Need help implementing a data-based XML import

Yves · **Joined:** Mon Oct 24, 2005 9:16 am **Posts:** 7

I'm new to hibernate and I'm working on a project where I have to create a new database as well, so I'm using a forward engineering approach from classes to tables.

To create and load the database with test data at the same time, I created a class with a recursive method that reads a XML file, create the database (done automatically with the hbm2ddl.auto property) and populate the tables with data.

Here is the class that load the database:

Code:

public class TourManager {
   private Session s2;
   private Element rootElement;
   private String domain="tour";
   
   public static void main(String[] args) {
      TourManager mgr = new TourManager();
      mgr.loadDatabaseFromXml();
   }
   
   public void loadDatabaseFromXml() {
      Session session = HibernateSessionFactory.currentSession();
      s2 = session.getSession(EntityMode.DOM4J);
      InputStream in;
      try {
         in = new FileInputStream("f:\\tourdb.xml");
      } catch (IOException e) {
         throw new IllegalArgumentException("Could not parse XML document",e);
      }
      SAXReader reader = new SAXReader();
      Document document = null;
      try {
         document = reader.read(in);
      } catch (DocumentException e) {
         e.printStackTrace();
      }
      rootElement = document.getRootElement();
      System.out.println("Root Element="+rootElement.getName());
      recurLoadXml(rootElement);

   }
   public void recurLoadXml(Element elem) {
         Iterator j = elem.elementIterator();
         while (j.hasNext()) {
            Element e=(Element) j.next();
            recurLoadXml(e);
            s2.replicate(domain+"." + elem.getName(), elem, ReplicationMode.OVERWRITE);
         }
   }
}

The XML file looks like this:

Code:

<?xml version ="1.0" encoding="ISO-8859-1"?>
<TourDb>
   <id>1</id>
   <Tour>
      <id>1</id>
      <country>Mexico</country>
      <destination>Cancun</destination>
      <tourname>PARADISE REEF ADVENTURE</tourname>
      <categories>
         <elt>Adventure</elt>
         <elt>Snorkling</elt>
      </categories>
   </Tour>
   <Tour>
      <id>2</id>
      <country>Mexico</country>
      <destination>Cancun</destination>
      <tourname>INDIANA JOE`S ATV AND SPEED BOAT</tourname>
      <categories>
         <elt>Adventure</elt>
         <elt>Boat Ride</elt>
      </categories>
   </Tour>
</TourDb>

The mapping file looks like this:

Code:

<hibernate-mapping package="tour"> 
  <class name="Tour" table="tour" optimistic-lock="none"> 
    <id name="id" type="integer" unsaved-value="null" column="id">
      <generator class="native"/>
    </id>
    <property name="tourid" type="long" column="tourid"/>
    <property name="country" type="string" column="country"/>
    <property name="destination" type="string" column="destination"/>
    <property name="tourName" type="string" column="tour_name"/>
    <array name="categories" table="tour_categories" cascade="none"> 
      <key foreign-key="categories_id" column="categories_id"/>
      <list-index>
        <column name="idx" not-null="true"/>
      </list-index>
      <element type="string" column="elt"/>
    </array>
  </class>
</hibernate-mapping>

This works if categories are in a separate class/table. (Array would be replaced by a one-to-many tag in this case) But I want to store the categories in the tour_category table (generated by hb2ddl).

It looks like the replicate method only replicate entities, not relationships.

Any suggestion ?

Yves · **Joined:** Mon Oct 24, 2005 9:16 am **Posts:** 7

I made some modifications to the recursive function:

Code:

public void recurLoadXml(Element elem) {
      if (!elem.isTextOnly()) {
         if (elem.getParent()!=null ) {
            if( !elem.getParent().getName().equals(rootElement.getName())) {
               String sqlst="INSERT INTO  "+elem.getName().toLowerCase()+"_"+elem.getParent().getName().toLowerCase()+" VALUES ("+elem.getParent().elementText("id")+", " +
               elem.elementText("id")+")";
               System.out.println(sqlst);
               Connection con =s2.connection();
               try {
                  PreparedStatement res = con.prepareStatement(sqlst);
                  res.execute();
               } catch (SQLException e) {
                  e.printStackTrace();
               }   
            }
         }
         Iterator j = elem.elementIterator();
         while (j.hasNext()) {
            Element el=(Element) j.next();
            recurLoadXml(el);
         }
         s2.replicate(domain+"." + elem.getName(), elem, ReplicationMode.OVERWRITE);
      }
   }

Replicate does not process relationships so I added a native SQL to insert keys in children tables.

pksiv · **Posted:** Tue Oct 25, 2005 12:46 pm

Yves wrote:

Replicate does not process relationships so I added a native SQL to insert keys in children tables.

Replicate should process relationships if cascade="replicate" is specified.