[MAHOUT-1215] NullPointerException in ItemSimilarityJob

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.7
• Fix Version/s: 0.7
• Labels: CF,recommendation,als NullPointerException,

Environment

hadoop etc

• Assignee: Sean R. Owen
• Reporter: LEE YOONJAE
• Created: 16/May/13 08:06
• Updated: 31/Jan/24 22:11
• Resolved: 16/May/13 08:31

Description

<--command-->
hadoop --config /engn001/sbp/scm/role/namenode/conf jar
/home/hdfs/mahout_test/mahout-core-0.7-job.jar \org.apache.mahout.cf.taste.hadoop.similarity.item.ItemSimilarityJob
--input /user/hdfs/mahout_test/input/mahout_input_final3_0.csv
--output /user/hdfs/mahout_test/output/final3/ItemSimilarity

<--error message-->
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.<init>(String.java:147)
at org.apache.commons.cli2.commandline.Parser.parse(Parser.java:66)
at org.apache.mahout.common.AbstractJob.parseArguments(AbstractJob.java:347)
at org.apache.mahout.common.AbstractJob.parseArguments(AbstractJob.java:317)
at org.apache.mahout.math.hadoop.similarity.cooccurrence.RowSimilarityJob.run(RowSimilarityJob.java:91)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.mahout.cf.taste.hadoop.similarity.item.ItemSimilarityJob.run(ItemSimilarityJob.java:145)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at org.apache.mahout.cf.taste.hadoop.similarity.item.ItemSimilarityJob.main(ItemSimilarityJob.java:91)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.RunJar.main(RunJar.java:156)

when I first did, it was successful, but in second time,
Exception in thread "main" java.lang.NullPointerException error occured
so I removed that temp directory,
and then in third time, NullPointerException occured.

Why is this error ocurred? and How can I fix it??