Question

我希望将EnumSet存储在mysql列中，类型为set：

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

  @Id
  @GeneratedValue
  @Column(nullable = false)
  @NotNull
  private String id;

  @Column(name = "types")
  private EnumSet<Type> types;

}

类型的枚举定义如下：

public enum Type {
  TYPE1,
  TYPE2,
  TYPE3,
  TYPE4,
  TYPE5
}

表格定义如下：

CREATE TABLE `ENTITY_TABLE` (
  `id` int(20) NOT NULL AUTO_INCREMENT,
  `types` set('TYPE1','TYPE2','TYPE3','TYPE4','TYPE5') DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

并在表格中插入：

INSERT INTO ENTITY_TABLE (types) VALUE ( 'TYPE1','TYPE2')

SET in mysql docs

Answer 1

非常感谢！我不得不使用你在这里稍微不同的版本。对我有用的是：

我有一个需要调整的Enum权限：

@Convert(converter = SetConverter.class)
@Column(name = "permission")
private EnumSet<Permission> permission;


//in a util and imported
...
@Converter
public static class SetConverter implements AttributeConverter<EnumSet<Permission>, String> {

    public String convertToDatabaseColumn(EnumSet<Permission> attribute) {
        StringBuilder sb = new StringBuilder();
        for (Permission c : attribute) { 
            sb.append(c + ",");
        }
        return sb.toString();
    }

    public EnumSet<Permission> convertToEntityAttribute(String dbData) {
        if (dbData == null) {
            dbData = "";
        }
        EnumSet<Permission> perm = EnumSet.of(Permission.DEFAULT); //default was a value I added.
        String[] persistencePermissions = StringUtils.trimAllWhitespace(dbData).toUpperCase().split(",");
        if (!StringUtils.isEmpty(StringUtils.trimAllWhitespace(dbData))) {
        try {
            for (String str : persistencePermissions) { 
            perm.add(Permission.valueOf(str));
        }}  
        catch (IllegalArgumentException IAE) {
            throw new Exception("INVALID_REQUEST");
        }}

        return perm;

    }

}

Answer 2

默认JPA-Set for Set

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

    @Id
    @GeneratedValue
    private String id;

    @ElementCollection
    @Enumerated(EnumType.STRING)
    @Column(name = "types")
    private Set<Type> types;

}

另一种可能性是使用AttributeConverter，但我从未尝试使用MySQL设置。

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

    @Id
    @GeneratedValue
    @Column(nullable = false)
    @NotNull
    private String id;

    @Convert(converter = SetConverter.class)
    @Column(name = "types")
    private EnumSet<Type> types;

}


@Converter
public class SetConverter implements AttributeConverter<EnumSet<Type>, String> {

    @Override
    public String convertToDatabaseColumn(EnumSet<Type> attribute) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public EnumSet<Type> convertToEntityAttribute(String dbData) {
        // TODO Auto-generated method stub
        return null;
    }

}

使用JPA 2.1将EnumSet映射到mysql

2 个答案: