I'm glad you got your function working. Now that I look at it, it seems possible that you could use a built-in SPARQL function:
https://www.w3.org/TR/sparql11-query/#func-strlen Adam Soroka > On Dec 26, 2017, at 3:50 PM, Marc Agate <[email protected]> wrote: > > Hi, > > I finally got the whole test working properly > > To summarize: > > 1) Deploy the custom functions classes on fuseki server > 2) Modify the fuseki config : > > add [] ja:loadClass "io.bdrc.ldsearch.query.functions.MyFilter" > > where MyFilter implementation is : > > import org.apache.jena.sparql.expr.NodeValue; > import org.apache.jena.sparql.function.FunctionBase1; > > > public class MyFilter extends FunctionBase1 { > > public MyFilter() { super() ; } > > public NodeValue exec(NodeValue value1){ > > int d = value1.asString().length(); > return NodeValue.makeInteger(new Integer(d)); > } > } > > 3) add the following prefix to the context: > > PREFIX f: <java:io.bdrc.ldsearch.query.functions.> > > Note that "io.bdrc.ldsearch.query.functions is the package of MyFilter > class, not the class itself --> this means that you never call a class > method in sparql queries but only a class that implements > org.apache.jena.sparql.function.FunctionBaseX where X is the number of > argument of your filter function > > 4) Write (for instance) the query like this: > > SELECT DISTINCT ?l > WHERE { ?x skos:prefLabel ?l . > FILTER (f:MyFilter(?l) < 20) > } > > Thanks to Adam and Andy > > Marc > > Le mardi 26 décembre 2017 à 19:44 +0000, Andy Seaborne a écrit : >>> Exception in thread "main" HttpException: 404 at >>> org.apache.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java >>> :328 >>> ) >> >> 404 - HTTP not found - when trying to call Fuseki - i.e. the query >> service URL is wrong. A server is running at the address (host:port) >> but >> the path does not name an HTTP resource. >> >> Andy >> >> >> On 26/12/17 19:00, ajs6f wrote: >>> I don't understand how that config is getting parsed at all. It's >>> not valid Turtle. >>> >>>> ja:loadClass >>>> "io.bdrc.ldsearch.query.functions.CustomARQFunctions" . >>> >>> is not a triple at all. It should probably be: >>> >>> [] ja:loadClass >>> "io.bdrc.ldsearch.query.functions.CustomARQFunctions" . >>> >>> Riot gives "Expected IRI for predicate: got: >>> [STRING:io.bdrc.ldsearch.query.functions.CustomARQFunctions]" >>> >>> It's not clear to me how you could be successfully loading your >>> extension function with invalid config. >>> >>> Adam Soroka >>> >>> >>>> On Dec 26, 2017, at 1:42 PM, Marc Agate <[email protected]> >>>> wrote: >>>> >>>> Well... >>>> >>>> Here is the query >>>> >>>> PREFIX : <http://purl.bdrc.io/ontology/core/> >>>> PREFIX adm: <http://purl.bdrc.io/ontology/admin/> >>>> PREFIX bdr: <http://purl.bdrc.io/resource/> >>>> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> >>>> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> >>>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> >>>> PREFIX tbr: <http://purl.bdrc.io/ontology/toberemoved/> >>>> PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> >>>> PREFIX f: >>>> <java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.> >>>> >>>> SELECT DISTINCT ?l >>>> WHERE { >>>> ?x skos:prefLabel ?l . >>>> FILTER (f:myFilter(?l) < 100) >>>> } >>>> >>>> Note that whene I change FILTER (f:myFilter(?l) < 100) to FILTER >>>> (STRLEN(?l) < 100), I don't get the 404 exception... >>>> Therefore it's not a connection issue. I thing it's more like a >>>> unresolved URI or so. >>>> >>>> Now, since you'are asking for it, here is the full fuseki config: >>>> >>>> ################################################################ >>>> # Fuseki configuration for BDRC, configures two endpoints: >>>> # - /bdrc is read-only >>>> # - /bdrcrw is read-write >>>> # >>>> # This was painful to come up with but the web interface >>>> basically >>>> allows no option >>>> # and there is no subclass inference by default so such a >>>> configuration >>>> file is necessary. >>>> # >>>> # The main doc sources are: >>>> # - https://jena.apache.org/documentation/fuseki2/fuseki-configu >>>> ration >>>> .html >>>> # - https://jena.apache.org/documentation/assembler/assembler-ho >>>> wto.ht >>>> ml >>>> # - https://jena.apache.org/documentation/assembler/assembler.tt >>>> l >>>> # >>>> # See https://jena.apache.org/documentation/fuseki2/fuseki-layout >>>> .html >>>> for the destination of this file. >>>> >>>> @prefix fuseki: <http://jena.apache.org/fuseki#> . >>>> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . >>>> @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . >>>> @prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> . >>>> # @prefix tdb2: <http://jena.apache.org/2016/tdb#> . >>>> @prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> . >>>> @prefix : <http://base/#> . >>>> @prefix text: <http://jena.apache.org/text#> . >>>> @prefix skos: <http://www.w3.org/2004/02/skos/core#> . >>>> @prefix adm: <http://purl.bdrc.io/ontology/admin/> . >>>> @prefix bdd: <http://purl.bdrc.io/data/> . >>>> @prefix bdo: <http://purl.bdrc.io/ontology/core/> . >>>> @prefix bdr: <http://purl.bdrc.io/resource/> . >>>> @prefix f: >>>> <java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.> >>>> . >>>> >>>> ja:loadClass >>>> "io.bdrc.ldsearch.query.functions.CustomARQFunctions" . >>>> # [] ja:loadClass "org.seaborne.tdb2.TDB2" . >>>> # tdb2:DatasetTDB2 rdfs:subClassOf ja:RDFDataset . >>>> # tdb2:GraphTDB2 rdfs:subClassOf ja:Model . >>>> >>>> [] rdf:type fuseki:Server ; >>>> fuseki:services ( >>>> :bdrcrw >>>> # :bdrcro >>>> ) . >>>> >>>> :bdrcrw rdf:type fuseki:Service ; >>>> fuseki:name "bdrcrw" ; # name of >>>> the >>>> dataset in the url >>>> fuseki:serviceQuery "query" ; # SPARQL >>>> query >>>> service >>>> fuseki:serviceUpdate "update" ; # SPARQL >>>> update >>>> service >>>> fuseki:serviceUpload "upload" ; # Non-SPARQL >>>> upload >>>> service >>>> fuseki:serviceReadWriteGraphStore "data" ; # SPARQL >>>> Graph store >>>> protocol (read and write) >>>> fuseki:dataset :bdrc_text_dataset ; >>>> . >>>> >>>> # :bdrcro rdf:type fuseki:Service ; >>>> # fuseki:name "bdrc" ; >>>> # fuseki:serviceQuery "query" ; >>>> # fuseki:serviceReadGraphStore "data" ; >>>> # fuseki:dataset :bdrc_text_dataset >>>> ; >>>> # . >>>> >>>> # using TDB >>>> :dataset_bdrc rdf:type tdb:DatasetTDB ; >>>> tdb:location "/etc/fuseki/databases/bdrc" ; >>>> tdb:unionDefaultGraph true ; >>>> . >>>> >>>> # # try using TDB2 >>>> # :dataset_bdrc rdf:type tdb2:DatasetTDB2 ; >>>> # tdb2:location "/etc/fuseki/databases/bdrc" ; >>>> # tdb2:unionDefaultGraph true ; >>>> # . >>>> >>>> :bdrc_text_dataset rdf:type text:TextDataset ; >>>> text:dataset :dataset_bdrc ; >>>> text:index :bdrc_lucene_index ; >>>> . >>>> >>>> # Text index description >>>> :bdrc_lucene_index a text:TextIndexLucene ; >>>> text:directory <file:/etc/fuseki/lucene-bdrc> ; >>>> text:storeValues true ; >>>> text:multilingualSupport true ; >>>> text:entityMap :bdrc_entmap ; >>>> text:defineAnalyzers ( >>>> [ text:addLang "bo" ; >>>> text:analyzer [ >>>> a text:GenericAnalyzer ; >>>> text:class "io.bdrc.lucene.bo.TibetanAnalyzer" ; >>>> text:params ( >>>> [ text:paramName "segmentInWords" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue false ] >>>> [ text:paramName "lemmatize" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue true ] >>>> [ text:paramName "filterChars" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue false ] >>>> [ text:paramName "fromEwts" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue false ] >>>> ) >>>> ] ; >>>> ] >>>> [ text:addLang "bo-x-ewts" ; >>>> text:analyzer [ >>>> a text:GenericAnalyzer ; >>>> text:class "io.bdrc.lucene.bo.TibetanAnalyzer" ; >>>> text:params ( >>>> [ text:paramName "segmentInWords" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue false ] >>>> [ text:paramName "lemmatize" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue true ] >>>> [ text:paramName "filterChars" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue false ] >>>> [ text:paramName "fromEwts" ; >>>> text:paramType text:TypeBoolean ; >>>> text:paramValue true ] >>>> ) >>>> ] ; >>>> ] >>>> ) ; >>>> . >>>> >>>> # Index mappings >>>> :bdrc_entmap a text:EntityMap ; >>>> text:entityField "uri" ; >>>> text:uidField "uid" ; >>>> text:defaultField "label" ; >>>> text:langField "lang" ; >>>> text:graphField "graph" ; ## enable graph-specific >>>> indexing >>>> text:map ( >>>> [ text:field "label" ; >>>> text:predicate skos:prefLabel ] >>>> [ text:field "altLabel" ; >>>> text:predicate skos:altLabel ; ] >>>> [ text:field "rdfsLabel" ; >>>> text:predicate rdfs:label ; ] >>>> [ text:field "chunkContents" ; >>>> text:predicate bdo:chunkContents ; ] >>>> [ text:field "eTextTitle" ; >>>> text:predicate bdo:eTextTitle ; ] >>>> [ text:field "logMessage" ; >>>> text:predicate adm:logMessage ; ] >>>> [ text:field "noteText" ; >>>> text:predicate bdo:noteText ; ] >>>> [ text:field "workAuthorshipStatement" ; >>>> text:predicate bdo:workAuthorshipStatement ; ] >>>> [ text:field "workColophon" ; >>>> text:predicate bdo:workColophon ; ] >>>> [ text:field "workEditionStatement" ; >>>> text:predicate bdo:workEditionStatement ; ] >>>> [ text:field "workPublisherLocation" ; >>>> text:predicate bdo:workPublisherLocation ; ] >>>> [ text:field "workPublisherName" ; >>>> text:predicate bdo:workPublisherName ; ] >>>> [ text:field "workSeriesName" ; >>>> text:predicate bdo:workSeriesName ; ] >>>> ) ; >>>> . >>>> ################################################################# >>>> ## >>>> >>>> It would be wonderful to have the java:URI scheme thing working >>>> (all >>>> custom functions in a single class and method calls done directly >>>> in >>>> the sparql query : sounds like a dream !) >>>> >>>> Marc >>>> >>>> Le mardi 26 décembre 2017 à 13:22 -0500, ajs6f a écrit : >>>>> That exception doesn't appear to have anything to do with >>>>> extension >>>>> functions. It indicates a problem between client and server. >>>>> >>>>> Please show at _least_ your actual query execution code, your >>>>> complete Fuseki config, and a complete stacktrace. >>>>> >>>>> >>>>> ajs6f >>>>> >>>>>> On Dec 26, 2017, at 1:17 PM, Marc Agate <[email protected] >>>>>>> >>>>>> wrote: >>>>>> >>>>>> I forgot to mention that according to >>>>>> https://jena.apache.org/documentation/query/java-uri.html >>>>>> I tried for testing purpose to set a PREFIX f: >>>>>> <java:io.bdrc.ldsearch.query.functions.CustomARQFunctions.>an >>>>>> d >>>>>> added >>>>>> the following to fuseki config : >>>>>> ja:loadClass >>>>>> "io.bdrc.ldsearch.query.functions.CustomARQFunctions" >>>>>> . >>>>>> where CustomARQFunctions is : >>>>>> public class CustomARQFunctions { public >>>>>> static >>>>>> NodeValue myFilter(NodeValue value1){ >>>>>> int i >>>>>> = >>>>>> value1.asString().length(); return >>>>>> NodeValue.makeInteger(i); } >>>>>> } >>>>>> since according to >>>>>> https://jena.apache.org/documentation/query/writing_functions >>>>>> .html >>>>>> using the java:URI scheme "dynamically loads the code, which >>>>>> must >>>>>> be on >>>>>> the Java classpath. With this scheme, the function URI gives >>>>>> the >>>>>> class >>>>>> name. There is automatic registration of a wrapper into the >>>>>> function >>>>>> registry. This way, no explicit registration step is needed >>>>>> by the >>>>>> application and queries issues with the command line tools >>>>>> can load >>>>>> custom functions." >>>>>> but no luck: I keep getting the following exception: >>>>>> Exception in thread "main" HttpException: 404 at >>>>>> org.apache.jena.sparql.engine.http.HttpQuery.execGet(HttpQuer >>>>>> y.java >>>>>> :328 >>>>>> ) at >>>>>> org.apache.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.j >>>>>> ava:28 >>>>>> 8) >>>>>> at >>>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execResult >>>>>> SetInn >>>>>> er(Q >>>>>> ueryEngineHTTP.java:348) at >>>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execSelect >>>>>> (Query >>>>>> Engi >>>>>> neHTTP.java:340) >>>>>> I am stuck ! >>>>>> Marc >>>>>> Le mardi 26 décembre 2017 à 18:56 +0100, Marc Agate a écrit : >>>>>>> Hi, >>>>>>> Adam's gave me the right direction. >>>>>>> I managed to load my function class in fuseki config using >>>>>>> ja:loadClass >>>>>>> but now remains the following issue (the function is not >>>>>>> registered)seefuseki logs : >>>>>>> [2017-12-26 16:10:13] exec WARN URI <http://purl.bdr >>>>>>> c.io/f >>>>>>> unct >>>>>>> ions#MyFilterFunction> has no registered function factory >>>>>>> How can I register this function now that I have the code >>>>>>> available >>>>>>> onthe endpoint side ? >>>>>>> Thanks for helping >>>>>>> Marc. >>>>>>> >>>>>>> Le mardi 26 décembre 2017 à 17:43 +0000, Andy Seaborne a >>>>>>> écrit : >>>>>>>> As well s Adam's point (and all the libraries your >>>>>>>> function >>>>>>>> needs, transitively) >>>>>>>> What is in the Fuseki log file?How was the data loaded >>>>>>>> into >>>>>>>> Fuseki? >>>>>>>> >> I printed out the >> FunctionRegistry >>>>>>>> And >>>>>>>> On 26/12/17 14:51, ajs6f wrote: >>>>>>>>> I'm not as familiar with the extension points of ARQ as >>>>>>>>> I >>>>>>>>> wouldlike to be, but as I understand what you are >>>>>>>>> doing, you >>>>>>>>> areregistering a new function with your _local_ >>>>>>>>> registry, >>>>>>>>> then >>>>>>>>> firinga query at a _remote_ endpoint (which has a >>>>>>>>> completely >>>>>>>>> independentregistry in a different JVM in a different >>>>>>>>> process, >>>>>>>>> potentially ina different _system_). >>>>>>>>> The query is getting interpreted and executed by that >>>>>>>>> remoteservice, not locally. So you need to register the >>>>>>>>> function >>>>>>>>> _there_. >>>>>>>>> Take a look at this thread: >>>>>>>>> https://lists.apache.org/thread.html/1cda23332af4264883 >>>>>>>>> e88697 >>>>>>>>> d994 >>>>>>>>> 605770edcde2f93ddea51240e4b8@%3Cusers.jena.apache.org%3 >>>>>>>>> E >>>>>>>>> It should get you started as to how to register >>>>>>>>> extensionfunctionality in Fuseki. >>>>>>>>> >>>>>>>>> Adam Soroka >>>>>>>>>> On Dec 26, 2017, at 9:34 AM, Marc Agate <agate.marc@g >>>>>>>>>> mail.c >>>>>>>>>> om> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> Hi ! >>>>>>>>>> >>>>>>>>>> I successfully implemented sparql queries using >>>>>>>>>> custom ARQ >>>>>>>>>> functions >>>>>>>>>> using the following (custom function code): >>>>>>>>>> >>>>>>>>>> **************** >>>>>>>>>> public class LevenshteinFilter extends FunctionBase2 >>>>>>>>>> { >>>>>>>>>> >>>>>>>>>> public LevenshteinFilter() { super() ; } >>>>>>>>>> >>>>>>>>>> public NodeValue exec(NodeValue value1, >>>>>>>>>> NodeValue >>>>>>>>>> value2){ >>>>>>>>>> LevenshteinDistance LD=new >>>>>>>>>> LevenshteinDistance(); >>>>>>>>>> int i = LD.apply(value1.asString(), >>>>>>>>>> value2.asString()); >>>>>>>>>> return NodeValue.makeInteger(i); >>>>>>>>>> } >>>>>>>>>> } >>>>>>>>>> *************** >>>>>>>>>> >>>>>>>>>> it works fine when I query against a Model loaded >>>>>>>>>> from a >>>>>>>>>> turtle >>>>>>>>>> file, >>>>>>>>>> like this: >>>>>>>>>> >>>>>>>>>> *************** >>>>>>>>>> InputStream input = >>>>>>>>>> QueryProcessor.class.getClassLoader().getResourceAsSt >>>>>>>>>> ream(" >>>>>>>>>> full >>>>>>>>>> .t >>>>>>>>>> tl"); >>>>>>>>>> model = >>>>>>>>>> ModelFactory.createMemModelMaker().createModel("defau >>>>>>>>>> lt"); >>>>>>>>>> model.read(input,null,"TURTLE"); // >>>>>>>>>> null base >>>>>>>>>> URI, >>>>>>>>>> since >>>>>>>>>> model URIs are absolute >>>>>>>>>> input.close(); >>>>>>>>>> *************** >>>>>>>>>> >>>>>>>>>> with the query being sent like this : >>>>>>>>>> >>>>>>>>>> *************** >>>>>>>>>> String functionUri = "http://www.example1.org/Levensh >>>>>>>>>> teinFu >>>>>>>>>> ncti >>>>>>>>>> on >>>>>>>>>> "; >>>>>>>>>> FunctionRegistry.get().put(functionUri , >>>>>>>>>> LevenshteinFilter.class); >>>>>>>>>> >>>>>>>>>> String s = "whatever you want"; >>>>>>>>>> String sparql = prefixes+" SELECT DISTINCT >>>>>>>>>> ?l >>>>>>>>>> WHERE { >>>>>>>>>> ?x >>>>>>>>>> rdfs:label ?l . " >>>>>>>>>> + "FILTER(fct:LevenshteinFunction(?l, >>>>>>>>>> \"" + >>>>>>>>>> s >>>>>>>>>> + "\") >>>>>>>>>> < 4) }"; >>>>>>>>>> Query query = QueryFactory.create(sparql); >>>>>>>>>> QueryExecution qexec = >>>>>>>>>> QueryExecutionFactory.create(query, >>>>>>>>>> model); >>>>>>>>>> ResultSet rs = qexec.execSelect(); >>>>>>>>>> *************** >>>>>>>>>> >>>>>>>>>> However, if i use a working fuseki endpoint for the >>>>>>>>>> same >>>>>>>>>> dataset >>>>>>>>>> (full.ttl) like this : >>>>>>>>>> >>>>>>>>>> *************** >>>>>>>>>> fusekiUrl="http://localhost:3030/ds/query";; >>>>>>>>>> *************** >>>>>>>>>> >>>>>>>>>> sending the query like this (using >>>>>>>>>> QueryExecutionFactory.sparqlService(fusekiUrl,query) >>>>>>>>>> instead of >>>>>>>>>> QueryExecutionFactory.create(query,model) ): >>>>>>>>>> >>>>>>>>>> *************** >>>>>>>>>> String functionUri = "http://www.example1.org/Levensh >>>>>>>>>> teinFu >>>>>>>>>> ncti >>>>>>>>>> on >>>>>>>>>> "; >>>>>>>>>> FunctionRegistry.get().put(functionUri , >>>>>>>>>> LevenshteinFilter.class); >>>>>>>>>> >>>>>>>>>> String s = "whatever you want"; >>>>>>>>>> String sparql = prefixes+" SELECT DISTINCT >>>>>>>>>> ?l >>>>>>>>>> WHERE { >>>>>>>>>> ?x >>>>>>>>>> rdfs:label ?l . " + >>>>>>>>>> "FILTER(fct:LevenshteinFunction(?l, \"" >>>>>>>>>> + s >>>>>>>>>> + >>>>>>>>>> "\") >>>>>>>>>> < 4) }"; >>>>>>>>>> Query query = QueryFactory.create(sparql); >>>>>>>>>> QueryExecution qexec = >>>>>>>>>> QueryExecutionFactory.sparqlService(fusekiUrl,query); >>>>>>>>>> ResultSet rs = qexec.execSelect(); >>>>>>>>>> *************** >>>>>>>>>> >>>>>>>>>> Then I don't get any results back. In both cases I >>>>>>>>>> printed >>>>>>>>>> out >>>>>>>>>> the >>>>>>>>>> FunctionRegistry and they contain exactly the same >>>>>>>>>> entries, >>>>>>>>>> especially >>>>>>>>>> : >>>>>>>>>> >>>>>>>>>> key=http://www.example1.org/LevenshteinFunction >>>>>>>>>> value: >>>>>>>>>> org.apache.jena.sparql.function.FunctionFactoryAuto@5 >>>>>>>>>> a45133 >>>>>>>>>> e >>>>>>>>>> >>>>>>>>>> Any clue ? >>>>>>>>>> >>>>>>>>>> Thanks >>>>> >>>>>
