package org.jpwh.model.collections.bagofstrings;

 import org.jpwh.model.Constants;

 import javax.persistence.CollectionTable;

 import javax.persistence.Column;

 import javax.persistence.ElementCollection;

 import javax.persistence.Entity;

 import javax.persistence.GeneratedValue;

 import javax.persistence.Id;

 import java.util.ArrayList;

 import java.util.Collection;

 @Entity

 public class Item {

     @Id

     @GeneratedValue(generator = Constants.ID_GENERATOR)

     protected Long id;

     @ElementCollection

     @CollectionTable(name = "IMAGE")

     @Column(name = "FILENAME")

     @org.hibernate.annotations.CollectionId( // Surrogate PK allows duplicates!

             columns = @Column(name = "IMAGE_ID"),

             type = @org.hibernate.annotations.Type(type = "long"),

             generator = Constants.ID_GENERATOR)

     protected Collection<String> images = new ArrayList<String>(); // No BagImpl in JDK!

     public Long getId() {

         return id;

     }

     public Collection<String> getImages() {

         return images;

     }

     public void setImages(Collection<String> images) {

         this.images = images;

     }

     // ...

 }

 package org.jpwh.test.collections;

 import org.jpwh.env.JPATest;

 import org.jpwh.model.collections.bagofstrings.Item;

 import org.testng.annotations.BeforeClass;

 import org.testng.annotations.Test;

 import javax.persistence.EntityManager;

 import javax.transaction.UserTransaction;

 import static org.testng.Assert.assertEquals;

 public class BagOfStrings extends JPATest {

     @Override

     public void configurePersistenceUnit() throws Exception {

         configurePersistenceUnit("BagOfStringsPU");

     }

     @Test

     public void storeLoadCollection() throws Exception {

         UserTransaction tx = TM.getUserTransaction();

         try {

             tx.begin();

             EntityManager em = JPA.createEntityManager();

             Item someItem = new Item();

             someItem.getImages().add("foo.jpg");

             someItem.getImages().add("bar.jpg");

             someItem.getImages().add("baz.jpg");

             someItem.getImages().add("baz.jpg");

             em.persist(someItem);

             tx.commit();

             em.close();

             Long ITEM_ID = someItem.getId();

             tx.begin();

             em = JPA.createEntityManager();

             Item item = em.find(Item.class, ITEM_ID);

             assertEquals(item.getImages().size(), 4);

             tx.commit();

             em.close();

         } finally {

             TM.rollback();

         }

     }

 }

 <persistence-unit name="BagOfStringsPU">

         <jta-data-source>myDS</jta-data-source>

         <class>org.jpwh.model</class>

         <class>org.jpwh.model.collections.bagofstrings.Item</class>

         <exclude-unlisted-classes>true</exclude-unlisted-classes>

     </persistence-unit>

 package org.jpwh.test.collections;

 import org.jpwh.env.JPATest;

 import org.jpwh.model.collections.bagofstrings.Item;

 import org.testng.annotations.BeforeClass;

 import org.testng.annotations.Test;

 import javax.persistence.EntityManager;

 import javax.transaction.UserTransaction;

 import static org.testng.Assert.assertEquals;

 public class BagOfStrings extends JPATest {

     @Override

     public void configurePersistenceUnit() throws Exception {

         configurePersistenceUnit("BagOfStringsPU");

     }

     @Test

     public void storeLoadCollection() throws Exception {

         UserTransaction tx = TM.getUserTransaction();

         try {

             tx.begin();

             EntityManager em = JPA.createEntityManager();

             Item someItem = new Item();

             someItem.getImages().add("foo.jpg");

             someItem.getImages().add("bar.jpg");

             someItem.getImages().add("baz.jpg");

             someItem.getImages().add("baz.jpg");

             em.persist(someItem);

             tx.commit();

             em.close();

             Long ITEM_ID = someItem.getId();

             tx.begin();

             em = JPA.createEntityManager();

             Item item = em.find(Item.class, ITEM_ID);

             assertEquals(item.getImages().size(), 4);

             tx.commit();

             em.close();

         } finally {

             TM.rollback();

         }

     }

 }