获取java.lang.NullPointerException hadoop map reduce程序
从db中提取数据并加载到另一个表时,我遇到以下错误:获取java.lang.NullPointerException hadoop map reduce程序,java,hadoop,Java,Hadoop,从db中提取数据并加载到另一个表时,我遇到以下错误: 15/07/01 04:23:15 INFO mapreduce.Job: Task Id : attempt_1434100146148_0014_m_000000_0, Status : FAILED Error: java.lang.NullPointerException at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.initialize(MapTask
15/07/01 04:23:15 INFO mapreduce.Job: Task Id : attempt_1434100146148_0014_m_000000_0, Status : FAILED
Error: java.lang.NullPointerException
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.initialize(MapTask.java:525)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:763)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:167)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1557)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
谢谢苏巴
上述问题已得到解决。我的输入sql查询中的列名有错误。我的查询为
select * from allTypes where **key** = ?;(correct)
select * from allTypes where **id** = ?;(wrong ...no column as id)
你能展示一些相关的代码吗?这绝对是一个NullPointerException。除此之外,没有您正在运行的代码,我们无法了解更多信息