在flink项目中，我使用case类click。

case class click( date: LocalDateTime, stbId:String, channelId :Int)

这个类填充了数据集，并且在日期为Java8的情况下运行良好 java.time.LocalDateTime . 在Java7环境中切换到org.joda（version2.9）后，对数据集中click对象的调用没有像以前那样执行。对单击对象的日期字段的某些函数的访问 NullPointerExceptions . 这些函数的示例如下
getHourOfDay toString 我可以确保click类的date字段不为空。我怀疑joda时间库与kryo序列化的交互不好。请参阅joda datetime format cause null pointer error in spark rdd functions或npe in spark with joda datetime in the flink api there is org.apache.flink.api.java.typeutils.runtime.kryo.serializers with the static method registerJodaTime . 这似乎是相关的。我只是简单地试了一下

import  org.apache.flink.api.common._
import org.apache.flink.api.java.typeutils.runtime.kryo._
Serializers.registerJodaTime(new ExecutionConfig)

这还不够。我说的对吗？如何使用java.typeutils.runtime.kryo？
flink使用的版本：0.9.1。斯卡拉：2.10焦达时间2.9
跟进：以下是建议添加的代码（感谢fabian和robert）

val env = ExecutionEnvironment.getExecutionEnvironment
//import  org.apache.flink.api.common._
import org.apache.flink.api.java.typeutils.runtime.kryo._
Serializers.registerJodaTime(env.getConfig)

在嵌入式执行的日志文件中，我可以找到以下相关部分：

16:44:53,998 INFO  org.apache.flink.api.java.ExecutionEnvironment                - The job has 2 registered types and 0 default Kryo serializers
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo types: 
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo with Serializers types: 
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo with Serializer Classes types: Entry{k=class org.joda.time.DateTime, v=class de.javakaffee.kryoserializers.jodatime.JodaDateTimeSerializer},Entry{k=class org.joda.time.Interval, v=class de.javakaffee.kryoserializers.jodatime.JodaIntervalSerializer}
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo default Serializers: 
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo default Serializers Classes 
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered POJO types: 
16:44:53,998 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Static code analysis mode: DISABLE
16:44:54,545 INFO  akka.event.slf4j.Slf4jLogger                                  - Slf4jLogger started
16:44:54,560 DEBUG akka.event.EventStream                                        - logger log1-Slf4jLogger started
....
16:44:57,103 DEBUG org.apache.flink.api.java.typeutils.TypeExtractor             - class org.joda.time.LocalDateTime does not contain a getter for field iLocalMillis
16:44:57,103 DEBUG org.apache.flink.api.java.typeutils.TypeExtractor             - class org.joda.time.LocalDateTime does not contain a setter for field iLocalMillis
16:44:57,103 INFO  org.apache.flink.api.java.typeutils.TypeExtractor                 - class org.joda.time.LocalDateTime is not a valid POJO type
16:44:57,275 DEBUG org.apache.flink.api.scala.ClosureCleaner$                        - accessedFields: Map()
16:44:57,369 INFO  org.apache.flink.api.java.ExecutionEnvironment                - The job has 2 registered types and 0 default Kryo serializers
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo types: 
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo with Serializers types: 
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo with Serializer Classes types: Entry{k=class org.joda.time.DateTime, v=class de.javakaffee.kryoserializers.jodatime.JodaDateTimeSerializer},Entry{k=class org.joda.time.Interval, v=class de.javakaffee.kryoserializers.jodatime.JodaIntervalSerializer}
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo default Serializers: 
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered Kryo default Serializers Classes 
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Registered POJO types: 
16:44:57,369 DEBUG org.apache.flink.api.java.ExecutionEnvironment                - Static code analysis mode: DISABLE

尽管如此，我还是目睹了以下情况

Exception in thread "main" java.lang.NullPointerException
    at org.joda.time.LocalDateTime.isSupported(LocalDateTime.java:625)
    at org.joda.time.format.DateTimeFormatterBuilder$PaddedNumber.printTo(DateTimeFormatterBuilder.java:1435)
    at org.joda.time.format.DateTimeFormatterBuilder$Composite.printTo(DateTimeFormatterBuilder.java:2474)
    at org.joda.time.format.DateTimeFormatter.printTo(DateTimeFormatter.java:655)
    at org.joda.time.format.DateTimeFormatter.print(DateTimeFormatter.java:709)
    at org.joda.time.LocalDateTime.toString(LocalDateTime.java:2087)
    at java.lang.String.valueOf(Unknown Source)
    at scala.runtime.StringAdd$.$plus$extension(StringAdd.scala:13)
    at myflink.click.toString(Ingestor.scala:20)
    ...