Question

我有2个实体类作为帐户和邮件，它们通过@ManyToMany相互连接。帐户实体有许多邮件实体，而邮件实体有许多帐户实体。我需要从邮件中获取邮件的密件抄送。

我的标准如下;

Criteria criteria = sessionFactory.getCurrentSession().createCriteria(Mail.class, "t");
        criteria.setProjection(Projections.projectionList()
                  .add(Projections.property("mailId"), "mailId")
                  .add(Projections.property("title"), "title")
                ).setResultTransformer(Transformers .aliasToBean(Mail.class));
        List<Mail> Mails = (List<Mail>)criteria.list();

但是当我添加 .add（Projections.property（＆＃34;来自＆＃34;），＆＃34;来自＆＃34;） 此代码时，试图从＆＃34;，＆＃34; cc＆＃34;中获取Set＆＃34;或者＆＃34; bcc＆＃34;，我收到错误，我搜索得太多但我找不到成功的方法。

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

    private static final long serialVersionUID = -1196398352385977136L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "MAIL_ID")
    private Integer mailId;


@ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinTable(name = "MAIL_FROM_ACCOUNT", joinColumns = { @JoinColumn(name = "MAIL_ID") }, inverseJoinColumns = {
        @JoinColumn(name = "ACCOUNT_ID") })
private Set<Account> from = new HashSet<Account>(0);

@ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinTable(name = "MAIL_TO_ACCOUNT", joinColumns = { @JoinColumn(name = "MAIL_ID") }, inverseJoinColumns = {
        @JoinColumn(name = "ACCOUNT_ID") })
private Set<Account> to = new HashSet<Account>(0);


@ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinTable(name = "MAIL_BCC_ACCOUNT", joinColumns = { @JoinColumn(name = "MAIL_ID") }, inverseJoinColumns = {
        @JoinColumn(name = "ACCOUNT_ID") })
private Set<Account> bcc = new HashSet<Account>(0);

和我的其他班级

@Entity
@Table(name = "ACCOUNT")
public class Account implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = -6230400682491920993L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ACCOUNT_ID")
    private int accountId;

@ManyToMany(mappedBy = "from", fetch = FetchType.LAZY)
private Set<Mail> fromMails = new HashSet<Mail>(0);

@ManyToMany(mappedBy = "to", fetch = FetchType.LAZY)
private Set<Mail> toMails = new HashSet<Mail>(0);

@ManyToMany(mappedBy = "to", fetch = FetchType.LAZY)
private Set<Mail> bccMails = new HashSet<Mail>(0);

//getter and setters

java.lang.ArrayIndexOutOfBoundsException：2 在org.hibernate.loader.criteria.CriteriaLoader.getResultRow（CriteriaLoader.java:161）在org.hibernate.loader.criteria.CriteriaLoader.getResultColumnOrRow（CriteriaLoader.java:141）在org.hibernate.loader.Loader.getRowFromResultSet（Loader.java:756）在org.hibernate.loader.Loader.processResultSet（Loader.java:972）在org.hibernate.loader.Loader.doQuery（Loader.java:930）在org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections（Loader.java:336）在org.hibernate.loader.Loader.doList（Loader.java:2617）在org.hibernate.loader.Loader.doList（Loader.java:2600）在org.hibernate.loader.Loader.listIgnoreQueryCache（Loader.java:2429）在org.hibernate.loader.Loader.list（Loader.java:2424）在org.hibernate.loader.criteria.CriteriaLoader.list（CriteriaLoader.java:109）在org.hibernate.internal.SessionImpl.list（SessionImpl.java:1774）在org.hibernate.internal.CriteriaImpl.list（CriteriaImpl.java:363）

Hibernate Projections设置<object> @ManyToMany

0 个答案: