hibernate方便的操作数据库相当不错的 请各位下载看看啊

				//$Id: Boat.java,v 1.3 2004/12/08 20:05:15 epbernard Exp $				package org.hibernate.test.metadata;								import javax.ejb.Entity;				import javax.ejb.Id;				import javax.ejb.GeneratorType;				import javax.ejb.Inheritance;				import javax.ejb.InheritanceType;				import javax.ejb.InheritanceJoinColumn;				import javax.ejb.Column;				import java.io.Serializable;												/**				 * Boat class. Mapped in a Joined manner				 * 				 * @author Emmanuel Bernard				 */				@Entity()				@Inheritance(					strategy=InheritanceType.JOINED				)				public class Boat implements Serializable {					private Integer id;					private int size;									public Boat() {						super();					}										@Id(generate = GeneratorType.AUTO)					public Integer getId() {						return id;					}									@Column(name="boat_size")					public int getSize() {						return size;					}									public void setId(Integer integer) {						id = integer;					}									public void setSize(int i) {						size = i;					}				}