我是 Jena 的新手,对 Java 没有太多经验。我正在尝试制作一个从模型中删除语句的程序。(我知道使用图形和运行 SPARUL 查询的替代方法,但我想改用模型)。我曾尝试使用 model.remove(statement) 但似乎我没有正确执行它。我已经搜索了上述方法的示例,但找不到。有人可以帮我在哪里做错了吗?我想从删除一条语句开始。之后我想删除多个语句。我包括下面的代码。在此先感谢您的帮助
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Calendar;
import java.util.Date;
import com.hp.hpl.jena.query.Query;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.query.ResultSetFormatter;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.ResourceFactory;
import com.hp.hpl.jena.util.FileManager;
import com.hp.hpl.jena.vocabulary.VCARD;
public class Test3 extends Object {
public static void main(String[] args) throws IOException {
final String inputFileName = "vc-db-1.rdf";
Model model = ModelFactory.createDefaultModel();
InputStream in = FileManager.get().open(inputFileName);
if (in == null) {
throw new IllegalArgumentException ( "File: " + inputFileName + " not found");
}
model.read(new InputStreamReader(in), "");
in.close();
System.out.println( "== Before removal ==" );
model.write( System.out);
System.out.println( "\n\n== After removal ==" );
model.remove( model.createResource( "http://somewhere/JohnSmith" ),
VCARD.FN, // or ResourceFactory.createProperty( "http://www.w3.org/2001/vcard-rdf/3.0#FN" );
ResourceFactory.createTypedLiteral( "John Smith" ));
model.write( System.out);
}
}
输出如下
== Before removal ==
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" >
.....Other statements
<rdf:Description rdf:about="http://somewhere/JohnSmith/">
<vCard:N rdf:nodeID="A3"/>
<vCard:FN>John Smith</vCard:FN>
</rdf:Description>
<rdf:Description rdf:nodeID="A3">
<vCard:Given>John</vCard:Given>
<vCard:Family>Smith</vCard:Family>
</rdf:Description>
</rdf:RDF>
== After removal ==
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" >
...Other Statements
<rdf:Description rdf:about="http://somewhere/JohnSmith/">
<vCard:N rdf:nodeID="A3"/>
<vCard:FN>John Smith</vCard:FN>
</rdf:Description>
<rdf:Description rdf:nodeID="A3">
<vCard:Given>John</vCard:Given>
<vCard:Family>Smith</vCard:Family>
</rdf:Description>
</rdf:RDF>
删除语句后,我是否需要以某种方式“确认/提交”对模型的更改?