[英]Range queries in jena sparql?
我已經使用耶拿創建了一個rdf模型用於電子郵件存儲。。我的thr rdf代碼是:
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());
我已經將整數形式的MAIL_SIZE轉換為字符串,以將其存儲為rdf的屬性。現在,我想根據郵件大小執行范圍查詢:
SELECT ?resource
WHERE
{
?resource <MAIL_SIZE:> ?size .
FILTER (?size >= 24)
}
但是此查詢給出了錯誤...我知道這是由於我將MAIL_SIZE存儲為屬性,但是我不知道該怎么做? 如果我錯了,請糾正我,我真的很陌生嗎? 編輯: PS:我創建了我自己的屬性集。
//定義定義電子郵件rdf所需的所有屬性
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:" );
}
這是我查詢rdf模型的代碼。 在這種情況下,我從命令行獲取輸入,但是是的,字符串s查詢也可以...
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.
}
}
這顯示查詢工作:
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>> |
我問了一個我覺得非常相關的問題,即如何在Jena中使用整數而不是字符串,以便我可以查詢和過濾這些整數。 我得到了一個有用的答案,我認為它也可能對您有用。
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