Java Hibernate，间接关系映射

我有两张桌子：单词和词干。第二个字段是单词的外键。这么多的词干可以属于一个词

在Java中，我创建了实体Word和Stem。因为word可以有许多词干，并且我对这些词干的列表进行了一些操作，所以我决定将这个列表和对应的方法放在单独的名为stemes的类中。此类的对象位于Word实体中。下面我将介绍我的代码的外观：

---

Word.java

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Transient
    protected Stems stems = new Stems();

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }

    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word")
    public List<Stem> getStems() {
        return stems.getStems();
    }
}

public class Stems {

    private List<Stem> stems = new ArrayList<>();

    public List<Stem> getStems() {
        return stems;
    }

    public void setStems(List<Stem> stems) {
        this.stems = stems;
    }
}

@Entity  
@Table(name = "Stems")  
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)  
@DiscriminatorColumn(name="Type",discriminatorType=DiscriminatorType.STRING)  
public abstract class Stem implements Cloneable{

    @Id
    @Column(name = "Stem", unique = true, nullable = false, length = 64)
    private String rawStem;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "WordId", nullable = false)
    private Word word;
}

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Embedded
    protected Stems stems = new Stems();

    public List<Stem> getStems() {
        return stems.getStems();
    }

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }
}

@Embeddable
public class Stems {
    // orphanRemoval removes stems which is present in database but not on list
    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word", orphanRemoval = true)
    private List<Stem> stems = new ArrayList<>();

    // getters/setters
}

---

---

我的问题来了。是否可以进行HQL查询以获得具有正确词干的单词？如果没有，那么如何实现这一点。也许这个结构不允许工作？如何添加/更新带有词干的单词？我尝试在word中设置词干数组，并在每个词干中设置单词id，然后使用session.merge（word），但它不起作用

我看到了光明。我想在这里粘贴我问题的完整解决方案。此解决方案仅允许在包含词干列表的word对象上调用session.merge来修改词干表

请注意@OneToMany注释中的注释@Embedded、@Embedded和参数删除

---

Word.java

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Transient
    protected Stems stems = new Stems();

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }

    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word")
    public List<Stem> getStems() {
        return stems.getStems();
    }
}

public class Stems {

    private List<Stem> stems = new ArrayList<>();

    public List<Stem> getStems() {
        return stems;
    }

    public void setStems(List<Stem> stems) {
        this.stems = stems;
    }
}

@Entity  
@Table(name = "Stems")  
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)  
@DiscriminatorColumn(name="Type",discriminatorType=DiscriminatorType.STRING)  
public abstract class Stem implements Cloneable{

    @Id
    @Column(name = "Stem", unique = true, nullable = false, length = 64)
    private String rawStem;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "WordId", nullable = false)
    private Word word;
}

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Embedded
    protected Stems stems = new Stems();

    public List<Stem> getStems() {
        return stems.getStems();
    }

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }
}

@Embeddable
public class Stems {
    // orphanRemoval removes stems which is present in database but not on list
    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word", orphanRemoval = true)
    private List<Stem> stems = new ArrayList<>();

    // getters/setters
}

@实体
@表（name=“Word”）
@继承（策略=InheritanceType.JOINED）
公共抽象类Word实现了可序列化{
//主键和其他列
@嵌入
受保护的杆=新杆（）；
公共列表getStems（）{
返回stems.getStems（）；
}
公共无效设置项（列表项）{
本.杆.设置杆（杆）；
}
}

stemes.java

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Transient
    protected Stems stems = new Stems();

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }

    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word")
    public List<Stem> getStems() {
        return stems.getStems();
    }
}

public class Stems {

    private List<Stem> stems = new ArrayList<>();

    public List<Stem> getStems() {
        return stems;
    }

    public void setStems(List<Stem> stems) {
        this.stems = stems;
    }
}

@Entity  
@Table(name = "Stems")  
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)  
@DiscriminatorColumn(name="Type",discriminatorType=DiscriminatorType.STRING)  
public abstract class Stem implements Cloneable{

    @Id
    @Column(name = "Stem", unique = true, nullable = false, length = 64)
    private String rawStem;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "WordId", nullable = false)
    private Word word;
}

@Entity
@Table(name = "Word")
@Inheritance(strategy=InheritanceType.JOINED)  
public abstract class Word implements Serializable{

    // primary key and other columns

    @Embedded
    protected Stems stems = new Stems();

    public List<Stem> getStems() {
        return stems.getStems();
    }

    public void setStems(List<Stem> stems) {
        this.stems.setStems(stems);
    }
}

@Embeddable
public class Stems {
    // orphanRemoval removes stems which is present in database but not on list
    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="word", orphanRemoval = true)
    private List<Stem> stems = new ArrayList<>();

    // getters/setters
}

@可嵌入
公共类词干{
//孤立删除将删除数据库中存在但不在列表中的茎
@OneToMany（cascade=CascadeType.ALL，fetch=FetchType.EAGER，mappedBy=“word”，orphan=true）
private List stees=new ArrayList（）；
//能手/二传手
}

Stem.java-无更改