基于hibernate对数据库操作封装

hibernate将数据库层抽象出来，且很方便的进行操作，本文对其进行了二次封装，方便调用。类图如下所示

 

将对于数据库的操作抽象成为泛型接口，BaseDao实现泛型接口，UserDao实例化泛型，DaoFactory包含有

所有对于实体操作对象，当需要对某个实体操作时，只需要调用相应的get方法即可。

IBaseDao<T>接口

public interface IBaseDao<T> {public boolean save(T obj);public boolean saveOrUpdate(T obj);public  boolean update(T domain);public boolean delete(T obj);public List<T> findByProperty(String propertyName,Object value);public List<T> findAll(String orderBy,boolean isAsc);public List<T> query(String sql);public int queryCount(String sql);public boolean executeSql(String sql);}

BaseDao<T>实现了接口

public class BaseDao<T> implements IBaseDao{private Class clazz;public BaseDao(Class clazz){this.clazz=clazz; }public Session getSession() {return HibernateSessionFactory.getSession();}public Transaction getTransaction() {return getSession().beginTransaction();}private String getTableName() {return clazz.getSimpleName();}@Overridepublic boolean save(Object obj) {Session session = null;try {session = getSession();session.beginTransaction();session.save(obj);session.getTransaction().commit();return true;} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();return false;} finally {if (session != null) {if (session.isOpen()) {// 关闭sessionsession.close();}}}}@Overridepublic boolean saveOrUpdate(Object obj) {Session session = null;try {session = getSession();session.beginTransaction();session.saveOrUpdate(obj);session.getTransaction().commit();return true;} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();return false;} finally {if (session != null) {if (session.isOpen()) {// 关闭sessionsession.close();}}}}@Overridepublic boolean update(Object obj) {Session session = null;try {session = getSession();session.beginTransaction();session.update(obj);session.getTransaction().commit();return true;} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();return false;} finally {if (session != null) {if (session.isOpen()) {// 关闭sessionsession.close();}}}}@Overridepublic boolean delete(Object obj) {Session session = null;try {session = getSession();session.beginTransaction();session.delete(obj);session.getTransaction().commit();return true;} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();return false;} finally {if (session != null) {if (session.isOpen()) {// 关闭sessionsession.close();}}}}@SuppressWarnings("unchecked")@Overridepublic List<T> findByProperty(String propertyName, Object value) {try {String queryString = "from " +getTableName()+ " as model where model." + propertyName + "= ?";Query queryObject = getSession().createQuery(queryString);queryObject.setParameter(0, value);return queryObject.list();} catch (RuntimeException re) {throw re;} finally {getSession().close();}}@SuppressWarnings("unchecked")@Overridepublic List<T> findAll(String orderBy, boolean isAsc) {try {String queryString = "from " + getTableName();if (isAsc) {queryString += " order by " + orderBy + " ASC";} else {queryString += " order by " + orderBy + " DESC";}Query queryObject = getSession().createQuery(queryString);return queryObject.list();} catch (RuntimeException re) {throw re;} finally {getSession().close();}}@SuppressWarnings("unchecked")@Overridepublic List<T> query(String sql) {try {SQLQuery queryObject = getSession().createSQLQuery(sql);queryObject.addEntity(clazz);return queryObject.list();} catch (RuntimeException re) {throw re;} finally {getSession().close();}}@Overridepublic int queryCount(String sql) {try {Query query = getSession().createSQLQuery(sql); BigInteger result = (BigInteger) query.uniqueResult(); return result.intValue();} catch (RuntimeException re) {throw re;} finally {getSession().close();}}@Overridepublic boolean executeSql(String sql) {Session session = null;try {session = getSession();session.beginTransaction();SQLQuery queryObject = session.createSQLQuery(sql);int rs = queryObject.executeUpdate();session.getTransaction().commit();if(rs<=0){return false;}} catch (RuntimeException re) {session.getTransaction().rollback();throw re;} finally {if (session != null) {if (session.isOpen()) {// 关闭sessionsession.close();}}}return true;}}

UserDao实例化泛型，并定义特殊的方法

public class UserDao extends BaseDao<User> {public UserDao(Class clazz) {super(clazz);}public List<User> findAllMen(){return findByProperty("sex", "男");}public List<User> findAllWomen(){return findByProperty("sex","女");}}

DaoFactory采用单例模式，并包含有所有对于实体的操作对象

public class DaoFactory {private static DaoFactory m_Instance = new DaoFactory();private UserDao userDao=null;private DaoFactory(){}public static DaoFactory getNewInstance(){return m_Instance;}public UserDao getUserDao(){if(userDao==null){userDao=new UserDao(User.class);}return userDao;}}

客户端调用

public static void main(String[]args){     DaoFactory dao=DaoFactory.getNewInstance();       UserDao user=dao.getUserDao();       List<User> list=user.findAllMen();       for(int i=0;i<list.size();i++){       System.out.println(list.get(i).getName());       }} 

对于hibernate的配置，可以参考http://blog.csdn.net/jiuqiyuliang/article/details/39380465