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在Hibernate 4中将表行映射到Enum值

[英]Mapping Table Rows to Enum Values in Hibernate 4

I have a table roles which has values such as admin , user , and others. 我有一个表roles ,其中包含adminuser和其他值。 I do not want to make it an ENUM type because I think the list might grow, shrink or change in the near future. 我不想将其设为ENUM类型,因为我认为列表可能会在不久的将来增长,缩小或更改。 I can't figure out a way to get Hibernate to Map directly to their respective enum types in my code automatically when I get the queried object. 当我得到查询的对象时,我想不出一种方法来自动将Hibernate直接映射到我的代码中各自的枚举类型。

Is there a standard approach to this? 有标准的方法吗?

EDIT: So basically, instead of storing the string in the row (which is what is on the DB), I want it to store the Enum when I query the DB. 编辑:因此,基本上,而不是将字符串存储在行中(这是数据库中的内容),我希望它在查询数据库时存储Enum。

public class enum UserType {
Admin("Admin"),
User("User");

private final String userType;

UserType(String userType) {
    this.userType = userType;
}

@Override
public String toString() {
    return userType;
}
}
@Entity
@Table(name = "user")
public class User {
    private Int id;
    private UserType userType;

public Int getId() {
    return id;
}
public void setId(Int id) {
    this.id = id;
}
public UserType getUserType() {
    return userType;
}
public void setUserType(UserType userType) {
    this.userType = userType;
}

} }

since theres no code provided so im gonna assume that you want to query a data by admin or user ? 由于没有提供代码,因此我将假定您要通过管理员或用户查询数据?

you can create an enum of role then include it to your entity class. 您可以创建一个角色枚举,然后将其包含在您的实体类中。

eg 例如

Enum 1: 枚举1:

public enum CardSuit implements Serializable{

        DIAMOND("Diamond"),HEART("Heart"),SPADE("Spade"),CLUB("Club");

        private String cardSuit;

        private CardSuit(String cardSuit){
            this.cardSuit = cardSuit;
        }

        public String toString(){
            return cardSuit;
        }

    }   

Enum 2: 枚举2:

public enum CardValue implements Serializable{

    ACE(1),TWO(2),THREE(3),FOUR(4),
    FIVE(5),SIX(6),SEVEN(7),EIGHT(8),
    NINE(9),TEN(10),JACK(10),QUEEN(10),KING(10);

    private int cardValue;

    private CardValue (int cardValue){
        this.cardValue = cardValue;
    }

    public int getValue(){
        return cardValue;
    }

    public String toString(){
        return String.valueOf(cardValue);
    }

}

this how i mapped enum type. 这是我如何映射枚举类型。

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

    private static final long serialVersionUID = 1L;

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

    @Enumerated(EnumType.STRING)
    @Column(name="CARD_VALUE")
    private CardValue cardValue;

    @Enumerated(EnumType.STRING)
    @Column(name="CARD_SUIT")
    private CardSuit cardSuit;

    //Setter & Getter ...

}

If you have knowledge about Criteria in Hibernate 如果您了解休眠标准

here is the example to query the Card by an enum: 这是通过枚举查询Card的示例:

sessionFactory.getCurrentSession()
            .createCriteria(Card.class)
            .add(Restrictions.eq("cardValue", CardValue.ACE))
            .list();

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