我正在尝试通过我在java中创建的接口删除实例的数据类型属性值，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。你能解释一下我的错误吗？
以下是我删除按钮的代码：
//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();
}
}
答案 0 :(得分：5)
您已从集合中删除了某个项目，然后继续在其上使用以前的迭代器。
大多数java集合迭代器都具有“fail fast”属性。一旦他们检测到底层集合已经改变，他们将抛出ConcurrentModificationException。
您的解决方案是执行两步删除过程：
代码（假设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);
}
}
}
还有另一种方式（参见http://download.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/CopyOnWriteArrayList.html类），但由于你的收藏是在Jena api里面，你不能使用它;）。