我已经安装了https://github.com/big-data-europe/docker-hadoop-spark-workbench
然后用docker-compose启动它.我导航到了the various urls mentioned in the git readme,所有人似乎都出现了.
然后我开始了一个本地的apache zeppelin：
./bin/zeppelin.sh start
在zeppelin解释器设置中,我已导航到spark解释器并更新master以指向安装了docker的本地群集
master：从local [*]更新到spark：// localhost：8080
然后我在笔记本中运行以下代码：
import org.apache.hadoop.fs.{FileSystem,Path}
FileSystem.get( sc.hadoopConfiguration ).listStatus( new Path("hdfs:///")).foreach( x => println(x.getPath ))
我在zeppelin日志中遇到此异常：
INFO [2017-12-15 18:06:35,704] ({pool-2-thread-2} Paragraph.java[jobRun]:362) - run paragraph 20171212-200101_1553252595 using null org.apache.zeppelin.interpreter.LazyOpenInterpreter@32d09a20
WARN [2017-12-15 18:07:37,717] ({pool-2-thread-2} NotebookServer.java[afterStatusChange]:2064) - Job 20171212-200101_1553252595 is finished,status: ERROR,exception: null,result: %text java.lang.NullPointerException
at org.apache.zeppelin.spark.Utils.invokeMethod(Utils.java:38)
at org.apache.zeppelin.spark.Utils.invokeMethod(Utils.java:33)
at org.apache.zeppelin.spark.SparkInterpreter.createSparkContext_2(SparkInterpreter.java:398)
at org.apache.zeppelin.spark.SparkInterpreter.createSparkContext(SparkInterpreter.java:387)
at org.apache.zeppelin.spark.SparkInterpreter.getSparkContext(SparkInterpreter.java:146)
at org.apache.zeppelin.spark.SparkInterpreter.open(SparkInterpreter.java:843)
at org.apache.zeppelin.interpreter.LazyOpenInterpreter.open(LazyOpenInterpreter.java:70)
at org.apache.zeppelin.interpreter.remote.RemoteInterpreterServer$InterpretJob.jobRun(RemoteInterpreterServer.java:491)
at org.apache.zeppelin.scheduler.Job.run(Job.java:175)
at org.apache.zeppelin.scheduler.FIFOScheduler$1.run(FIFOScheduler.java:139)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
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:748)
如何从zeppelin和java / spark代码访问hdfs？
最佳答案
异常的原因是在Zeppelin中由于某种原因,sparkSession对象为null.
private SparkContext createSparkContext_2() {
return (SparkContext) Utils.invokeMethod(sparkSession,"sparkContext");
}
可能是与配置相关的问题.请交叉验证设置/配置和火花群设置.确保火花正常工作.
参考：https://zeppelin.apache.org/docs/latest/interpreter/spark.html
希望这可以帮助.
