当我在eclipse maven环境中执行我的代码时，我收到此错误，因为我是java新手，不知道如何继续进行，请解决任何问题。
Exception in thread "main" cascading.flow.FlowException: unhandled exception
at cascading.flow.BaseFlow.complete(BaseFlow.java:954)
at com.bitwiseglobal.engine.integration.BHSRuntime.execute(BHSRuntime.java:170)
at com.bitwiseglobal.bhse.utilities.BHSExecution.execute(BHSExecution.java:50)
at com.bitwiseglobal.bhse.utilities.BHSExecution.main(BHSExecution.java:29)
Caused by: java.lang.NullPointerException
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1010)
at org.apache.hadoop.util.Shell.runCommand(Shell.java:482)
at org.apache.hadoop.util.Shell.run(Shell.java:455)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:808)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:791)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:656)
at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:444)
at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:293)
at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:133)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:437)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1296)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1293)
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:1628)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1293)
at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:562)
at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:557)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:557)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:548)
at cascading.flow.hadoop.planner.HadoopFlowStepJob.internalNonBlockingStart(HadoopFlowStepJob.java:100)
at cascading.flow.planner.FlowStepJob.blockOnJob(FlowStepJob.java:248)
at cascading.flow.planner.FlowStepJob.start(FlowStepJob.java:172)
at cascading.flow.planner.FlowStepJob.call(FlowStepJob.java:134)
at cascading.flow.planner.FlowStepJob.call(FlowStepJob.java:45)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
由于级联问题或由于java空指针异常导致此错误。如果需要任何细节，请告诉我。