3.2 测试

待我称王封你为后i 2022-05-31 23:05 155阅读 0赞

第一步：添加必要的hibernate jar包

第二步：添加数据库驱动

第三步：

项目完整目录结构

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代码：

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
    <!DOCTYPE hibernate-configuration PUBLIC
           "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
     
    <hibernate-configuration>
    
    	<session-factory>
    		
    		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    		<property name="connection.url">jdbc:mysql://localhost:3306/hibernate?characterEncoding=UTF-8</property>
    		<property name="connection.username">root</property>
    		<property name="connection.password">admin</property>
    		
    		<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    		<property name="current_session_context_class">thread</property>
    		<property name="format_sql">true</property>
    		<property name="show_sql">true</property>
    		<property name="hbm2ddl.auto">update</property>
    		
    		
    		<property name="connection.isolation">2</property>
    		
    		<mapping resource="com/hibernate/News.hbm.xml" />
    	</session-factory>
    
    </hibernate-configuration>

持久化类News.java

package com.hibernate;
    
    import java.util.Date;
    
    public class News {
    
    	private Integer id;
    	private String title;
    	private String author;
    	private Date date;
    	public Integer getId() {
    		return id;
    	}
    	public void setId(Integer id) {
    		this.id = id;
    	}
    	public String getTitle() {
    		return title;
    	}
    	public void setTitle(String title) {
    		this.title = title;
    	}
    	public String getAuthor() {
    		return author;
    	}
    	public void setAuthor(String author) {
    		this.author = author;
    	}
    	public Date getDate() {
    		return date;
    	}
    	public void setDate(Date date) {
    		this.date = date;
    	}
    	public News(String title, String author, Date date) {
    		super();
    		this.title = title;
    		this.author = author;
    		this.date = date;
    	}
    	public News() {}
    	@Override
    	public String toString() {
    		return "News [id=" + id + ", title=" + title + ", author=" + author + ", date=" + date + "]";
    	}
    }

News.hbm.xml

<?xml version="1.0"?>
    <!DOCTYPE hibernate-mapping PUBLIC
            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
     
    <hibernate-mapping package="com.hibernate">
        <class name="News" table="news2">
            <id name="id" column="id">
                <generator class="native"></generator>
            </id>
         		<property name="title"></property>
         		<property name="author"></property>
         		<property name="date"></property>
        </class>
         
    </hibernate-mapping>

测试类HibernateTest.java

测试的方法有：

session缓存

flush测试

refresh测试

save测试

clear测试

package com.hibernate;
    
    import java.util.Date;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.Transaction;
    import org.hibernate.cfg.Configuration;
    import org.hibernate.mapping.Set;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    
    import com.hibernate.News;
     
    public class HibernateTest {
    	private SessionFactory sessionfactory;
    	private Session session;
    	private Transaction transaction;
     
    	/**先使用以下代码看能否正常运行，然后再测试各种方法
    	public static void main(String[] args) {
        	
            SessionFactory sf = new Configuration().configure().buildSessionFactory();//获取SessionFactory
     
            Session s = sf.openSession();//通过SessionFactory 获取一个Session
            s.beginTransaction();//在Session基础上开启一个事务
     
            News p = new News();
            p.setAuthor("yiguang");
            p.setTitle("tianshilikai");
            p.setDate(null);
            s.save(p);//通过调用Session的save方法把对象保存到数据库
             
            s.getTransaction().commit();//提交事务
            s.close();//关闭Session
            sf.close();//关闭SessionFactory
        	
        	}
       **/
    	
    	@Before
    	public void init() {
    		 sessionfactory=new Configuration().configure().buildSessionFactory();
    		 session= sessionfactory.openSession();//通过SessionFactory 获取一个Session
    		 transaction=session.beginTransaction();
    		
    	}
    	
    	@After
    	public void destroy() {
    		transaction.commit();
    		session.close();
    		sessionfactory.close();
    		
    	}
    
    	//测试clear
    	/*
    	 * clear():清理缓存
    	 */
    	@Test
    	public void testClear() {
    		News news5=(News) session.get(News.class,1);
    		System.out.println(news5);
    		
    		session.clear();
    		
    		News news6=(News) session.get(News.class,1);
    		System.out.println(news6);
    	}
    	
    	//测试refresh 
    	/*
    	 * refresh():会强制发送select语句，以使session缓存中对象的状态和数据表中的数据保持一致。
    	 */
    	@Test
    	public void refresh() {
    		News news4=(News) session.get(News.class, 1);
    		System.out.println(news4);
    		
    		session.refresh(news4);//修改Author
    		System.out.println(news4);
    	}
    	
    	//测试flush
    	/**
    	 * flush:使数据表中的记录和Session缓存中的对象的状态保持一致，为了保持一致，则可能会发送对应的sql语句。
    		1.在Transaction的commit（）方法中：先调用session的flush方法，再提交事务
    		2.flush（）方法可能会发送SQL语句，但不会提交事务。
    		3.注意：在未提交事务或显示的调用session.flush()方法之前，也有可能会进行flush（）操作。
    			1.执行HQL或QBC查询，会先进行flushz()操作，以得到数据包的最新记录。因为save方法后，必须保证对象的id是存在的。
    
    	 */
    	@Test
    	public void testSessionFlush() {
    		News news=(News) session.get(News.class, 1);
    		System.out.println(news);
    		
    		news.setAuthor("oracle");//开始Author为mysql
    		session.flush();
    		System.out.println(news);
    	}
    	
    	@Test
    	public void testSessionFlush2() {
    		News news3=new News("fanren1","wangyu", new Date());
    		session.save(news3);
    	}
    	
    	//session缓存测试
    	@Test
    	public void testSessionCache() {
    		//两条sql语句，但是只向数据库发送一条请求
    		News news=(News) session.get(News.class, 1);
    		System.out.println(news);
    		
    		News news2=(News) session.get(News.class, 1);
    		System.out.println(news2);
    		
        }
    	
    	//添加一条数据
    	@Test
    	public void testInsert() {
    		News news1=new News("fanren2","wangyu",new Date());
    		session.save(news1);
    	}
     	
        	
    }

先测试testInsert方法，控制台会显示：

Hibernate: 
        insert 
        into
            news2
            (title, author, date) 
        values
            (?, ?, ?)

对应数据库显示：

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[Center]: /images/20220601/c1329dea32794e42b131e3666d394bc7.png
[Center 1]: /images/20220601/e612281497ae4b79a71fe6c7c0be2c08.png