<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="com.zattix.Messaggio" table="messaggi">
        <id name="id" type="int">
            <generator class="native" />
        </id>
        <many-to-one name="mittente" class="com.zattix.Utente" column="id_mittente" />
        <many-to-one name="destinatario" class="com.zattix.Utente" column="id_destinatario" fetch="select" />
        <property name="testo" type="text" />
        <property name="data" type="calendar" />
        <property name="eliminato" type="boolean" />
    </class>
</hibernate-mapping>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="com.zattix.Utente" table="utenti">
        <id name="id" type="int" column="idUtente">
            <generator class="native" />
        </id>
        <property name="username" type="string" length="15" />
        <property name="nome" type="string" length="30" />
        <property name="cognome" type="string" length="30" />
        <property name="password" type="string" length="40" />
        <property name="sesso" type="string" length="1" />
        <property name="data_registrazione" type="calendar" />
        <property name="data_nascita" type="calendar" />
        <property name="hash" type="string" length="40" />
        <property name="verificato" type="int" length="1" />
        <property name="immagine" type="string" length="45" />
        <many-to-one name="lingua" class="com.zattix.Lingua" />
        <many-to-one name="nazione" class="com.zattix.Nazione" />
        <many-to-one name="regione" class="com.zattix.Regione" />
        <many-to-one name="localita" class="com.zattix.Localita" />
        <bag name="accessi" table="UtentiAccessi" lazy="true">
            <key column="idUtente"/>
            <many-to-many column="idLogin" class="com.zattix.Login"/>
        </bag>
       
        <bag name="messaggi" cascade="all" inverse="true" lazy="true" order-by="data desc">
            <key column="id_destinatario"/>
            <one-to-many class="com.zattix.Messaggio" />
        </bag>

    </class>
</hibernate-mapping>

import javax.persistence.*;
@Entity
public class Player {
private long id;
private String nickName;
private Team team;

@ManyToOne
@JoinColumn(name="team_id")     
public Team getTeam() {return team;}
public void setTeam(Team t) {this.team = t;}
@Id
@GeneratedValue
public long getId() {return id;}
public void setId(long id) {this.id = id;}
public String getNickName() {return nickName;}
public void setNickName(String n) {nickName = n;}
}

import java.util.List; import javax.persistence.*;
@Entity
public class Team {
private long id;
private String name;
private List<Player> players;

@OneToMany(mappedBy="team", 
              targetEntity=Player.class,
    fetch=FetchType.EAGER, cascade = CascadeType.ALL)
public List<Player> getPlayers() {return players;}
public void setPlayers(List<Player> p){players=p;}
@Id
@GeneratedValue
public long getId() {return id;}
public void setId(long id) {this.id = id;}
public String getName() {return name;}
public void setName(String name) {this.name = name;}
}

public static void main(String args[]){
    HibernateUtil.recreateDatabase();
    Session session=HibernateUtil.beginTransaction();

    Team team = new Team();
    Player p1 = new Player();
    Player p2 = new Player();

    session.save(team);
    session.save(p1);
    session.save(p2);

    team.setName("Pickering Atoms");
    p1.setNickName("Lefty");
    p1.setTeam(team);
    p2.setNickName("Blinky");
    p2.setTeam(team);
    HibernateUtil.commitTransaction();
  }