@Entity
@Table(name="usertable")
@SuppressWarnings("serial")
@Searchable
public class User implements Serializable {

    @GeneratedValue(generator="userIdSeq")
    @SequenceGenerator(name="userIdSeq", sequenceName="usertable_id_seq")
    @SearchableId
    @Id
    int id;

    @SearchableProperty
    String userId;                      // 'Unique identifier. It is formed using this fashion: ''prefix:identifier''
    String userName;                    // Name used to log in the application.
    String email;                       // User's email

    @ManyToMany
    @JoinTable( name="usergroup",
                joinColumns=@JoinColumn(name = "userid", referencedColumnName="userId"),
                inverseJoinColumns=@JoinColumn(name = "groupid")
    )
    List<Group> groups;

    ...
}

// Group
@Entity
@Table(name="grouptable")
public class Group implements Serializable {
    @Id
    String groupId                  // Unique identifier for group.
    String description              // Brief text describing the group purposes.

    @ManyToMany(mappedBy="groups")
    @Cascade(SAVE_UPDATE)
    List<User> users

    ....
}

@Test
    @Transactional
    public void testGetUserByEmail(){
        Session session = factory.getCurrentSession();

        String email = "sarah.silverman@comedycentral.com";
        User user = createUser();
        user.setWeCanContact(true);
        user.setPartnersCanContact(false);
        user.setAgreedTerms(false);
        user.setReferer("Laura");

        String groupId = "AARP";
        String description = "Appletalk Address Resolution Protocol";
        Group group1 = new Group();
        group1.setGroupId(groupId);
        group1.setDescription(description);
        session.save(group1);
        session.flush();
        user.getGroupLists().add(group1);
        session.saveOrUpdate(user);

        User testUser = userRepository.getUserByEmail(email);
        assertNotNull(testUser);
        assertEquals("It's not the correct email", email, testUser.getEmail());
    }
    private User createUser(){
        Session session = factory.getCurrentSession();
        String userId = "UB:2010";
        String userPassword = "sarah";
        String realName = "Sarah Silverman";
        String email = "sarah.silverman@comedycentral.com";

        User user = new User();
        user.setUserId(userId);
        user.setUserName(email);
        user.setUserPassword(userPassword);
        user.setRealName(realName);
        user.setEmail(email);

        List<Group> emptyGroupLists = new ArrayList<Group>();
        user.setGroupLists(emptyGroupLists);
        Group group = new Group();
        group.setGroupId("ABC");
        group.setDescription("A for apple");
        user.getGroupLists().add(group);
        session.save(group);
        session.save(user);

        session.flush();
        return user;
    }
// Repository Method to get user from email
//
//  @NamedQuery(name="user.findByEmail",
//       query="SELECT u FROM User u " +
//    "LEFT JOIN FETCH u.groupLists " +
//              "WHERE upper(u.email) = :email")

public User getUserByEmail(String email) {
    Session session = sessionFactory.getCurrentSession();
    Query query = session.getNamedQuery("user.findByEmail");
    query.setParameter("email", email.toUpperCase());
    User user = (User)query.uniqueResult();
    return user;
}