.setStopTime(0L);
            actual.setDs(value.getDs());
            actual.setIsInsert(true);
            actual.setTargetStationId(value.getTargetStationId());
            out.collect(actual);
            map.put(value.getTrainNumber(), actual);    //向map中写入数据
            return;
        } else {                   //如果map有获取到string相同的数据,则转换数据后写入map
            
            MicsTrainPractical actual = new MicsTrainPractical();
            actual.setTrainId(value.getTrainNumber());
            actual.setCarId(value.getCarId());
            actual.setStartStationId(current.getStartStationId());
            actual.setEndStationId(value.getStationId());
            
actual.setStartPracticalArrivalTime(current.getStartPracticalArrivalTime());
            
actual.setStartPracticalDepartTime(current.getStartPracticalDepartTime());
            actual.setEndPracticalArrivalTime(arrivalTime);
            actual.setEndPracticalDepartTime(departTime);
            actual.setStopTime(current.getStopTime() + Math.abs(departTime - 
arrivalTime));
            actual.setDs(value.getDs());
            actual.setIsInsert(false);
            actual.setTargetStationId(value.getTargetStationId());
            current.setEndStationId(actual.getEndStationId());
            
current.setEndPracticalDepartTime(actual.getEndPracticalDepartTime());
            
current.setEndPracticalArrivalTime(actual.getEndPracticalArrivalTime());
            current.setStopTime(actual.getStopTime());
            current.setIsInsert(actual.getIsInsert());

            MicsTrainSectionInfo trainSectionInfo = new MicsTrainSectionInfo();
            trainSectionInfo.setTrainId(actual.getTrainId());
            trainSectionInfo.setCarId(actual.getCarId());
            trainSectionInfo.setStartStationId(current.getEndStationId());
            trainSectionInfo.setEndStationId(actual.getEndStationId());
            trainSectionInfo.setDepartTime(current.getEndPracticalDepartTime());
            
trainSectionInfo.setArrivalTime(actual.getEndPracticalArrivalTime());

            map.put(value.getTrainNumber(), actual);
            out.collect(actual);
            ctx.output(outputTagSectionFlow, trainSectionInfo);
        }
    }




谌祖安
智能轨道交通业务群 / 产品事业部 / 开发经理
Intelligent RailTransportation BG /Development Manager
广东省广州市天河区新岑四路2号佳都智慧大厦
PCI Intelligence Building, No. 2 Xincen Fourth Road, Tianhe District, 
Guangzhou, Guangdong E [email protected] M 86-18680458868 www.pcitech.com

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