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.>and 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(HttpQuery.java:328 > ) at > org.apache.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.java:288) > at > org.apache.jena.sparql.engine.http.QueryEngineHTTP.execResultSetInner(Q > ueryEngineHTTP.java:348) at > org.apache.jena.sparql.engine.http.QueryEngineHTTP.execSelect(QueryEngi > 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.bdrc.io/funct >> 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/1cda23332af4264883e88697d994 >>>> 605770edcde2f93ddea51240e4b8@%3Cusers.jena.apache.org%3E >>>> 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 <[email protected]> >>>>> 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().getResourceAsStream("full >>>>> .t >>>>> tl"); >>>>> model = >>>>> ModelFactory.createMemModelMaker().createModel("default"); >>>>> 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/LevenshteinFuncti >>>>> 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/LevenshteinFuncti >>>>> 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@5a45133e >>>>> >>>>> Any clue ? >>>>> >>>>> Thanks
