一 常用方法
save
update
delete
get/load(查询单个记录)
二 测试代码
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.util.Date;
import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
//测试类
public class StudentsTest {
private SessionFactory sessionFactory;
private Session session;
private Transaction transaction;
@Before
public void init(){
// 创建配置对象
Configuration config = new Configuration().configure();
//config.addClass(Students.class);
// 创建服务注册对象
ServiceRegistry serviceRegistery = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
// 创建会话工厂对象
sessionFactory = config.buildSessionFactory(serviceRegistery);
// 创建会话对象
session = sessionFactory.openSession();
// 开启事务
transaction = session.beginTransaction();
}
@After
public void destory(){
// 提交事务
transaction.commit();
// 关闭会话
session.close();
// 关闭会话工厂
sessionFactory.close();
}
@Test
public void testSaveStudents(){
//Students s= new Students(1,"张三丰","男",new Date(),"武当山");
Students s= new Students();
s.setSname("张三丰");
s.setGender("男");
s.setBirthday(new Date());
//s.setAddress("武当山");
Address address = new Address("7232","125674323","湖北");
s.setAddress(address);
session.save(s);
}
@Test
public void testGetStudents()
{
Students s =(Students)session.get(Students.class,1);
System.out.println(s);
}
@Test
public void testLoadStudents()
{
Students s =(Students)session.load(Students.class,1);
System.out.println(s);
}
@Test
public void testUpdateStudents()
{
Students s =(Students)session.load(Students.class,1);
s.setGender("女");
session.update(s);
}
@Test
public void testDeleteStudents()
{
Students s =(Students)session.load(Students.class,1);
session.delete(s);
}
}
三 测试结果
1 get方法测试结果如下
Students [sid=1, sname=张三丰, gender=男, birthday=2017-10-02 09:36:35.0, address=Address@76fe8d1b]
2 load方法测试结果如下
Students [sid=1, sname=张三丰, gender=男, birthday=2017-10-02 09:36:35.0, address=Address@59e9c94]
3 update方法测试结果如下
4 delete方法测试结果如下
四 get与load的区别
1 测试1：是否立即发出SQL语句
1.1 测试代码：
@Test
public void testGetStudents()
{
Students s =(Students)session.get(Students.class,1);
//System.out.println(s);
}
@Test
public void testLoadStudents()
{
Students s =(Students)session.load(Students.class,1);
//System.out.println(s);
}
1.2 测试结果：
testGetStudents会在调试窗口输出下面语句
Hibernate:
select
students0_.SID as SID1_0_0_,
students0_.SNAME as SNAME2_0_0_,
students0_.GENDER as GENDER3_0_0_,
students0_.BIRTHDAY as BIRTHDAY4_0_0_,
students0_.PICTURE as PICTURE5_0_0_,
students0_.POSTCODE as POSTCODE6_0_0_,
students0_.PHOTO as PHOTO7_0_0_,
students0_.ADDRESS as ADDRESS8_0_0_
from
STUDENTS students0_
where
students0_.SID=?
testLoadStudents不会在调试窗口输出结果
1.3 测试说明：
testLoadStudents只有在用的时候才发出SQL语句，是一种懒加载。
2 测试2：get返回对象本身，load返回代理对象
2.1 测试代码：
@Test
public void testGetStudents()
{
Students s =(Students)session.get(Students.class,1);
System.out.println(s.getClass().getName());
//System.out.println(s);
}
@Test
public void testLoadStudents()
{
Students s =(Students)session.load(Students.class,1);
System.out.println(s.getClass().getName());
//System.out.println(s);
}
2.2 测试结果：
get返回结果：
Students
load返回结果：
Students_$$_javassist_0
3 测试3：查询结果为空时区别
3.1 测试代码：
@Test
public void testGetStudents()
{
Students s =(Students)session.get(Students.class,100);
//System.out.println(s.getClass().getName());
System.out.println(s);
}
@Test
public void testLoadStudents()
{
Students s =(Students)session.load(Students.class,100);
//System.out.println(s.getClass().getName());
System.out.println(s);
}
3.2 测试结果：
get测试结果：
null
load测试结果：
抛出异常