用户自定义ID Generator的例子

PO

package com.dsii.hibernate.po;

public class Company {
    private String id;
    private String name;
    private String year;

    public Company() {
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getYear() {
        return year;
    }

    public void setYear(String year) {
        this.year = year;
    }

}

XML

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
<hibernate-mapping>
   <class name="com.dsii.hibernate.po.Company" table="company" >
      <id name="id" column="id"  length="10">
         <generator class="com.dsii.hibernate.po.CustomizedIdGenerator">
                <param name="table">uid_table</param>
                <param name="column">next_hi_value_column</param>
                <param name="prefix">C</param>
        </generator>
      </id>
     
      <property name="name" column="name" length="30" />
      <property name="year" column="year" length="4" />
   </class>
</hibernate-mapping>


CustomizedIdGenerator
package com.dsii.hibernate.po;

import java.io.Serializable;
import java.sql.SQLException;
import java.util.Properties;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.dialect.Dialect;
import net.sf.hibernate.engine.SessionImplementor;
import net.sf.hibernate.type.Type;
import net.sf.hibernate.util.PropertiesHelper;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import net.sf.hibernate.id.TableGenerator;

public class CustomizedIdGenerator extends TableGenerator {

    private String prefix;

    private static final Log log = LogFactory.getLog(CustomizedIdGenerator.class);

    public void configure(Type type, Properties params, Dialect d) {
        super.configure(type, params, d);
        prefix = params.getProperty("prefix") == null ? "Pre" :
                 params.getProperty("prefix");
    }

    public synchronized Serializable generate(SessionImplementor session,
                                              Object obj) throws SQLException,
            HibernateException {
        Integer integer = (Integer)super.generate(session, obj);
        return prefix+integer;

    }

}


Bean
package com.dsii.hibernate.po;

import net.sf.hibernate.*;
import net.sf.hibernate.cfg.Configuration;
import net.sf.hibernate.tool.hbm2ddl.SchemaExport;


public class TestCompany {
    private static SessionFactory _sessions = null;

    static {
        try {
            Configuration cfg = new Configuration();
            cfg.addClass(Company.class);

            SchemaExport dbExport = new SchemaExport(cfg);
            dbExport.create(true, true);

            _sessions = cfg.buildSessionFactory();
        } catch (MappingException e) {
            e.printStackTrace();
        } catch (HibernateException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws HibernateException {
        System.out.println("----------------begin");

        Company c1 = new Company();
        c1.setName("dsii");
        c1.setYear("2004");
        Company c2 = new Company();
        c2.setName("dsii");
        c2.setYear("2004");


        Session session = _sessions.openSession();

        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            session.save(c1);
            session.save(c2);
            tx.commit();
        } catch (HibernateException he) {
            if (tx != null) {
                tx.rollback();
            }
            throw he;
        } finally {
            session.close();
        }
        System.out.println("----------------end");
    }


}