Question

我想在休眠状态下使用自定义ID生成器。这是我的模型：

@Entity(name="Poli")
@Table(name="POLI")
public class Poli extends DefaultEntityImpl implements Serializable{

    @Id 
    @GenericGenerator(
            name = "string-sequence", 
            strategy = "id.rekam.medis.service.generator.IdGenerator",
            parameters = {
                @org.hibernate.annotations.Parameter(
                    name = "sequence_name", 
                    value = "pol_seq"),
                @org.hibernate.annotations.Parameter(
                    name = "sequence_prefix", 
                    value = "POL-")                
            })
    @GeneratedValue(
            generator = "string-sequence",
            strategy = GenerationType.SEQUENCE)
    @Basic(optional = false)
    @Column(name = "ID",nullable = false)
    private String id;

    @Column(name = "NAMA", length = 10)
    private String nama;   

    //getter setter
}

我的IdGenerator类是：

    public class IdGenerator implements  IdentifierGenerator, Configurable {

    private static final Log logger = LogFactory.getLog(IdGenerator.class);
    private String sequenceName;
    private String sequencePrefix;
    public static final String SEQUENCE_PREFIX = "sequence_prefix";


    @Override
    public Serializable generate(SessionImplementor session, Object obj) throws HibernateException {
        Connection con = session.connection();
        Long nextValue = null;
        try {
            PreparedStatement p = con.prepareStatement(" SELECT POL_SEQ.NEXTVAL FROM DUAL ");
            ResultSet rs = p.executeQuery();
            while(rs.next()) {
                nextValue = rs.getLong("nextVal");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }

        if(logger.isDebugEnabled()) logger.debug("new id is generated:" + nextValue);

        return "POL-" + nextValue;
    }    

    @Override
    public void configure(Type type, Properties params, Dialect dlct) throws MappingException {
        sequencePrefix = ConfigurationHelper.getString(SEQUENCE_PREFIX, params,"SEQ_");
    }
}

我的目标是，我希望IdGenerator类可用于所有实体/模型。只需更改实体中的参数即可。

我的问题：如何在IdGenerator类中捕获参数？我想在IdGenerator类中获取“ pol_seq”和“ POL-”。

热烈问候

塔米兹

Answer 1

这就是您实现的Configurable接口的作用。

configure()方法在Properties参数中具有这些参数。 Look at its JavaDoc，它基本上是HashMap，所以只需

params.getProperty("sequence_prefix");

也许您想将这些名称转换为常量，或者是公共静态最终字符串，或者更好的是枚举。

如何将模型的genericgenerator中的参数传递给另一个类（IdGenerator）

1 个答案: