一、Hibernate入门案例剖析：

　　 ①创建实体类Student 并重写toString方法

public class Student {    private Integer sid;    private Integer age;    private String name;    public Integer getSid() {        return sid;    }    public void setSid(Integer sid) {        this.sid = sid;    }    public Integer getAge() {        return age;    }    public void setAge(Integer age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    @Override    public String toString() {        return "Student [sid=" + sid + ", age=" + age + ", name=" + name + "]";    }        }

　　② 创建学生对象 并赋值

 

 　③引入jar包

 

④ 构建大配置<hibernate.cfg.xml>

可分为以下步骤：

1.连接数据库的语句

2.sql方言

3.可省的配置(show_sql、format_sql 取值为true)

4.让程序生成底层数据表(hbm2ddl.auto) update/create。create是每次将数据表删除后，重新创建

5.关联小配置

<mapping resource="cn/happy/entity/Student.hbm.xml" />

关键代码如下：

     
         
              
               
               
       
        oracle.jdbc.OracleDriver
               
               
       
        jdbc:oracle:thin:@localhost:1521:orcl3
               
       
        wj
               
       
        9090
               
               
       
        org.hibernate.dialect.Oracle10gDialect
               
               
       
        true
                      
               
               
                
       
        update
                 
               
               
                   
      
     

⑤ 构建小配置(Student.hbm.xml)

     
             
              
                  
                                
                       
         SEQ_NUM            
                
              
               
               
           
      
     

⑥ 工具类HibernateUtil、构建私有静态的Configuration、SessionFactory对象、定义返回session以及关闭session的方法

private static Configuration cf=new Configuration().configure();    private static SessionFactory sf=cf.buildSessionFactory();        //方法返回session    public static Session getSession(){        return sf.openSession();    }        //关闭Session        public static void CloseSession(){        getSession().close();    }复制代码

⑦测试类【增删改查】 使用标记After、Before可简化代码

package cn.happy.test;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.junit.After;import org.junit.Before;import org.junit.Test;import cn.happy.entity.Student;import cn.happy.util.HibernateUtil;public class Test1 {     Session session;    Transaction tx;     @After    public void afterTest(){        tx.commit();        HibernateUtil.CloseSession();    }    @Before    public void initData(){        session=HibernateUtil.getSession();        tx=session.beginTransaction();    }        /*     * get方法查询     */    @Test    public void getData(){        Student stu=(Student)session.get(Student.class, 3);        System.out.println(stu);    }    /*     * 增加     */        @Test    public void addData(){        Student stu=new Student();        stu.setSid(12);        stu.setAge(11);        stu.setName("李小龙1");    //读取大配置文件 获取连接信息        Configuration cfg=new Configuration().configure();        //创建SessionFactory        SessionFactory fa=cfg.buildSessionFactory();    //加工Session    Session se=fa.openSession();    Transaction tx = se.beginTransaction();    //保存    se.save(stu);    //事务提交    tx.commit();    se.close();        System.out.println("Save ok!");    }         /*     * 删除     */    @Test    public void delData(){        Session session=HibernateUtil.getSession();        Student stu=new Student();        stu.setSid(2);        Transaction tx=session.beginTransaction();        session.delete(stu);        tx.commit();        HibernateUtil.CloseSession();        System.out.println("del ok!");    }        /*     * 修改     */    @Test    public void updateData(){        Session session=HibernateUtil.getSession();                Student stu=(Student)session.load(Student.class,3);        stu.setName("呵呵");        Transaction tx=session.beginTransaction();        session.update(stu);        tx.commit();        HibernateUtil.CloseSession();        System.out.println("update ok!");    }    }