過濾延遲初始化集合

Question

我的對象： 用戶和憑證 - 多對多關系，但用戶有一個參數

我想讓所有用戶在循環中獲得每個憑據的特定參數

要求：必須批量加載用戶。

• 簡單吧？

所以我有3個表：

@Table(name = "CRED")
public class Credential {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    @Column(name="CRED_ID")     
    Long credentialId;

    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "credential")
    @BatchSize(size = Search.DEFAULT_PAGE_SIZE)
    private Set<UserCredentialMapping> userCredentialMappingSet;  
}

@Table(name = "USER_CRED")
public class UserCredentialMapping {

    @JoinColumn(name = "user_id", referencedColumnName = "user_id")
    @ManyToOne
    @Filter(name="paramFilter", condition="param = :param")
    private User user;

    @JoinColumn(name = "cred_id", referencedColumnName = "cred_id")
    @ManyToOne
    private Credential credential;
}

@Table(name = "USER")
public class User  {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    @Column(name="USER_ID")     
    Long userId;

    @Column(name = "PARAM")
    String param
}

我在一個地方進行查詢並返回結果：

    String hqlQuery =   "select c from UserCredentialMapping m " +
        " inner join m.credential c" +
        " inner join m.user u" +
        " where u.param = :param" +
        " and c.user_id in (:users)" ;

        Session session = getSession();
        //desparetly trying to set filter
        session.enableFilter("paramFilter").setParameter("param", param);

    Query query = session.createQuery(hqlQuery);
    query.setParameterList("users", USERLIST);
    query.setParameter("param", someparam);

    List<Credential> credentialList = (List<Credential>)query.list();
    return credentialList;

平均時間對每個憑證進行一些處理，現在我需要獲得給定參數的用戶列表：

    for(Credential credential : credentialList){

        //following line makes hibernate query for users
        Iterator<CredentialMapping> mappingIterator = e.getUserCredentialMappingSet().iterator();

        while (mappingIterator.hasNext()){
            UserCredentialMapping userCred = mappingIterator.next();

            User user = userCred.getUser(); 
            DOEVILSTUFFTOINNOCENT(user);
    }

我的問題是迭代器生成SQL查詢，該查詢獲取憑證的所有用戶，而不是所有具有指定的憑證參數的用戶（換句話說，未應用過濾器）

有人建議如何使它工作？

謝謝 ！

Answer 1

我通過將ManyToMany映射添加到Credential類來解決它：

@ManyToMany(fetch = FetchType.LAZY)
@NotFound(action = NotFoundAction.IGNORE)
@JoinTable(name = "USER_CRED", 
    joinColumns = { 
        @JoinColumn(name = "CRED_ID") }, 
    inverseJoinColumns = { 
        @JoinColumn(name = "USER_ID") })
@Filter(name="param", condition="PARAM = :param")
@BatchSize(size = Search.DEFAULT_PAGE_SIZE)
private Set<User> users;

我無法通過UserCredentialMapping得到它......