Hibernate/JPA中如何正确使用@OneToMany双向关系？

父类：
@Entity
<b>public</b> <b>class</b> Tournament implements Serializable {

    <b>private</b> <b>static</b> <b>final</b> <b>long</b> serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    <b>private</b> Long id;

    <b>private</b> String name;

    @OneToMany(cascade = CascadeType.ALL, 
            mappedBy = <font>"tournament"</font><font>, orphanRemoval = <b>true</b>)
    <b>private</b> List<TennisPlayer> tennisPlayers = <b>new</b> ArrayList<>();
</font>

子类：
@Entity
<b>public</b> <b>class</b> TennisPlayer implements Serializable {

    <b>private</b> <b>static</b> <b>final</b> <b>long</b> serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    <b>private</b> Long id;

    <b>private</b> String name;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = <font>"tournament_id"</font><font>)
    <b>private</b> Tournament tournament;

    <b>public</b> Long getId() {
        <b>return</b> id;
    }

    <b>public</b> <b>void</b> setId(Long id) {
        <b>this</b>.id = id;
    }

    <b>public</b> String getName() {
        <b>return</b> name;
    }

    <b>public</b> <b>void</b> setName(String name) {
        <b>this</b>.name = name;
    }

    <b>public</b> Tournament getTournament() {
        <b>return</b> tournament;
    }

    <b>public</b> <b>void</b> setTournament(Tournament tournament) {
        <b>this</b>.tournament = tournament;
    }

    @Override
    <b>public</b> <b>boolean</b> equals(Object obj) {
        <b>if</b> (<b>this</b> == obj) {
            <b>return</b> <b>true</b>;
        }
        <b>if</b> (!(obj instanceof TennisPlayer)) {
            <b>return</b> false;
        }
        <b>return</b> id != <b>null</b> && id.equals(((TennisPlayer) obj).id);        
    }

    @Override
    <b>public</b> <b>int</b> hashCode() {
        <b>return</b> 2018;
    }
}
</font>