hibernate简单操作

初步认识，只是简单的按照说明文档做了增删改查的Junit测试。
1.首先初始化一个Hibernate的sessionfactory，
private  static SessionFactory  hibernateSesseionFactory = createHiSessionFactory();
    //private static int count = 0;
    //单例模式
    private HibernateUtil(){
         
    }
     
    public synchronized static SessionFactory getHibernateSessionInstance(){
        if(hibernateSesseionFactory == null){
            hibernateSesseionFactory = createHiSessionFactory();
        }
         
        return hibernateSesseionFactory;
    }
     
    @SuppressWarnings("deprecation")
    public static SessionFactory createHiSessionFactory(){
        SessionFactory sessionFactory = null;
        try {
            sessionFactory =  new Configuration().configure().buildSessionFactory();
            //System.out.println("第 " + count + " 个");
        } catch (Exception e) {
 
            System.out.println("create hibernate session failed:" + e.getMessage());
        }
        return sessionFactory;
    }

2.创建相应的javabean，数据实体，使用注解的方案执行
@Entity
@Table(name="user")
public class User implements Serializable{
 
    private static final long serialVersionUID = 3517536107453191566L;
    private int userId;
    private String userName;
    private int age;
 
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    public int getUserId() {
        return userId;
    }
 
    public void setUserId(int userId) {
        this.userId = userId;
    }
 
    public String getUserName() {
        return userName;
    }
 
    public void setUserName(String userName) {
        this.userName = userName;
    }
 
    public int getAge() {
        return age;
    }
 
    public void setAge(int age) {
        this.age = age;
    }
 
    @Override
    public String toString() {
        return this.getUserId() + "--" + this.getUserName() + "--" + this.getAge();
    }
}

创建测试类：
private static SessionFactory sessionFactory = HibernateUtil.getHibernateSessionInstance();
 
@Ignore
@Test
public void testCreate(){
    //Session session = sessionFactory.getCurrentSession();
    Session session = sessionFactory.openSession();
    String name = "test";
    Long start = System.currentTimeMillis();
 
    for(int i = 0; i < 1000; i++){
        String userName = name + i;
        int age = 20;
        session.beginTransaction();
        User user = new User();
        user.setAge(age);
        user.setUserName(userName);
        session.save(user);
        session.getTransaction().commit();
    }
     
    System.out.println(System.currentTimeMillis() - start);
    session.close();
}
 
/**
 * 查所有
 */
@Ignore
@Test
public void testQuery(){
    Session session = sessionFactory.openSession();  //use getCurrentSession will encounter exception: createSQLQuery is not valid without active transaction
    //session.getTransaction().begin();
    List<Object> list = session.createQuery("from User where id  < 100").list();
    for(int i = 0; i < list.size(); i++){
        User user = (User) list.get(i);
        System.out.println(user.getUserName());
    }
    //session.getTransaction().commit();
    session.close();
 
}
 
 //hibernate的连表查询，在取数据表名的应避开mysql数据库中的关键名称
     @Test
    public void testQueryCondition2(){
        Session session = sessionFactory.openSession();
        String hql = "select users.userId, users.userName, users.age, orders.orderInfo, orders.ordersId from User  users left join Orders orders on orders.userId = users.userId where users.userName = :userName";
        Query query = session.createSQLQuery(hql);
        query.setString("userName", "test6");
        List<Object> list = query.list();
        for(int i = 0; i < list.size(); i++){
            Object user = list.get(i);
            System.out.println(user.toString());
        }
    }
//条件查询
@Test
public void testConditionQuery(){
    Session session = sessionFactory.openSession();
    //Criteria query = sesson.createCriteria(User.class).add(Restrictions.eq("userName", "test1"));
    Criteria query = session.createCriteria(User.class)
            //.add(Restrictions.like("userName", "%t1%"))
            .add(Restrictions.ilike("userName", "%update%"))
            .addOrder(Order.desc("userId"));
     
    List<User> list = query.list();
     
    session.getTransaction().begin();
    //获取符合条件的记录的主键
    for(int i = 0; i < list.size(); i++){
        int count = 1;
        User user = list.get(i);
        //session.delete(user); //delete object
        user.setUserName("update name" + i); //重置属性值
        session.update(user);  //更新属性值
        count++;
         
        System.out.println(user.toString());
    }
    session.getTransaction().commit();
     
     
}


//------------------------多对一表关系-------------------------//
	@Ignore
	@Test
	public void testOrder(){
		Session session = sessionFactory.getCurrentSession();
		Date date = new Date();
		
		try {
			for(int i = 1; i < 11; i++){
				for(int j = 0; j < 2; j++){
					if(i > 0){
						session = sessionFactory.openSession();
					}
					session.getTransaction().begin();
					Orders order = new Orders();
					order.setUserId(i);
					//order.setOrdersId((sdf.format(date)));
					
					order.setOrdersId("ORDERID" + i + j);
				
					order.setOrderInfo("this is orders from Amazon");
					System.out.println(order.toString());
					session.save(order);
					session.getTransaction().commit();
					//Thread.sleep(200000);
				}
			}
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}

		
		session.close();
	}


}

hibernate.cfg.xml中配置隐射实体



最后就可以通过简单的java代码来对数据库进行增删改查的操作