hiberate通过类字段获取表字段

package com.jiesuan.common.hibernate3;import java.util.Iterator;import org.hibernate.cfg.Configuration;import org.hibernate.mapping.Column;import org.hibernate.mapping.PersistentClass;import org.hibernate.mapping.Property;import com.jiesuan.core.entity.User;/** * * @ClassName: HibernateConfigurationHelper    * @Description: TODO(通过类字段拿到表字段)    * @author Administrator    * @date 2011-12-8 下午12:00:24    * */public class HibernateConfigurationHelper {    private static Configuration hibernateConf;    @SuppressWarnings("unused")    private static Configuration getHibernateConf() {     if (hibernateConf == null) {      return new Configuration();     }     return hibernateConf;    }    @SuppressWarnings("unchecked")    private static PersistentClass getPersistentClass(Class clazz) {     synchronized (HibernateConfigurationHelper.class) {      PersistentClass pc = getHibernateConf().getClassMapping(        clazz.getName());      if (pc == null) {       hibernateConf = getHibernateConf().addClass(clazz);       pc = getHibernateConf().getClassMapping(clazz.getName());      }      return pc;     }    }    /**     * 功能描述：获取实体对应的表名     *     * @param clazz     *            实体类     * @return 表名     */    @SuppressWarnings("unchecked")    public static String getTableName(Class clazz) {     return getPersistentClass(clazz).getTable().getName();    }    /**     * 功能描述：获取实体对应表的主键字段名称     *     * @param clazz     *            实体类     * @return 主键字段名称     */    @SuppressWarnings("unchecked")    public static String getPkColumnName(Class clazz) {     return getPersistentClass(clazz).getTable().getPrimaryKey()       .getColumn(0).getName();    }    /**     * 功能描述：通过实体类和属性，获取实体类属性对应的表字段名称     *     * @param clazz     *            实体类     * @param propertyName     *            属性名称     * @return 字段名称     */    @SuppressWarnings("unchecked")    public static String getColumnName(Class clazz, String propertyName) {     PersistentClass persistentClass = getPersistentClass(clazz);     Property property = persistentClass.getProperty(propertyName);     Iterator it = property.getColumnIterator();     if (it.hasNext()) {      Column column = (Column) it.next();      return column.getName();     }     return null;    }    /**     * @param args     */    public static void main(String[] args) {   //  System.out.println(getTableName(IntelligenceNetVPNAndSCP.class));    System.out.println(getColumnName(User.class,      "id"));    }}