用户自定义ID Generator的例子

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; }

}

     uid_table next_hi_value_column C

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; }

   }

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");

   }

}