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同一张桌子上的* 多对多关系 *

这不是一个好主意。这是一场噩梦。

试试这个

@Entity
public class Friend {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer friendId;

    @Column
    private String name;

    @OneToMany(mappedBy="me")
    private List<MyFriends> myFriends;

}

@Entity
public class MyFriends {

    @EmbeddedId
    private MyFriendsId id;

    @Column
    private String additionalColumn;

    @ManyToOne
    @JoinColumn(name="ME_ID", insertable=false, updateable=false)
    private Friend me;

    @ManyToOne
    @JoinColumn(name="MY_FRIEND_ID", insertable=false, updateable=false)
    private Friend myFriend;

    @Embeddable
    public static class MyFriendsId implements Serializable {

        @Column(name="ME_ID", nullable=false, updateable=false)
        private Integer meId;

        @Column(name="MY_FRIEND_ID", nullable=false, updateable=false)
        private Integer myFriendId;

        public boolean equals(Object o) {
            if(o == null)
                return false;

            if(!(o instanceof MyFriendsId))
                return false;

            MyFriendsId other = (MyFriendsId) o;
            if(!(other.getMeId().equals(getMeId()))
                return false;

            if(!(other.getMyFriendId().equals(getMyFriendId()))
                return false;

            return true;
        }

        public int hashcode() {
            // hashcode impl
        }

    }


}

问候，