由于spark算子用到的class没有实现序列化，报错如下所示

15/11/23 14:43:47 ERROR Executor: Exception in task 0.0 in stage 4.0 (TID 4)

java.io.NotSerializableException: EntityMention

Serialization stack:

- object not serializable (class: EntityMention, value: EntityMention@5cdadff6)

at org.apache.spark.serializer.SerializationDebugger$.improveException(SerializationDebugger.scala:40)

at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:47)

at org.apache.spark.serializer.SerializationStream.writeValue(Serializer.scala:147)

at org.apache.spark.storage.DiskBlockObjectWriter.write(DiskBlockObjectWriter.scala:181)

at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.insertAll(BypassMergeSortShuffleWriter.java:121)

at org.apache.spark.shuffle.sort.SortShuffleWriter.write(SortShuffleWriter.scala:73)

at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:73)

at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41)

at org.apache.spark.scheduler.Task.run(Task.scala:88)

at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

at java.lang.Thread.run(Thread.java:744)

15/11/23 14:43:47 ERROR TaskSetManager: Task 0.0 in stage 4.0 (TID 4) had a not serializable result: EntityMention

Serialization stack:

- object not serializable (class: EntityMention, value: EntityMention@5cdadff6); not retrying

15/11/23 14:43:47 INFO TaskSchedulerImpl: Removed TaskSet 4.0, whose tasks have all completed, from pool

15/11/23 14:43:47 INFO TaskSchedulerImpl: Cancelling stage 4

15/11/23 14:43:47 INFO DAGScheduler: ShuffleMapStage 4 (groupBy at Relation_Detector.scala:78) failed in 0.081 s

15/11/23 14:43:47 INFO DAGScheduler: Job 4 failed: collect at Relation_Detector.scala:79, took 0.097801 s

Exception in thread "main" org.apache.spark.SparkException: Job aborted due to stage failure: Task 0.0 in stage 4.0 (TID 4) had a not serializable result: EntityMention

Serialization stack:

- object not serializable (class: EntityMention, value: EntityMention@5cdadff6)

at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1283)

at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1271)

at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1270)

at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)

at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)

at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1270)

at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:697)

at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:697)

at scala.Option.foreach(Option.scala:236)

at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:697)

at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1496)

at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1458)

at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1447)

at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)

at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:567)

at org.apache.spark.SparkContext.runJob(SparkContext.scala:1822)

at org.apache.spark.SparkContext.runJob(SparkContext.scala:1835)

at org.apache.spark.SparkContext.runJob(SparkContext.scala:1848)

at org.apache.spark.SparkContext.runJob(SparkContext.scala:1919)

at org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:905)

at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:147)

at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:108)

at org.apache.spark.rdd.RDD.withScope(RDD.scala:306)

at org.apache.spark.rdd.RDD.collect(RDD.scala:904)

at Relation_Detector$.main(Relation_Detector.scala:79)

at Relation_Detector.main(Relation_Detector.scala)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:606)

at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

15/11/23 14:43:47 INFO SparkContext: Invoking stop() from shutdown hook

解决方法：对类实现序列化Serializable

class EntityMention(val pentitymention_id:String,var pname:String,var pentitymention_type:String,

var pHbaseID:String,var ptopicID:String,var ppost_type:String,

var psenIndex:String,var psenOffset:String, var ppostTime:String,

var pinsertTime:String,var pentityID:String) extends Serializable {

var entitymention_id = pentitymention_id

var name = pname

var entitymention_type = pentitymention_type

var HbaseID = pHbaseID

var topicID= ptopicID

var post_type = ppost_type

var senIndex = psenOffset

var senOffset = psenOffset

var postTime = ppostTime

var insertTime = pinsertTime

var entityID = pentityID

}