Orm 读取EBean中具有复合键的批注时出错

此后

我想使用OneToMany而不是ManyToMany注释，让中产阶级使用Ebean使用复合键。我有一个错误：

java.lang.RuntimeException:读取models.SoftwareTagPk的注释时出错

这是我的SoftwareTagPk类：

@Embeddable
public class SoftwareTagPk  implements Serializable {

    @ManyToOne
    private Tag tag;

    @ManyToOne
    private Software software;

    ...
}

和SoftwareTag类：

@Entity
public class SoftwareTag extends Model {

    @EmbeddedId
    private SoftwareTagPk pk = new SoftwareTagPk();

    @Transient
    public Tag getTag() {
        return pk.getTag();
    }

    public void setTag(Tag aTag) {
        pk.setTag(aTag);
    }

    @Transient
    public Software getSoftware() {
        return pk.getSoftware();
    }

    public void setSoftware(Software aSoftware) {
        pk.setSoftware(aSoftware);
    } 
}

也在日志中：

与来自的[class models.Tag]关联时出错 [models.SoftwareTagPk.tag]。类模型.标记是否已注册

---

如何修复它？

要使此代码正常工作，您必须执行以下操作：

在您的

SoftwareTagPk

类中，仅放置标签和软件的id

将

@ManyToOne

关系移动到

SoftwareTag

类

添加属性

可更新的
和
可插入的
设置为false的
@JoinColumn
注释

覆盖

SoftwareTag

类中的设置器

setTag

和

setSoftware

。在这些设置程序中，您将把id重写为复合密钥

该解决方案的主要思想是，

SoftwareTag

具有复合密钥和

@manytone

关系，并且它们被映射到相同的collumns

代码如下：

Tag.java

@Entity 
public class Tag extends Model {
    @Id
    private Integer id;

    @OneToMany(mappedBy="tag")
    public List<SoftwareTag> softwareTags;

    public Integer getId() {
        return id;
    }

    public void setId(Integer aId) {
        id=aId;
    }

    public static Finder<Integer,Tag> find = new Finder<Integer,Tag>(
        Integer.class, Tag.class
    ); 
} 

SoftwareTagPk.java

@Embeddable
public class SoftwareTagPk implements Serializable {

    public Integer tag_id;

    public Integer software_id;

    @Override
    public int hashCode() {
        return tag_id + software_id;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) 
            return true;
        SoftwareTagPk pk = (SoftwareTagPk)obj;
        if(pk == null)
            return false;
        if (pk.tag_id.equals(tag_id) && pk.software_id.equals(software_id)) {
            return true;
        }
        return false;
    }
}

@Entity
public class SoftwareTag extends Model {

    SoftwareTag() {
        pk = new SoftwareTagPk();       
    }

    @EmbeddedId
    private SoftwareTagPk pk = new SoftwareTagPk();

    @ManyToOne
    @JoinColumn(name = "tag_id", insertable = false, updatable = false)
    private Tag tag;

    @ManyToOne
    @JoinColumn(name = "software_id", insertable = false, updatable = false)
    private Software software;

    public Tag getTag() {
        return tag;
    }

    public void setTag(Tag aTag) {
        tag = aTag;
        pk.tag_id = aTag.getId();
    }

    public Software getSoftware() {
        return software;
    }

    public void setSoftware(Software aSoftware) {
        software = aSoftware;
        pk.software_id = aSoftware.getId();
    }
}

@Embeddable
public class SoftwareTagPk implements Serializable {

    public Integer tag_id;

    public Integer software_id;

    @Override
    public int hashCode() {
        return tag_id + software_id;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) 
            return true;
        SoftwareTagPk pk = (SoftwareTagPk)obj;
        if(pk == null)
            return false;
        if (pk.tag_id.equals(tag_id) && pk.software_id.equals(software_id)) {
            return true;
        }
        return false;
    }
}