hibernate学习-CURD-第3天

向右看齐 2022-01-31 04:01 175阅读 0赞

代码地址：[https://github.com/MisterChegy/hibernate][https_github.com_MisterChegy_hibernate]

1、工具类的创建  
每次在获取 Session 时，都需要通过 Configuration 对象加载主配置文件与映射文件，并  
且要创建 SessionFactory 对象，降低了开发与执行效率。所以，对于 Session 对象的获取，  
可以创建一个工具类。

public class HbnUtils {
    	private static SessionFactory sessionfactory;
    	
    	public static Session getSession(){
    		return getSessionFactory().getCurrentSession();
    	}
    	public static SessionFactory getSessionFactory(){
            
    		if(sessionfactory==null||sessionfactory.isClosed()){
    			sessionfactory=new Configuration().configure().buildSessionFactory();
    			
    		}
    		return sessionfactory;
    		
    	
    	}
    }

2、CURD 测试  
在 上一个项目的基础上，再创建一个测试类 Test。在其中通过使用工具类 HbnUtil  
来测试增、删、改，与简单查询操作。

// save
    	@Test
    	public void saveStudent() {
    		Student s1 = new Student();
    		s1.setSname("进行插入操作");
    		Session session = HbnUtils.getSession();
    		try {
    			session.beginTransaction();
    			session.save(s1);
    			System.out.println(s1.getSname());
    			session.getTransaction().commit();
    
    		} catch (Exception ex) {
    			ex.printStackTrace();
    			session.getTransaction().rollback();
    		}
    		System.out.println(s1.getSname());
    
    	}
    
    	// delete
    	@Test
    	public void deleteStudent() {
    		Student s1 = new Student();
    		s1.setSid(1);
    		Session session = HbnUtils.getSession();
    		try {
    			session.beginTransaction();
    			session.delete(s1);
    			session.getTransaction().commit();
    
    		} catch (Exception ex) {
    			ex.printStackTrace();
    			session.getTransaction().rollback();
    		}
    		System.out.println(s1.getSname());
    
    	}
    
    	// update
    	@Test
    	public void updateStudent() {
    		Student s1 = new Student();
    		s1.setSname("update");
    		s1.setSid(2);
    		Session session = HbnUtils.getSession();
    		try {
    			session.beginTransaction();
    			session.update(s1);
    			session.getTransaction().commit();
    
    		} catch (Exception ex) {
    			ex.printStackTrace();
    			session.getTransaction().rollback();
    		}
    
    	}
    
    	// load
    	@Test
    	public void loadStudent() {
    
    		Session session = HbnUtils.getSession();
    		try {
    
    			session.beginTransaction();
    			Student s1 = session.load(Student.class, 1);
    			System.out.println(s1.getSname() + s1.getSid());
    
    			session.getTransaction().commit();
    
    		} catch (Exception ex) {
    			ex.printStackTrace();
    			session.getTransaction().rollback();
    		}
    
    	}

[https_github.com_MisterChegy_hibernate]: https://github.com/MisterChegy/hibernate