java - 我无法删除 Jena 中数据类型属性的值

Question

我试图通过我在 java 中创建的接口(interface)删除实例的数据类型属性的值，但它不起作用。它给了我一个

Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException.

我不明白为什么。你能解释一下哪里出了问题吗？

这是我的按钮删除代码:

//Button Remove
public class ActionRemove implements ActionListener
{

    public void actionPerformed(ActionEvent evt)
    {

        StmtIterator iter = onto.model.listStatements();

        while (iter.hasNext()) 
        {
            Statement stmt  = iter.nextStatement(); 

            Resource  subject = stmt.getSubject(); 
            Property  predicate = stmt.getPredicate();  
            RDFNode object  = stmt.getObject();  
            if(subject.toString().equals (onto.uriBase+"#"+tabTF[0].getText()))
            {

                onto.model.remove(stmt);

            }

    }
}
}

我的完整代码:

import java.util.*;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.ontology.*;
import com.hp.hpl.jena.ontology.impl.*;
import com.hp.hpl.jena.util.*;
import java.io.*;
import java.awt.*;  
import java.awt.event.*; 
import com.hp.hpl.jena.vocabulary.RDF;
import com.hp.hpl.jena.vocabulary.XSD;
import com.hp.hpl.jena.util.iterator.ExtendedIterator;




public class FamilyModel extends Frame
{   
TextField[]tabTF=new TextField[4];
Button bAjout, bModifier, bSupprimer, bPrecedent, bSuivant, bRemove; //buttons Add, Remove, Previous, Next
OntModel model;
Onto onto;
int indice=0;
int p=0;
Resource p1; 


Button creerBouton(String S, int x, int y)
{
    Button b=new Button(S);
    add(b);         
    b.setBounds(x,y,120,30);
    return b;
}

void creerLabel(String etiquette, int x, int y)
{
    Label la=new Label(etiquette);
    la.setBounds(x,y,100,25);
    add(la);
}


public FamilyModel ()
{
        setLayout (null);
        setBackground (Color.pink);
        setBounds (100,200,900,450);
        addWindowListener(new FermerFenetre());

        creerLabel("Prenom : ",10,50);
        creerLabel("Nom : ",10,100);
        creerLabel("Date de Naissance: ",10,145);
        creerLabel("Genre (H ou F): ",10,190);

        //TextFields
        for(int i=0;i<4;i++)
        {
            tabTF[i]=new TextField("");
            tabTF[i].setBackground(Color.white);
            add(tabTF[i]);
        }
        tabTF[0].setBounds(120,45,150,25);
        tabTF[1].setBounds(120,100,150,25);
        tabTF[2].setBounds(120,145, 100,25);
        tabTF[3].setBounds(120,190, 45,25);

        bAjout=creerBouton("Ajouter",20,250); 
        setVisible(true);

        bModifier=creerBouton("Modifier",138,250); 
        setVisible(true);

        bSupprimer=creerBouton("Supprimer",250,250); 
        setVisible(true);

        bPrecedent=creerBouton("Precedent",360,250); 

        bSuivant=creerBouton("Suivant",450,250); 

        bRemove=creerBouton("Supprimer",600,250);

        setVisible(true);   

        onto = new Onto();

         readRDFfile();

        traitement(this);   

}



void traitement(Frame fenetre)
{

    bAjout.addActionListener(new ActionAjoutPersonne());
    bModifier.addActionListener(new ActionRemove());
    bSuivant.addActionListener(new ActionSuivant());
    bPrecedent.addActionListener(new ActionPrecedent());
    bRemove.addActionListener(new ActionRemove());

}


//Button Add
public class ActionAjoutPersonne implements ActionListener
{

    public void actionPerformed(ActionEvent evt)
    {


        p1=onto.model.createResource(onto.uriBase+"#"+tabTF[0].getText()); 
        p1.addProperty(onto.aPourPrenom, tabTF[0].getText());         
        p1.addProperty(onto.aPourNom, tabTF[1].getText());         
        p1.addProperty(onto.aDateNaiss, tabTF[2].getText()); 

        if (tabTF[3].getText().equals("F"))
        {
            p1.addProperty(onto.aGenre, tabTF[3].getText()); 
            p1.addProperty(RDF.type, onto.femme);

        }
        else if (tabTF[3].getText().equals("H"))
        {
            p1.addProperty(onto.aGenre, tabTF[3].getText());    
            p1.addProperty(RDF.type, onto.homme);
        }

        StringWriter sw = new StringWriter();
        onto.model.write(sw, "RDF/XML-ABBREV");
        String owlCode = sw.toString();
        File file = new File("d:/Onto.rdf");
        try{
            FileWriter fw = new FileWriter(file);
            fw.write(owlCode);
            fw.close();
        } catch(FileNotFoundException fnfe){
            fnfe.printStackTrace();} 
        catch(IOException ioe){
                ioe.printStackTrace();
        }  

    }
}



//Button Remove
public class ActionRemove implements ActionListener
{

    public void actionPerformed(ActionEvent evt)
    {

        StmtIterator iter = onto.model.listStatements();

        while (iter.hasNext()) 
        {
            Statement stmt  = iter.nextStatement(); 

            Resource  subject = stmt.getSubject(); 
            Property  predicate = stmt.getPredicate();  
            RDFNode object  = stmt.getObject();  
            if(subject.toString().equals (onto.uriBase+"#"+tabTF[0].getText()))
            {

                onto.model.remove(stmt);

            }

    }
  }
}


//Read Onto.rdf
public void readRDFfile()
{
     String inputFile="D:/Onto.rdf";
     try
     {
     InputStream in =new  FileInputStream(inputFile);
      if (in == null) {  
      System.out.println("File not found");
     }  
      onto.model.read(in," ");

     }catch(Exception e) {
           System.out.println("model.read catched error: " + e);
     }
}

//Button Next
class ActionSuivant implements ActionListener
{
    public void actionPerformed(ActionEvent evt)
    {

        ++indice;
        ExtendedIterator instances = onto.personne.listInstances();
        Individual instance = null;
        Individual firstInstance = null;
        for (p = 0; p < indice && instances.hasNext(); p++) {
            instance = (Individual) instances.next();
            if (firstInstance == null) {
                firstInstance = instance;
            }
        }    
        if (p < indice) {
            indice = 1;
            instance = firstInstance;
        }
        tabTF[0].setText(instance.getPropertyValue(onto.aPourPrenom).toString());
        tabTF[1].setText(instance.getPropertyValue(onto.aPourNom).toString());
        tabTF[2].setText(instance.getPropertyValue(onto.aDateNaiss).toString());
        tabTF[3].setText(instance.getPropertyValue(onto.aGenre).toString());
    }

} 

//Button Previous
class ActionPrecedent implements ActionListener
{
    public void actionPerformed(ActionEvent evt)
    {      
      --indice; 
      //Instances de la Classe Personne          
        ExtendedIterator instances=onto.personne.listInstances();

        Individual instance = null;
                for(p = 0; p < indice && instances.hasNext(); p++)
                {
                   instance = (Individual) instances.next();

                }   
                 tabTF[0].setText(instance.getPropertyValue(onto.aPourPrenom).toString());
                 tabTF[1].setText(instance.getPropertyValue(onto.aPourNom).toString());
                 tabTF[2].setText(instance.getPropertyValue(onto.aDateNaiss).toString());
                 tabTF[3].setText(instance.getPropertyValue(onto.aGenre).toString());

          }
} 


//Close window when X is pressed   
public class FermerFenetre extends WindowAdapter 
{

    public void windowClosing(WindowEvent evt)
    {
        if(evt.getWindow().getName().equals("frame0"))
        {
            System.exit(0);
        }
        else
        {
            evt.getWindow().dispose();
        }
    }
}


//Ontology
public class Onto 
{
    OntClass personne, genre, homme, femme, feminin, masculin, evenement, deces, mariage, divorce;
    OntModel model;
    String uriBase;
    ObjectProperty aPourFils, aPourFille, aGenre;
    DatatypeProperty aPourNom, aPourPrenom, aDateNaiss;

    public Onto (){
    model = ModelFactory.createOntologyModel( OntModelSpec.OWL_MEM_MICRO_RULE_INF );
    uriBase = "http://www.something.com/FAM";
    model.createOntology(uriBase);

    //Classes
    personne = model.createClass(uriBase+"personne");
    femme = model.createClass(uriBase+"femme");
    homme = model.createClass(uriBase+"homme");
    genre = model.createClass(uriBase+"genre");
    feminin = model.createClass(uriBase+"feminin");
    masculin = model.createClass(uriBase+"masculin");
    evenement = model.createClass(uriBase+"evenement");
    deces = model.createClass(uriBase+"deces");
    mariage = model.createClass(uriBase+"mariage");
    divorce = model.createClass(uriBase+"divorce");


    //Sub-classes
    genre.addSubClass(feminin);
    genre.addSubClass(masculin);
    personne.addSubClass(homme);
    personne.addSubClass(femme);
    evenement.addSubClass(deces);
    evenement.addSubClass(mariage);
    evenement.addSubClass(divorce);

    aPourFils = model.createObjectProperty(uriBase+"aPourFils");
    aPourFils.setDomain(personne);
    aPourFils.setRange(homme);

    aPourFille = model.createObjectProperty(uriBase+"aPourFille");
    aPourFille.setDomain(personne);
    aPourFille.setRange(femme);

    aGenre = model.createObjectProperty(uriBase+"aGenre");
    aGenre.setDomain(personne);
    aGenre.setRange(genre);

    aPourNom = model.createDatatypeProperty(uriBase+"aPourNom"); 
    aPourNom.setDomain(personne);
    aPourNom.setRange(XSD.xstring);

    aPourPrenom = model.createDatatypeProperty(uriBase+"aPourPrenom"); 
    aPourPrenom.setDomain(personne);
    aPourPrenom.setRange(XSD.xstring);

    aDateNaiss = model.createDatatypeProperty(uriBase+"aDateNaiss"); 
    aDateNaiss.setDomain(personne);
    aDateNaiss.setRange(XSD.xstring);
    }

}

public static void main(String args[]) 
{

    new FamilyModel();      
}
}

Answer 1

您已从集合中删除了一项，然后继续在其上使用之前的迭代器。

大多数 Java 集合迭代器都具有“快速失败”属性。一旦他们检测到基础集合已更改，他们将抛出 ConcurrentModificationException。

您的解决方案是执行两步删除过程:

1. 迭代并找到您需要删除的节点
2. 迭代要删除的节点列表(在第一步中找到)并实际从原始集合中删除它们。

代码(假设是 Java 5):

//Button Remove
public class ActionRemove implements ActionListener
{

    public void actionPerformed(ActionEvent evt)
    {
        List<Statement> statementsToRemove = new ArrayList<Statement>();

        // step 1
        StmtIterator iter = onto.model.listStatements();
        while (iter.hasNext()) 
        {
            Statement stmt  = iter.nextStatement(); 

            Resource  subject = stmt.getSubject(); 
            Property  predicate = stmt.getPredicate();  
            RDFNode object  = stmt.getObject();  
            if(subject.toString().equals (onto.uriBase+"#"+tabTF[0].getText()))
            {
                statementsToRemove.add(stmt);
            }
       }

       // step 2
       for( Statement stmt : statementsToRemove) 
       {
            onto.model.remove(stmt);
       }
   }
}

还有另一种方法(参见 http://download.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/CopyOnWriteArrayList.html 类)但是由于您的集合在 Jena api 中，您不能使用它；)。