Hi Rupert, Thank for the prompt reply.
When I checked the incoming_links.txt the final lines were as follows 1 m.0___xpc 1 m.0___xk_ 1 m.0___ttg 1 m.0___t6s 1 m.0___t6h 1 m.0___t5v 1 m.0___t5c 1 m.0___rw7 1 m.0___qhn 1 m.0___p3v 1 m.0___nm5 1 m.0___n4s 1 m.0___n 1 m.0___jk_ 1 m.0___hv4 1 m.0___c6k 1 m.0___b4g 1 m.0___8 1 m.0___7yv 1 m.0___2fw 1 m.0____ So the entities are not preceded with a name space. Therefore when calling String prefix = NamespaceMappingUtils.getPrefix(entity); (LineBasedEntityIterator.parseEntityFormLine(String line) - 425), prefix is assigned with a empty String. Is it correct to defined an empty name space mapping as follows in the namespaceprefix.mapping? fb http://rdf.freebase.com/ns/ ns http://rdf.freebase.com/ns/ key http://rdf.freebase.com/key/ http://rdf.freebase.com/ns/ Thanks Regards Amindri On 9 February 2015 at 17:52, Rupert Westenthaler < rupert.westentha...@gmail.com> wrote: > Hi Amindri > > Based on the code the NPE could originate from a namespace prefix > unknown to the namespace prefix service. > > Can you please check the data of the "incoming_links.txt" file against > mappings define in the "indexing/config/namespaceprefix.mappings" > file. My guess is that the "incoming_links.txt" uses a prefix that is > not define in the mappings file. > > It is recommended to explicitly define namespace prefix mappings for > all namespaces used by the indexing process (config data and rdf > data). For missing mappings http://prefix.cc/ is used as a fallback. > > best > Rupert > > > On Mon, Feb 9, 2015 at 7:33 AM, Amindri Udugala > <amindriudug...@gmail.com> wrote: > > Hi All, > > > > I need to create an index from a Freebase data dump. So I followed the > > instructions in the README file in entityhub\indexing\freebase. > > > > First I executed java -jar > > org.apache.stanbol.entityhub.indexing.freebase-1.0.0-SNAPSHOT.jar init, > to > > generate the folder structure. The folder structure was successfully > > generated except for the following warnings > > > > 16:16:20,530 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'nsogi' valid , namespace ' > http://prefix.cc/nsogi:' > > invalid -> mapping ignored! > > 16:16:21,279 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'category' valid , namespace ' > > http://dbpedia.org/resource/Category:' invalid -> mapping ignored! > > 16:16:21,435 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'chebi' valid , namespace ' > > http://bio2rdf.org/chebi:' invalid -> mapping ignored! > > 16:16:21,435 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'hgnc' valid , namespace ' > http://bio2rdf.org/hgnc:' > > invalid -> mapping ignored! > > 16:16:21,450 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'dbptmpl' valid , namespace ' > > http://dbpedia.org/resource/Template:' invalid -> mapping ignored! > > 16:16:21,638 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'pubmed' valid , namespace ' > > http://bio2rdf.org/pubmed_vocabulary:' invalid -> mapping ignored! > > 16:16:21,638 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'dbc' valid , namespace ' > > http://dbpedia.org/resource/Category:' invalid -> mapping ignored! > > 16:16:21,638 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'dbt' valid , namespace ' > > http://dbpedia.org/resource/Template:' invalid -> mapping ignored! > > 16:16:21,638 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'dbrc' valid , namespace ' > > http://dbpedia.org/resource/Category:' invalid -> mapping ignored! > > 16:16:21,809 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'call' valid , namespace ' > > http://webofcode.org/wfn/call:' invalid -> mapping ignored! > > 16:16:21,809 [main] WARN impl.NamespacePrefixProviderImpl - Invalid > > Namespace Mapping: prefix 'affymetrix' valid , namespace ' > > http://bio2rdf.org/affymetrix_vocabulary:' invalid -> mapping ignored! > > > > Then I copied the Freebase dump (freebase-rdf-latest.gz) to the > > indexing/resources/rdfdata folder > > and the incoming_links.txt file, generated by fbrankings-uri.sh to > > indexing/resources folder and executed the indexing process. (I used all > > the default config files) > > > > While executing the index process I noticed the following log. > > > > > > 16:38:40,806 [main] INFO core.IndexerFactory - - EntityDataIterable: > null > > 16:38:40,806 [main] INFO core.IndexerFactory - - EntityIterator: > > > org.apache.stanbol.entityhub.indexing.core.source.LineBasedEntityIterator@1880249c > > 16:38:40,806 [main] INFO core.IndexerFactory - - EntityDataProvider: > > > org.apache.stanbol.entityhub.indexing.source.jenatdb.RdfIndexingSource@4e38a55 > > 16:38:40,806 [main] INFO core.IndexerFactory - - EntityScoreProvider: > null > > > > Finally it threw a null pointer exception as follows > > > > 16:38:40,837 [Thread-3] INFO source.ResourceLoader - ... 1 files > imported > > in 0 seconds > > 16:38:40,837 [Thread-3] INFO source.ResourceLoader - Loding 0 File ... > > 16:38:40,837 [Thread-3] INFO source.ResourceLoader - ... 0 files > imported > > in 0 seconds > > 16:38:42,912 [Thread-0] INFO solryard.SolrYardIndexingDestination - > ... > > create SolrYard > > 16:38:42,959 [main] INFO impl.IndexerImpl - ... delete existing > > IndexedEntityId file > > > C:\cygwin64\home\User\code\stanbol_indexing\indexing\destination\indexed-entities-ids.zip > > 16:38:42,974 [main] INFO impl.IndexerImpl - Initialisation completed > > 16:38:42,974 [main] INFO impl.IndexerImpl - ... initialisation > completed > > 16:38:42,974 [main] INFO impl.IndexerImpl - start indexing ... > > 16:38:42,974 [main] INFO impl.IndexerImpl - Indexing started ... > > Exception in thread "Indexing: Entity Source Reader Deamon" > > java.lang.NullPointerException > > at java.lang.StringBuilder.<init>(Unknown Source) > > at > > > org.apache.stanbol.entityhub.indexing.core.source.LineBasedEntityIterator.parseEntityFormLine(LineBasedEntityIterator.java:435) > > at > > > org.apache.stanbol.entityhub.indexing.core.source.LineBasedEntityIterator.getNext(LineBasedEntityIterator.java:379) > > at > > > org.apache.stanbol.entityhub.indexing.core.source.LineBasedEntityIterator.hasNext(LineBasedEntityIterator.java:356) > > at > > > org.apache.stanbol.entityhub.indexing.core.impl.EntityIdBasedIndexingDaemon.run(EntityIdBasedIndexingDaemon.java:55) > > at java.lang.Thread.run(Unknown Source) > > > > I'm not sure if this happens because I haven't configured an important > > property in a configuration file. I'm pretty new to Stanbol and any help > > would be much appreciated. > > > > Thanks in advance. > > -- > > Regards > > Amindri Udugala > > > > -- > | Rupert Westenthaler rupert.westentha...@gmail.com > | Bodenlehenstraße 11 ++43-699-11108907 > | A-5500 Bischofshofen > | REDLINK.CO > .......................................................................... > | http://redlink.co/ > -- Regards Amindri Udugala