How to pass parameter in genericgenerator of model to another class (IdGenerator)

Question

I want to use custom id generator in hibernate. This is my model:

@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
}

And my IdGenerator Class is :

    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_");
    }
}

My Goal is, I want that my IdGenerator Class can be used for all Entities/Models. Just need to change the paramters in entity.

My Question: How to catch the parameters in the IdGenerator Class? I want to get "pol_seq" and "POL-" in IdGenerator Class.

Hot Regard,

Tarmizi

score 3 · Accepted Answer · answered Sep 13 '18 at 10:07

That's what you've implemented the Configurable Interface for.

The configure() Method has these parameters in the Properties parameter. Look at its JavaDoc, it's basically a HashMap, so just do

params.getProperty("sequence_prefix");

And maybe you want to turn these names into constants, either public static final Strings, or better yet Enums.

How to pass parameter in genericgenerator of model to another class (IdGenerator)

1 Answers1