RDF4j .ttl文件过滤IF语句

Question

我在编译期间遇到问题。你能帮忙解决问题吗？

`

public static void main(String[] args) throws IOException {

    File dir = new File("C:data\\test");

    String[] fileNames = dir.list();
    FileWriter outFile = new FileWriter("out.ttl");

    RDFWriter writer = org.eclipse.rdf4j.rio.Rio.createWriter(RDFFormat.TURTLE, outFile );

        writer.startRDF();
    for (String fileName : fileNames) {
        System.out.println("Reading from " + fileName);

        File f = new File(dir, fileName);

        Model data = Rio.parse(new FileInputStream(f), "", RDFFormat.TURTLE);
        for (Statement st: data) {
            if ( "efrbroo:F22_Self-Contained_Expression" != null ) { 
                        writer.handleStatement(st);
            }

        }
    }

    writer.endRDF();

}

`

这个问题的最初问题是：RDF4J data merge

Answer 1

您正在循环遍历Statement对象，这些对象是RDF语句的Java表示形式，或“三元组”。它有一个主题（可通过Statement.getSubject()获得），一个谓词（Statement.getPredicate()）和一个对象（Statement.getObject()）。请参阅https://rdf4j.eclipse.org/documentation/getting-started/更详细的介绍。

例如，如果你想删除所有以IRI http://example.org/F22_Self-Contained_Expression为对象的三元组，你可以这样做：

 IRI f22SelfContainedExpression = SimpleValueFactory.getInstance().createIRI("http://example.org/F22_Self-Contained_Expression"); 

 ... 

 if (!st.getObject().equals(f22SelfContainedExpression)) {
      writer.handleStatement(st);
 }