NullPointerException when using rowtime with table api - apache-flink

Question

I have following simple code against flink 1.12.0, when I run it, exception throws, could someone help take a look? Thanks!
package org.example.model
import java.sql.Timestamp
case class Person2(name:String, birthday: Timestamp)
And
package org.example.sql2
import java.sql.Timestamp
import java.util.Date
import org.apache.flink.streaming.api.TimeCharacteristic
import org.apache.flink.streaming.api.functions.timestamps.BoundedOutOfOrdernessTimestampExtractor
import org.apache.flink.streaming.api.scala._
import org.apache.flink.streaming.api.windowing.time.Time
import org.apache.flink.table.api.bridge.scala._
import org.apache.flink.table.api.{AnyWithOperations, FieldExpression}
import org.apache.flink.types.Row
import org.example.model.Person2
object Sql014_EventTimeTest2 {
def main(args: Array[String]): Unit = {
val env = StreamExecutionEnvironment.getExecutionEnvironment
env.setParallelism(1)
env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime)
val ds: DataStream[Person2] = env.fromElements(Person2("Tom", new Timestamp(new Date().getTime)), Person2("Jack", new Timestamp(new Date().getTime)))
ds.assignTimestampsAndWatermarks(new BoundedOutOfOrdernessTimestampExtractor[Person2](Time.seconds(10)) {
override def extractTimestamp(t: Person2): Long = t.birthday.getTime
})
val tenv = StreamTableEnvironment.create(env)
val table = tenv.fromDataStream(ds, $"name", $"birthday", $"rt".rowtime())
table.toAppendStream[Row].print()
env.execute()
}
}
When I run the application, following exception occurs:
Exception in thread "main" org.apache.flink.runtime.client.JobExecutionException: Job execution failed.
at org.apache.flink.runtime.jobmaster.JobResult.toJobExecutionResult(JobResult.java:147)
at org.apache.flink.runtime.minicluster.MiniClusterJobClient.lambda$getJobExecutionResult$2(MiniClusterJobClient.java:119)
at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:602)
at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:577)
at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
at org.apache.flink.runtime.rpc.akka.AkkaInvocationHandler.lambda$invokeRpc$0(AkkaInvocationHandler.java:229)
at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
at org.apache.flink.runtime.concurrent.FutureUtils$1.onComplete(FutureUtils.java:996)
at akka.dispatch.OnComplete.internal(Future.scala:264)
at akka.dispatch.OnComplete.internal(Future.scala:261)
at akka.dispatch.japi$CallbackBridge.apply(Future.scala:191)
at akka.dispatch.japi$CallbackBridge.apply(Future.scala:188)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:36)
at org.apache.flink.runtime.concurrent.Executors$DirectExecutionContext.execute(Executors.java:74)
at scala.concurrent.impl.CallbackRunnable.executeWithValue(Promise.scala:44)
at scala.concurrent.impl.Promise$DefaultPromise.tryComplete(Promise.scala:252)
at akka.pattern.PromiseActorRef.$bang(AskSupport.scala:572)
at akka.pattern.PipeToSupport$PipeableFuture$$anonfun$pipeTo$1.applyOrElse(PipeToSupport.scala:22)
at akka.pattern.PipeToSupport$PipeableFuture$$anonfun$pipeTo$1.applyOrElse(PipeToSupport.scala:21)
at scala.concurrent.Future$$anonfun$andThen$1.apply(Future.scala:436)
at scala.concurrent.Future$$anonfun$andThen$1.apply(Future.scala:435)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:36)
at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:55)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply$mcV$sp(BatchingExecutor.scala:91)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:72)
at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:90)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:44)
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: org.apache.flink.runtime.JobException: Recovery is suppressed by NoRestartBackoffTimeStrategy
at org.apache.flink.runtime.executiongraph.failover.flip1.ExecutionFailureHandler.handleFailure(ExecutionFailureHandler.java:116)
at org.apache.flink.runtime.executiongraph.failover.flip1.ExecutionFailureHandler.getFailureHandlingResult(ExecutionFailureHandler.java:78)
at org.apache.flink.runtime.scheduler.DefaultScheduler.handleTaskFailure(DefaultScheduler.java:224)
at org.apache.flink.runtime.scheduler.DefaultScheduler.maybeHandleTaskFailure(DefaultScheduler.java:217)
at org.apache.flink.runtime.scheduler.DefaultScheduler.updateTaskExecutionStateInternal(DefaultScheduler.java:208)
at org.apache.flink.runtime.scheduler.SchedulerBase.updateTaskExecutionState(SchedulerBase.java:610)
at org.apache.flink.runtime.scheduler.SchedulerNG.updateTaskExecutionState(SchedulerNG.java:89)
at org.apache.flink.runtime.jobmaster.JobMaster.updateTaskExecutionState(JobMaster.java:419)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcInvocation(AkkaRpcActor.java:286)
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage(AkkaRpcActor.java:201)
at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor.handleRpcMessage(FencedAkkaRpcActor.java:74)
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage(AkkaRpcActor.java:154)
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26)
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21)
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123)
at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21)
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:170)
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171)
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171)
at akka.actor.Actor$class.aroundReceive(Actor.scala:517)
at akka.actor.AbstractActor.aroundReceive(AbstractActor.scala:225)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:592)
at akka.actor.ActorCell.invoke(ActorCell.scala:561)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258)
at akka.dispatch.Mailbox.run(Mailbox.scala:225)
at akka.dispatch.Mailbox.exec(Mailbox.scala:235)
... 4 more
Caused by: java.lang.NullPointerException
at SourceConversion$4.processElement(Unknown Source)
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.pushToOperator(CopyingChainingOutput.java:71)
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:46)
at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:26)
at org.apache.flink.streaming.runtime.tasks.BroadcastingOutputCollector.collect(BroadcastingOutputCollector.java:76)
at org.apache.flink.streaming.runtime.tasks.BroadcastingOutputCollector.collect(BroadcastingOutputCollector.java:32)
at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:52)
at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:30)
at org.apache.flink.streaming.api.operators.StreamSourceContexts$ManualWatermarkContext.processAndCollect(StreamSourceContexts.java:305)
at org.apache.flink.streaming.api.operators.StreamSourceContexts$WatermarkContext.collect(StreamSourceContexts.java:394)
at org.apache.flink.streaming.api.functions.source.FromElementsFunction.run(FromElementsFunction.java:164)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:100)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:63)
at org.apache.flink.streaming.runtime.tasks.SourceStreamTask$LegacySourceFunctionThread.run(SourceStreamTask.java:215)

Answer 1

The problem is that while you are calling assignTimestampsAndWatermarks on ds, you aren't doing anything with the result of this call. If you rework the code like this, it should work:
val streamWithTSandWM = ds.assignTimestampsAndWatermarks(new BoundedOutOfOrdernessTimestampExtractor[Person2](Time.seconds(10)) {
override def extractTimestamp(t: Person2): Long = t.birthday.getTime
})
val tenv = StreamTableEnvironment.create(env)
val table = tenv.fromDataStream(streamWithTSandWM, $"name", $"birthday", $"rt".rowtime())
Calling assignTimestampsAndWatermarks on a stream doesn't modify that stream, but instead returns a new stream that has timestamps and watermarks.