在ManyToMany关系中更新对象休眠

我的应用程序有2个通过ManyToMany关系链接的java pojo类：

@Entity
@Table(name = "user")
public class User implements Serializable {

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinTable(name = "user_match", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = { @JoinColumn(name = "match_id") })
    private Set<Season> followingSeason;

}

Season 班级

@Entity
@Table(name = "cricket_match")
public class Season implements Serializable{

@ManyToMany(mappedBy = "followingSeason", fetch = FetchType.EAGER)
    private Set<User> user;

}

在用户界面上，我有一个季节按钮，单击它可以与用户一起设置季节。db表中有一个预先存在的用户条目以及季节条目。基本上，我正在使用其他季节对象信息来更新用户对象。

if ("true".equalsIgnoreCase(followSeason)) {
Season season = new Season(); // I cannot instantiate a new season object here as it clears all the pre-existing entries of the season row of the entered season id. Do I load the season object first & then set it with the user object?
season.setSeasonId(SeasonId);
Set<Season> seasonSet = new HashSet<Season>();
seasonSet.add(season);
loggedInUser.setFollowingSeason(seasonSet); //loggedInUser is a User object
this.myService.followSeason(loggedInUser);

我无法在此处实例化新的季节对象，因为它清除了输入的季节ID的季节行的所有先前存在的条目。我是否要先从数据库加载季节对象，然后再将其与用户对象一起设置？我不确定这是否是正确的方法。

public void followSeason(User loggedInUser){
        sessionFactory.getCurrentSession().update(loggedInUser);
    }

从日志

Hibernate: delete from user_season where user_id=?
2015-12-30 18:16:03.0999 DEBUG http-bio-8080-exec-6 org.hibernate.persister.collection.AbstractCollectionPersister – Done deleting collection
2015-12-30 18:16:04.0005 DEBUG http-bio-8080-exec-6 org.hibernate.persister.collection.AbstractCollectionPersister – Inserting collection: [.User.followingSeason#1]
2015-12-30 18:16:04.0011 DEBUG http-bio-8080-exec-6 org.hibernate.SQL – insert into user_season (user_id, season_id) values (?, ?)
Hibernate: insert into user_season (user_id, season_id) values (?, ?)