Is that the complete stack trace? Threaded code like this usually has two or three levels of "Caused by" seconds. The last is the critical one.
On Fri, Sep 24, 2010 at 1:07 PM, Stanley Ipkiss <[email protected]>wrote: > > I did that change yesterday in my code, but forgot to post the update here. > The error that I get sometimes is - > > Caused by: java.lang.NullPointerException > at > > org.apache.mahout.cf.taste.impl.similarity.file.FileItemSimilarity.itemSimilarities(FileItemSimilarity.java:108) > at > > org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.doEstimatePreference(GenericItemBasedRecommender.java:195) > at > > org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.estimatePreference(GenericItemBasedRecommender.java:126) > at > > org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$EstimatedPrefRetriever.get(CachingRecommender.java:214) > at > > org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$EstimatedPrefRetriever.get(CachingRecommender.java:1) > at > > org.apache.mahout.cf.taste.impl.common.Cache.getAndCacheValue(Cache.java:127) > at org.apache.mahout.cf.taste.impl.common.Cache.get(Cache.java:96) > at > > org.apache.mahout.cf.taste.impl.recommender.CachingRecommender.estimatePreference(CachingRecommender.java:128) > > I am still looking into for what particular case, does the > FileItemSimilarity go crazy. > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Possible-multi-thread-issue-in-AbstractDifferenceRecommenderEvaluator-tp1571411p1576371.html > Sent from the Mahout User List mailing list archive at Nabble.com. >
