jena

问题 I have an RDF/XML file like this: <rdf:RDF xmlns:go="http://www.geneontology.org/dtds/go.dtd#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <go:term rdf:about="http://www.geneontology.org/go#GO:0000001"> <go:accession>GO:0000001</go:accession> <go:name>mitochondrion inheritance</go:name> <go:synonym>mitochondrial inheritance</go:synonym> <go:definition>The distribution of mitochondria, including the mitochondrial genome, into daughter cells after mitosis or meiosis, mediated by

问题 I am using Jena in Spark. I am facing a weird issue when I am deploying on the cluster (Does not happen on local Dev, for which i do not need to build an uber jar) When I deploy on the cluster i get the following exceptions: Caused by: org.apache.jena.shared.NoReaderForLangException: Reader not found: JSON-LD at org.apache.jena.rdf.model.impl.RDFReaderFImpl.getReader(RDFReaderFImpl.java:61) at org.apache.jena.rdf.model.impl.ModelCom.read(ModelCom.java:305) 1 - I wonder, generally speaking

问题 I'm using TopBraid as IDE and Jena in Java. For the same SPARQL query and same file, I'm getting two different result sets. The ontology can be found here, https://dl.dropboxusercontent.com/u/108022472/ontology.owl The SPARQL is: select ?individual ?type ?label where { ?individual rdf:type ?type . ?individual rdfs:label ?label filter (?type in (wo:Kingdom)) } My Java Code: public class ExeSparql { static String prefix = "PREFIX owl: <http://www.w3.org/2002/07/owl#> " + "PREFIX xsd: <http:/

问题 I have my data organised in multiple graphs. The graph in which a triple is saved matters. The data structure is complicated but it can be simplified like this: My store contains cakes, where there's a hierarchy of different cake types, all subclasses of <cake> <http://example.com/a1> a <http://example.com/applecake> <http://example.com/a2> a <http://example.com/rainbowcake> ... Depending on how they get created by a user in a UI, they end up in a different graph. If for instance the user

问题 I just wondering how I can create new custom builtins for Jena. I know that for this purpose it should be used both the class "BaseBuiltin" and the class "BuiltinRegistry" (but how ?). I have also found out a plugin for Eclipse which is called "SADL" but I am not sure if I can use if for this purpose. If I can...which method is better and why ? Could anyone of you explain me which way I should take ? Cheers! 回答1: In a follow-up to a later question of yours, I provide code demonstrating the

问题 I'm trying to use federated queries with Jena via a Fuseki endpoint. With the SERVICE keyword in my SPARQL query, I'm connecting to a Stardog endpoint. As it's a secured URL, the endpoint is specified as follows: http://admin:admin@url. As this is not secure, Jena shows the following message: Code: 36/HAS_PASSWORD in USER: Including passwords in URIs is deprecated. According to the docs, you can specify srv:queryAuthUser and srv:queryAuthPwd for the credentials. Is there any way to do this

问题 I am new to Jena Fuseki server. According to the link http://jena.apache.org/documentation/serving_data/index.html, after I downloaded and unzipped it on my Fedora machine,I tried to start the server using command line. Under the Fuseki directory, the command should be like this: fuseki-server --update --mem /ds , yet it gave the error: fuseki-server command not found . Is there anyone who knows what the problem is? Thanks. 回答1: It works for me. Maybe you can read through the sequence below

问题 I am quite new to RDF and Jena. I want load a .nt (N- TRIPLE) file to a model. I have tried read(inputStream, "N-TRIPLE") but did not help. It throws org.apache.jena.riot.RiotException: Element or attribute do not match QName production: QName::=(NCName':')?NCName. Can anyone point me out what is wrong? Here is the link for the N-TRiple file which I tried to load : http://dbpedia.org/data/Berlin.ntriples 回答1: read(inputStream, string) uses the string argument as the base URI, not the syntax

问题 Hey i'm trying to make a web service and i'm using Jena distibution. At the moment i have created my model and its printing out in RDF/XML format. I want to get my data to a JSON file saved in my hard disk. How can i do that? 回答1: org.openjena.riot.out.RDFJSONWriter writes Talis-style RDF/JSON (i.e not JSON-LD). Look for a JSON-LD writer (I think there are ones that read RDF and write JSON-LD) Use SPARQL JSON Results format 回答2: Now the Jena RIOT readers/writers support also the RDF/JSON

问题 I am trying to use Jena to write to a local free standalone GraphDB (version 8.5.0) repository. What I have tried (1) Direct use from Jena I used this Jena 3.7.0 code snippet: String strInsert = "INSERT DATA {" + "<http://dbpedia.org/resource/Grace_Hopper> " + "<http://dbpedia.org/ontology/birthDate>" + " \"1906-12-9\"^^<http://www.w3.org/2001/XMLSchema#date> .}"; UpdateRequest updateRequest = UpdateFactory.create(strInsert); UpdateProcessor updateProcessor = UpdateExecutionFactory