Question

我使用jena为电子邮件存储创建了一个rdf模型。我的thr rdf的代码是：

Resource mail= model.createResource(msg.getMessageID())
            .addProperty(EMAILRDF.SUBJECT, subjec)  
            .addProperty(EMAILRDF.TO,receiveraddr)
            .addProperty(EMAILRDF.FROM,senderaddr)
            .addProperty(EMAILRDF.REC_NAME,receivername)
            .addProperty(EMAILRDF.SEND_NAME,sendername)
            .addProperty(EMAILRDF.ENCODING,encod)
            .addProperty(EMAILRDF.CONTENT,cont)
            .addProperty(EMAILRDF.DATE,dat)
            .addProperty(EMAILRDF.FOLDER_NAME,foldername)
            .addProperty(EMAILRDF.UID,uid)
            .addProperty(EMAILRDF.IN_REPLYTO,replyto)
            .addProperty(EMAILRDF.IN_REPLYTONAME,replyname)
            .addProperty(EMAILRDF.CC,cc)
            .addProperty(EMAILRDF.BCC,bcc)
            .addProperty(EMAILRDF.MAIL_SIZE,msize)  //here
            .addProperty(EMAILRDF.ATTACHEMENT_NAME,filename)
            .addProperty(EMAILRDF.ATTACHEMENT_NO,nos)
            .addProperty(EMAILRDF.CONTENT_TYPE,msg.getContentType());

我已将整数的MAIL_SIZE转换为字符串，以将其存储为rdf的属性。现在我想根据邮件大小执行范围查询：

SELECT ?resource
WHERE
  {
    ?resource <MAIL_SIZE:> ?size .
    FILTER (?size >= 24)
  }

但是这个查询给出了错误...我知道这是因为我将MAIL_SIZE存储为属性，但我不知道如何做到这一点？纠正我，如果我错了，我真的很擅长这个事情吗？的编辑： PS：我创建了自己的一组属性。

//定义制作电子邮件的rdf所需的所有属性

package email;
import com.hp.hpl.jena.rdf.model.*;


public class EMAILRDF {
    //Create a default model
    private static Model m = ModelFactory.createDefaultModel();

    //Subject of the mail
    public static final Property SUBJECT = m.createProperty("SUB:" );
    //Sender of the mail
    public static final Property FROM = m.createProperty("FROM:" );
    //Receiver of the mail
    public static final Property TO  = m.createProperty("TO:" );
    //Return path
    public static final Property RETURN_PATH = m.createProperty("RETURNPATH:" );
    //main contents of the mail
    public static final Property CONTENT = m.createProperty("CONTENT:" );
    //format of the mail
    public static final Property FORMAT = m.createProperty("FORMAT:" ); 
    //content type like html etc
    public static final Property CONTENT_TYPE = m.createProperty("CONTENTTYPE:" );
    //encoding in bits
    public static final Property ENCODING = m.createProperty("ENCODING:" );
    //date of the email
    public static final Property DATE = m.createProperty("DATE:" );      
    //CC of email   
    public static final Property CC = m.createProperty("CC:" ); 
    //BCC of email  
    public static final Property BCC = m.createProperty("BCC:" ); 
    //NAME OF THE SENDER
    public static final Property ATTACHEMENT_NAME = m.createProperty("ATTACHEMENTNAME:" );
    public static final Property ATTACHEMENT_NO = m.createProperty("ATTACHEMENTNO:" );   
    //SIZE OF MAIL  
    public static final Property MAIL_SIZE = m.createProperty("MAILSIZE:" );   
    //SIZE OF THE ATTACHEMENT of email  
    public static final Property ATTACHEMENT_SIZE = m.createProperty("ATTACHEMENTSIZE:" );   
    //MAIL TO WHICH PARTICULAR MAIL HAVE REPLIED    
    public static final Property IN_REPLYTO = m.createProperty("REPLIEDTO:" );
    public static final Property IN_REPLYTONAME = m.createProperty("REPLIEDTONAME:" );
    //FOLDER IN WHICH email EXISTS  
    public static final Property FOLDER_NAME = m.createProperty("FOLDERNAME:" );   
    //UID of email  
    public static final Property UID = m.createProperty("UID:" );   
   //name os receiver of email  
    public static final Property REC_NAME = m.createProperty("RECIEVERS_NAME:" );   
   //name of sender of email    
    public static final Property SEND_NAME = m.createProperty("SENDER_N AME:" );   





   }

这是我查询rdf模型的代码。在这里我从命令行接受输入但是字符串的查询也有效...

public class test4query extends Object {
    public static void main (String args[]) {
        String s;
        //load the dataset 
        //String query1; 
        //query1="hjcooljohny75@gmail.com";
        //query1 = (String)(subjectentry.getText());
          //  String s="SELECT ?x WHERE { ?x <TO:> '"+query1+"'}";

        String directory = "MYDATABASES/DATA2" ;
        Dataset ds = TDBFactory.createDataset(directory) ;
        Model model = ds.getDefaultModel() ;
        ds.begin(ReadWrite.READ) ;
        Scanner in = new Scanner(System.in);
         System.out.println("Enter a string");

            s = in.nextLine();
             //executeCmd(s) ;
            //UpdateAction.parseExecute(s,model);
            Query q =QueryFactory.create(s);
            QueryExecution qExec = QueryExecutionFactory.create(s, ds) ;
            //ResultSet rs = qExec.execSelect() ;
             QueryExecUtils.executeQuery(q, qExec) ;
         //   try {   
              //      ResultSetFormatter.out(rs) ;
               // } finally { qExec.close() ; }

            // Another query - same view of the data.

    }
}

这表明查询有效：

Enter a string
SELECT ?x WHERE { ?x <TO:> "hjcooljohny75@gmail.com" }
----------------------------------------------------------------------------------------
| x                                                                                    |
========================================================================================
| <<SEMA-CR-3-4MHV9RJ@bounce.oracle-mail.com>>                                         |
| <<20140526171614.1F2D61314F66@elabs10.com>>                                          |
| <<5833594959587942@mjinn.com>>                                                       |
| <<5x6p1e.hvnsvp7fhgxyo04mt@mail.payback.in>>                                         |

Answer 1

我问了一个我觉得非常相关的问题，关于如何使用Jena而不是字符串整数，以便我可以查询和过滤这些整数。我得到了一个有用的答案，我认为它对你也很有用。

Adding age (integer literals) to Jena RDF triples, and querying on them with SPARQL

jena sparql中的范围查询？

1 个答案: