Question

我想在RdfStreamer中加载RDF。我创建了一个查询，在arrayList中提取查询Sparql的结果集，我在流中获取它以传递给主类。这是我的流光代码：

package main.java.eu.larkc.csparql.sr4ld2014.streamer;
import java.util.ArrayList;
import java.util.Random;
import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.ResultSet;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.util.FileManager;
import eu.larkc.csparql.cep.api.RdfQuadruple;
import eu.larkc.csparql.cep.api.RdfStream;

public class SensorsStreamer extends RdfStream implements Runnable  {



    private long sleepTime;
    private String baseUri;
    private ArrayList<String> prova=new ArrayList<String>();


    public ArrayList<String> loadToFile(){
        Model modelMisurazioni= FileManager.get().loadModel("misurazioni.rdf");

        String s1 = "PREFIX  rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>\n" +
                "PREFIX  rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n" +
                "PREFIX  socrata: <http://www.socrata.com/rdf/terms#>\n" +
                "PREFIX  dcat: <http://www.w3.org/ns/dcat#>\n" +
                "PREFIX  ods: <http://open-data-standards.github.com/2012/01/open-data-standards#>\n" +
                "PREFIX  dcterm: <http://purl.org/dc/terms/>\n" +
                "PREFIX  geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>\n" +
                "PREFIX  skos: <http://www.w3.org/2004/02/skos/core#>\n" +
                "PREFIX  foaf: <http://xmlns.com/foaf/0.1/>\n" +
                "PREFIX  dsbase: <http://www.dati.lombardia.it/resource/>\n" +
                "PREFIX  ds: <http://www.dati.lombardia.it/resource/_647i-nhxk/>\n" +
                "\n" +
                "SELECT  ?idSensore \n" +
                "WHERE\n" +
                "  { ?s ?proprietà ?idSensore. "
                + "?s ds:idsensore ?idSensore.}\n" +
                "";
        Query queryM= QueryFactory.create(s1);
        QueryExecution qexec=QueryExecutionFactory.create(queryM, modelMisurazioni);

            System.out.println("QUERY 1");
            ResultSet results = qexec.execSelect();


            //ResultSetFormatter.out(System.out, results) ;

            int i=0;
            while(results.hasNext()){
            prova.add( results.next().getLiteral("idSensore").getLexicalForm() );
            System.out.println(prova.get(i++).toString() );
            }
return prova;
        }




    public SensorsStreamer(String iri, String baseUri,long sleepTime) {
        super(iri);
        this.sleepTime = sleepTime;
        this.baseUri = baseUri;
        prova=loadToFile();
    }




    public void run() {

        Random random = new Random();
        String sensorIndex;
        int subjectIndex;
        int roomIndex;
        int observationIndex;
        int numberOfPerson;

        while(true){
            try{

                numberOfPerson = random.nextInt(3);
                subjectIndex = random.nextInt(5);
                roomIndex = random.nextInt(5);
                observationIndex = random.nextInt(Integer.MAX_VALUE);

                RdfQuadruple q = new RdfQuadruple(baseUri + "sensor" + provva2, baseUri + "observes", baseUri + "observation" + observationIndex, System.currentTimeMillis());
                this.put(q);                
                if(numberOfPerson < 2){
                    q = new RdfQuadruple(baseUri + "observation" + observationIndex, baseUri + "who", baseUri+"person" + subjectIndex, System.currentTimeMillis());
                    this.put(q);
                } else {
                    for(int i = 0 ; i < numberOfPerson ; i++){
                        q = new RdfQuadruple(baseUri + "observation" + observationIndex, baseUri + "who", baseUri+"person" + subjectIndex, System.currentTimeMillis());
                        this.put(q);
                        subjectIndex = random.nextInt(5);
                    }
                }               
                q = new RdfQuadruple(baseUri + "observation" + observationIndex, baseUri + "where", baseUri+"room" + roomIndex, System.currentTimeMillis());
                this.put(q);

                Thread.sleep(sleepTime);

            } catch(Exception e){
                e.printStackTrace();
            }
        }

    }

}

日食的错误是这样的：

Exception in thread "main" java.lang.NoSuchMethodError: org.apache.jena.atlas.lib.Cache.getIfPresent(Ljava/lang/Object;)Ljava/lang/Object;
    at org.apache.jena.enhanced.EnhGraph.getNodeAs(EnhGraph.java:133)
    at org.apache.jena.rdf.model.impl.IteratorFactory.asResource(IteratorFactory.java:71)
    at org.apache.jena.rdf.model.impl.IteratorFactory.asResource(IteratorFactory.java:62)
    at org.apache.jena.rdf.model.impl.ModelCom.getResource(ModelCom.java:888)
    at org.apache.jena.rdf.model.impl.ModelCom.createResource(ModelCom.java:1338)
    at org.apache.jena.vocabulary.DC_11.<clinit>(DC_11.java:39)
    at org.apache.jena.assembler.assemblers.ContentAssembler.<clinit>(ContentAssembler.java:179)
    at org.apache.jena.assembler.ConstAssembler.content(ConstAssembler.java:73)
    at org.apache.jena.assembler.ConstAssembler.general(ConstAssembler.java:142)
    at org.apache.jena.sparql.core.assembler.AssemblerUtils.init(AssemblerUtils.java:59)
    at org.apache.jena.query.ARQ.init(ARQ.java:567)
    at org.apache.jena.sparql.system.InitARQ.start(InitARQ.java:29)
    at org.apache.jena.system.JenaSystem.lambda$init$40(JenaSystem.java:114)
    at java.util.ArrayList.forEach(Unknown Source)
    at org.apache.jena.system.JenaSystem.forEach(JenaSystem.java:179)
    at org.apache.jena.system.JenaSystem.forEach(JenaSystem.java:156)
    at org.apache.jena.system.JenaSystem.init(JenaSystem.java:111)
    at org.apache.jena.util.FileManager.<clinit>(FileManager.java:86)
    at main.java.eu.larkc.csparql.sr4ld2014.streamer.SensorsStreamer.loadToFile(SensorsStreamer.java:47)
    at main.java.eu.larkc.csparql.sr4ld2014.streamer.SensorsStreamer.<init>(SensorsStreamer.java:90)
    at main.java.eu.larkc.csparql.sr4ld2014.SR4LD2014_Ex4.main(SR4LD2014_Ex4.java:63)

我哪里错了？请帮帮我

Answer 1

检查lib/class org.apache.jena.atlas.lib.Cache.getIfPresent(Ljava/lang/Object;)Ljava/lang/Object。可能是Java选择了一个旧库，或者Cache.class没有实现这样的方法。尝试清理并重新编译。

在streamer CSparql中加载Rdf文件

1 个答案: