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();
	}

	@Override
	public 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session
					session.close();
				}
			}
		}
	}

	@Override
	public 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session
					session.close();
				}
			}
		}
	}

	@Override
	public 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session
					session.close();
				}
			}
		}
	}

	@Override
	public 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session
					session.close();
				}
			}
		}
	}

	@SuppressWarnings("unchecked")
	@Override
	public 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")
	@Override
	public 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")
	@Override
	public 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();
		}
	}

	@Override
	public 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();
		}
	}

	@Override
	public 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session
					session.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