在執行spark on hive 的時候在  sql.show()處報錯 ： Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/fs/CanUnbuffer

報錯詳情：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/fs/CanUnbuffer
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2591)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:89)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2625)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2607)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:368)
	at org.apache.hadoop.fs.Path.getFileSystem(Path.java:296)
	at org.apache.hadoop.mapred.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:256)
	at org.apache.hadoop.mapred.FileInputFormat.listStatus(FileInputFormat.java:228)
	at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:313)
	at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:194)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
	at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
	at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
	at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
	at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
	at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
	at scala.Option.getOrElse(Option.scala:121)
	at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
	at org.apache.spark.sql.execution.SparkPlan.executeTake(SparkPlan.scala:314)
	at org.apache.spark.sql.execution.CollectLimitExec.executeCollect(limit.scala:38)
	at org.apache.spark.sql.Dataset.org$apache$spark$sql$Dataset$$collectFromPlan(Dataset.scala:2853)
	at org.apache.spark.sql.Dataset$$anonfun$head$1.apply(Dataset.scala:2153)
	at org.apache.spark.sql.Dataset$$anonfun$head$1.apply(Dataset.scala:2153)
	at org.apache.spark.sql.Dataset$$anonfun$55.apply(Dataset.scala:2837)
	at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:65)
	at org.apache.spark.sql.Dataset.withAction(Dataset.scala:2836)
	at org.apache.spark.sql.Dataset.head(Dataset.scala:2153)
	at org.apache.spark.sql.Dataset.take(Dataset.scala:2366)
	at org.apache.spark.sql.Dataset.showString(Dataset.scala:245)
	at org.apache.spark.sql.Dataset.show(Dataset.scala:644)
	at org.apache.spark.sql.Dataset.show(Dataset.scala:603)
	at org.apache.spark.sql.Dataset.show(Dataset.scala:612)
	at com.sparksql.spark_on_hive.main(spark_on_hive.java:35)
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.fs.CanUnbuffer
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 62 more

　　說明：程式是在idea上本地執行。

　　問題：原因不明！！！！！！！！！！

　　解決：上網找了許多的錯誤原因，都說是hadoop的環境問題，但是我加過hadoop classpath後依然沒有用。

　　　　　最終解決是我刪除了pom.xml檔案中的hbase的依賴（程式執行中並沒有用到）然後莫名奇妙就好了。在把原來的hbase的依賴加上去還是報錯。

　　　　　因為前面我pom.xml檔案中的hbase的依賴在hadoop依賴之前，所以報錯，後來我把hbase的依賴放到了hadoop的依賴後面就可以。

　　猜想：可能是hbase依賴中有什麼東西把hadoop依賴中的什麼東西頂掉了。把hadoop放到hbase之前就解決了問題。