Run Spark Program in idea and find that datafram can perform df.show() but just df.count() will display the following exception information:

2022-03-25 17:56:13,691 ERROR executor.Executor: Exception in task 14.0 in stage 7.0 (TID 222)
java.lang.NullPointerException
	at $line33.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw.$anonfun$rdd01$1(<console>:26)
	at scala.collection.Iterator$$anon$10.next(Iterator.scala:461)
	at scala.collection.Iterator$$anon$11.nextCur(Iterator.scala:486)
	at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:492)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:460)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.agg_doAggregateWithKeys_0$(Unknown Source)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.processNext(Unknown Source)
	at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
	at org.apache.spark.sql.execution.WholeStageCodegenExec$$anon$1.hasNext(WholeStageCodegenExec.scala:759)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:460)
	at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:140)
	at org.apache.spark.shuffle.ShuffleWriteProcessor.write(ShuffleWriteProcessor.scala:59)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:52)
	at org.apache.spark.scheduler.Task.run(Task.scala:131)
	at org.apache.spark.executor.Executor$TaskRunner.$anonfun$run$3(Executor.scala:506)
	at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1462)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:509)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
2022-03-25 17:56:13,728 WARN scheduler.TaskSetManager: Lost task 14.0 in stage 7.0 (TID 222) (westgis-134 executor driver): java.lang.NullPointerException
	at $line33.$read$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw$$iw.$anonfun$rdd01$1(<console>:26)
	at scala.collection.Iterator$$anon$10.next(Iterator.scala:461)
	at scala.collection.Iterator$$anon$11.nextCur(Iterator.scala:486)
	at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:492)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:460)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.agg_doAggregateWithKeys_0$(Unknown Source)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.processNext(Unknown Source)
	at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
	at org.apache.spark.sql.execution.WholeStageCodegenExec$$anon$1.hasNext(WholeStageCodegenExec.scala:759)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:460)
	at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:140)
	at org.apache.spark.shuffle.ShuffleWriteProcessor.write(ShuffleWriteProcessor.scala:59)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:52)
	at org.apache.spark.scheduler.Task.run(Task.scala:131)
	at org.apache.spark.executor.Executor$TaskRunner.$anonfun$run$3(Executor.scala:506)
	at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1462)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:509)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

The reason for this error is that there is a null value in the dataframe attribute in the previous processing, using na.drop() is removed and the error is resolved.

df05=df05.select("direction","station_name","order_no","lat","lng").na.drop()