Jena讀取Mysql數據的本體數據

前面有講到通過JenaAPI讀取RDF文件（或者OWL文件）存儲到mysql數據庫中，這是會默認生成7張表來存儲。具體流程如下：①加載數據庫JDBC驅動。②創建數據庫連接。③從Mysql數據庫讀取OntModel。④操作返回的OntModel，打印三元組查看具體內容。代碼如下：

package d2rq;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.hp.hpl.jena.db.DBConnection;
import com.hp.hpl.jena.db.IDBConnection;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.ModelMaker;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;

public class Mysql2Console {
    private static Logger log = LogManager.getLogger(Mysql2Console.class.getName());

    public static final String strDriver = "com.mysql.jdbc.Driver"; // path of
    public static final String strURL = "jdbc:mysql://localhost:3306/academic?useUnicode=true&characterEncoding=utf8"; // URL
    public static final String strUser = "root"; // database user id
    public static final String strPassWord = "123456"; // database password
    public static final String strDB = "MySQL"; // database type
    public static final String PATH = "doc/rdf/academic.rdf"; // file path
    public static final String OWL = "doc/owl/unit.owl"; // file path
    public static final String MODLE_NAME="MyOntology";
    /**
     * @param args
     * @throws ClassNotFoundException 
     */
    public static void main(String[] args) throws ClassNotFoundException {

        // 加載數據庫驅動類，需要處理異常
        Class.forName(strDriver);
        // 創建一個數據庫連接
        IDBConnection conn = getConnection(strURL, strUser, strPassWord,strDB);
        if(conn!=null){
            log.debug("-------mysql數據庫連接成功~");
        }
        //持久化到數據庫
         //createModel(conn,MODLE_NAME,PATH);           
        OntModel model = getModelFromRDB(conn, MODLE_NAME);
        log.debug(model+" :"+model.isEmpty());
        getTriples(model);

    }

    //獲取數據連接
      public static DBConnection getConnection(String dbUrl, String dbUser,  
                String dbPwd, String dbName) {  
            return new DBConnection(dbUrl, dbUser, dbPwd, dbName);   
        } 

    //從數據讀取OntModel
      public static OntModel getModelFromRDB(IDBConnection con,String name){
          ModelMaker maker = ModelFactory.createModelRDBMaker(con);
          Model model = maker.getModel(name);//讀取我們之前創建的MyOntology模型
          OntModelSpec spec = new OntModelSpec(OntModelSpec.RDFS_MEM);//這裏是指定的RDF格式 
          OntModel ontModel = ModelFactory.createOntologyModel(spec,model);
          return ontModel;
      }

      //
      public static void getTriples(OntModel model){
          StmtIterator stmIter=model.listStatements();
          while(stmIter.hasNext()){
              Statement stmt = stmIter.nextStatement();
              RDFNode object= stmt.getObject();
              if(object instanceof Resource){//主要爲了判定RDFNode是Resource還是Literal
                  log.debug(stmt.getSubject().getLocalName()+"--"
                          +stmt.getPredicate().getLocalName()+"--"
                          +object.asResource().getLocalName());
              }else{

                    log.debug(stmt.getSubject().getLocalName()+"**"
                            +stmt.getPredicate().getLocalName()+"**"
                            +object.toString());

              }

          }


      }

}

查詢結果如下：返回的模型不爲空，內容是三元組label-type-property.跟程序打印結果相同。個人感覺細節還待研究，有問題大家可以提出來，一起學習，謝謝。

2016-03-23 15:00:56.069 DEBUG [main][Mysql2Console.java:40] - -------mysql數據庫連接成功~
2016-03-23 15:00:57.250 DEBUG [main][Mysql2Console.java:45] - <ModelCom   {rdfs:label @rdf:type rdf:Property} | > :false
2016-03-23 15:00:57.253 DEBUG [main][Mysql2Console.java:72] - label--type--Property

於此同時我也讀取用Protege製作的people.owl文本到Mysql數據，然後讀取出來，這裏可以看到具體內容。
現在我們統計下表數據：

SELECT count(1) FROM jena_g1t1_stmt ; --1條記錄
SELECT count(1) FROM  jena_sys_stmt ; --51條記錄

具體需要更改的代碼如下：

public static final String PATH = "doc/owl/people.owl"; // file path
OntModelSpec spec = new OntModelSpec(OntModelSpec.OWL_MEM);//這裏是指定的OWL格式

執行完之後在做查詢：說明本體數據增加705條，元數據增加6條。

SELECT count(1) FROM jena_g1t1_stmt ; --706條記錄
SELECT count(1) FROM  jena_sys_stmt ; --57條記錄

現在我們用代碼繼續查詢Mysql數據讀取出來的OntModel模型和具體三元組信息代碼同上：

OntModel model = getModelFromRDB(conn, MODLE_NAME);
                log.debug(model+" :"+model.isEmpty());
                getTriples(model);

打印結果如下：因爲數據比較多這裏值複製部分日誌過來供參考。

2016-03-23 15:21:23.946 DEBUG [main][RDF2Mysql.java:67] - -------mysql數據庫連接成功~
2016-03-23 15:21:25.344 DEBUG [main][RDF2Mysql.java:72] - <ModelCom   {rdfs:label @rdf:type rdf:Property; http://owl.man.ac.uk/2006/07/sssw/people @rdf:type owl:Ontology; :drives @rdf:type owl:ObjectProperty; :drives @rdfs:label "drives"^^http://www.w3.org/2001/XMLSchema#string; :drives @rdfs:comment ""^^http://www.w3.org/2001/XMLSchema#string; :eaten_by @rdf:type owl:ObjectProperty; :eaten_by @rdfs:label "eaten_by"^^http://www.w3.org/2001/XMLSchema#string; :eaten_by @rdfs:comment ""^^http://www.w3.org/2001/XMLSchema#string; :eats @rdf:type owl:ObjectProperty; :eats @rdfs:label "eats"^^http://www.w3.org/2001/XMLSchema#string; :eats @rdfs:comment ""^^http://www.w3.org/2001/XMLSchema#string; :eats @rdfs:domain :animal; :eats @owl:inverseOf :eaten_by; :has_child @rdf:type owl:ObjectProperty; :has_child @rdfs:label "has_child"^^http://www.w3.org/2001/XMLSchema#string; :has_child @rdfs:comment ""^^http://www.w3.org/2001/XMLSchema#string; :has_father @rdf:type owl:ObjectProperty...} | > :false
2016-03-23 15:21:25.353 DEBUG [main][RDF2Mysql.java:168] - label--type--Property
2016-03-23 15:21:25.354 DEBUG [main][RDF2Mysql.java:168] - people--type--Ontology
2016-03-23 15:21:25.355 DEBUG [main][RDF2Mysql.java:168] - drives--type--ObjectProperty
2016-03-23 15:21:25.355 DEBUG [main][RDF2Mysql.java:173] - drives**label**drives^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.356 DEBUG [main][RDF2Mysql.java:173] - drives**comment**^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.356 DEBUG [main][RDF2Mysql.java:168] - eaten_by--type--ObjectProperty
2016-03-23 15:21:25.357 DEBUG [main][RDF2Mysql.java:173] - eaten_by**label**eaten_by^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.357 DEBUG [main][RDF2Mysql.java:173] - eaten_by**comment**^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.358 DEBUG [main][RDF2Mysql.java:168] - eats--type--ObjectProperty
2016-03-23 15:21:25.358 DEBUG [main][RDF2Mysql.java:173] - eats**label**eats^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.359 DEBUG [main][RDF2Mysql.java:173] - eats**comment**^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.359 DEBUG [main][RDF2Mysql.java:168] - eats--domain--animal
2016-03-23 15:21:25.360 DEBUG [main][RDF2Mysql.java:168] - eats--inverseOf--eaten_by
2016-03-23 15:21:25.360 DEBUG [main][RDF2Mysql.java:168] - has_child--type--ObjectProperty
2016-03-23 15:21:25.360 DEBUG [main][RDF2Mysql.java:173] - has_child**label**has_child^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.361 DEBUG [main][RDF2Mysql.java:173] - has_child**comment**^^http://www.w3.org/2001/XMLSchema#string
2016-03-23 15:21:25.361 DEBUG [main][RDF2Mysql.java:168] - has_father--type--ObjectProperty
2016-03-23 15:21:25.362 DEBUG [main][RDF2Mysql.java:173] - has_father**label**has_father^^http://www.w3.org/2001/XMLSchema#string

如果需要讀取Ontology所有的類和屬性執行下面方法。

  //讀取Ontology的本體所有的類和屬性
      public static void getClasses(OntModel model) {  
            for (ExtendedIterator<OntClass> ei = model.listClasses(); ei.hasNext();) {  
                OntClass oc = ei.next();  
                System.out.println(oc.getLocalName());  
                for (ExtendedIterator<OntProperty> eip = oc  
                        .listDeclaredProperties(); eip.hasNext();) {  
                    OntProperty op = eip.next();  
                   log.debug(op.getLocalName());  
                }  
            }  
        }

日誌如下：

2016-03-23 15:24:24.495 DEBUG [main][RDF2Mysql.java:157] - has_parent
2016-03-23 15:24:24.497 DEBUG [main][RDF2Mysql.java:157] - has_mother
2016-03-23 15:24:24.499 DEBUG [main][RDF2Mysql.java:157] - is_pet_of
2016-03-23 15:24:24.502 DEBUG [main][RDF2Mysql.java:157] - part_of
null
2016-03-23 15:24:24.519 DEBUG [main][RDF2Mysql.java:157] - eaten_by
2016-03-23 15:24:24.520 DEBUG [main][RDF2Mysql.java:157] - works_for

如果只想要輸出類信息執行下面代碼：這樣就不是把謂語和賓語打印出來。遍歷所有的類即可。

 public static void printModel(OntModel model){
          for (Iterator<OntClass> i = model.listClasses(); i.hasNext();) {
            OntClass oc = i.next();  
            log.debug(oc.getLocalName());  
        }  
      }

輸出信息如下：

2016-03-23 15:25:20.907 DEBUG [main][RDF2Mysql.java:67] - -------mysql數據庫連接成功~
2016-03-23 15:25:22.099 DEBUG [main][RDF2Mysql.java:146] - adult
2016-03-23 15:25:22.102 DEBUG [main][RDF2Mysql.java:146] - animal
2016-03-23 15:25:22.105 DEBUG [main][RDF2Mysql.java:146] - animal_lover
2016-03-23 15:25:22.108 DEBUG [main][RDF2Mysql.java:146] - null
2016-03-23 15:25:22.111 DEBUG [main][RDF2Mysql.java:146] - bicycle

今天就寫到這裏，如果對你有幫助請點個贊，如果有任何技術問題歡迎指正，謝謝~

Jena讀取Mysql數據的本體數據

Spring Cloud 部署時如何使用 Kubernetes 作爲註冊中心和配置中心

D2RQ之Linked data

Jena讀取Mysql數據的本體數據

java IO 流操作

java程序員的加冕之路~

Mysql驅動不匹配

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結