Exception follows. java.lang.NullPointerException

[wenchangming211]

[ERROR - org.apache.flume.lifecycle.LifecycleSupervisor$MonitorRunnable.run(LifecycleSupervisor.java:251)] Unable to start PollableSourceRunner: { source:org.keedio.flume.source.SQLSource{name:sourcecost,state:IDLE} counterGroup:{ name:null counters:{} } } - Exception follows.
java.lang.NullPointerException
at org.keedio.flume.source.SQLSource.start(SQLSource.java:127)
at org.apache.flume.source.PollableSourceRunner.start(PollableSourceRunner.java:71)
at org.apache.flume.lifecycle.LifecycleSupervisor$MonitorRunnable.run(LifecycleSupervisor.java:249)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)