Full source code is provided in the package: de.laliluna.component.collection1

In this example the component will have a defined order, which is guarantied by adding a position column to the database.

A hedgehog which is successful in life has of course many winter addresses.

Annotation mapping. 

import java.util.ArrayList;
import java.util.List;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import org.hibernate.annotations.CollectionOfElements;
import org.hibernate.annotations.IndexColumn;

@Entity
public class Hedgehog {

   @ElementCollection
   @CollectionTable(name = "hedgehog_winter_addresses",
      joinColumns = @JoinColumn(name = "hedgehog_id"))
    @OrderColumn(name = "list_index")
   //@IndexColumn(name = "list_index")
   private List<WinterAddress> addresses = new ArrayList<WinterAddress>();

@ElementCollection defines the component mapping. @CollectionTable is optional. It specifies the name of the table and the foreign key column. _@IndexColumn (Hibernate API) is optional and defines this relation as an indexed relation.

The WinterAddress should be made embeddable. If you do not make it embeddable, then the class will be serialized and written to a blob field. You can still read and write the objects, but they are not selectable in the database.

import java.io.Serializable;
import javax.persistence.Embeddable;

@Embeddable
public class WinterAddress implements Serializable{
   private String name;

   private String description;

XML mapping. 

<hibernate-mapping package="de.laliluna.component2">
  <class name="Hedgehog" table="thedgehog">
   ....... snip ........
    <list name="addresses" table="twinteraddress">
      <key column="hedgehog_id" not-null="true"></key>
      <list-index column="list_index"></list-index>
      <composite-element class="WinterAddress">
        <property name="name" type="string"></property>
        <property name="description" type="string"></property>
      </composite-element>
    </list>
  </class>
</hibernate-mapping>

Samples of use:

/* create and set components */
Hedgehog hedgehog = new Hedgehog("Peter");
WinterAddress address1 = new WinterAddress("stack of wood",
   "close to the apple tree");
WinterAddress address2 = new WinterAddress("shelter",
   "old shelter of the neighbour");
hedgehog.getAddresses().add(address1);
hedgehog.getAddresses().add(address2);
session.save(hedgehog);

/* select hedhehogs having a address named „first class hotel“*/
List<Hedgehog> list = session.createQuery
   ("from Hedgehog h left join h.addresses a where a.name = ?")
   .setString(0, "first class hotel").list();