Hibernate 数据库操作实例
参考博客：http://blog.csdn.net/fxdaniel/article/details/42420779
Hibernate 数据库操作示例
版本信息
Hibernate版本 4.3.11
Tomcat 8.0
JDK 1.8
Eclipse版本 Neon.1a Release (4.6.1)
Eclipse插件JBoss Tools 4.4.1
数据库 MySQL数据库部分，自己新建一个数据库，我这里建的sh2，自己不用建表。
C:\Users\Peng>mysql -uroot -proot
mysql> create database sh2;
Jar 包使用
lib\required目录下的包就行，此外还需要一个数据库连接的包。需要包的直接下源码。
导入Junit 直接在项目的 Java Bulid Path 中 Add Library找到Junit
源码下载
hibernate-release-4.3.11.Final\lib\required源码
首先是创建 hibernate.cfg.xml,配置Hibernate数据库的配置信息，然后创建POJO类（JavaBean持久化对象）,然后创建对应的对象-关系映射文件（安装了JBOSS 可以自动创建），XXX.hbm.xml,然后创建Hibernate数据库连接的工具类HibernateUtil.java,随后就是dao层，dao.impl层，最后在junit.test包中写测试类。
下面的代码按照包分类
src目录
hibernate.cfg.xml
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driverproperty>
<property name="hibernate.connection.password">rootproperty>
<property name="hibernate.connection.url">jdbc:mysql://127.0.0.1:3306/sh2?useUnicod=true&characterEncoding=utf8property>
<property name="hibernate.connection.username">rootproperty>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialectproperty>
<property name="show_sql">trueproperty>
<property name="format_sql">trueproperty>
<property name="hbm2ddl.auto">updateproperty>
<mapping resource="jxust/model/User.hbm.xml"/>
session-factory>
hibernate-configuration>
jxust.model 包
User.java
package jxust.model;
public class User {
private int id;// 持久化类的标识属性，映射到数据表中的主键列
private String name;
private String password;
private String type;
//getter and setter
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", password=" + password + ", type=" + type + "]";
}
}User.hbm.xml
<hibernate-mapping>
<class name="jxust.model.User" table="USER" lazy="false">
<id name="id" type="int">
<column name="ID" />
<generator class="native" />
id>
<property name="name" type="java.lang.String">
<column name="NAME" length="20"/>
property>
<property name="password" type="java.lang.String">
<column name="PASSWORD" length="12"/>
property>
<property name="type" type="java.lang.String">
<column name="TYPE" length="6"/>
property>
class>
hibernate-mapping>
HibernateUtil.java
package jxust.model;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static SessionFactory sessionFactory;
// 创建线程局部变量threadLocal，用来保存Hibernate的Session
private static final ThreadLocal threadLocal = new ThreadLocal();
// 使用静态代码块初始化Hibernate
static {
try {
// 读取配置文件
Configuration cfg = new Configuration().configure();
// 创建服务注册对象
StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(cfg.getProperties()).build();
// 创建会话工厂对象SessionFactory
sessionFactory = cfg.buildSessionFactory(serviceRegistry);
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
// 获得SessionFactory的实例
public static SessionFactory getsSessionFactory() {
return sessionFactory;
}
// 获得ThreadLocal对象管理的Session
public static Session getsSession() throws HibernateException {
Session session = (Session) threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
// 通过SessionFactory对象创建Session对象
session = (sessionFactory != null) ? sessionFactory.openSession() : null;
// 将Session对象保存到线程局部变量threadLocal中
threadLocal.set(session);
}
return session;
}
// 关闭Session实例
public static void closeSession() {
// 从线程局部变量threadLocal中获取之前存入的Session实例
Session session = (Session) threadLocal.get();
threadLocal.set(null);
if (session != null) {
session.close();
}
}
// 重建SessionFactory
public static void rebuildSessionFactory() {
Configuration configuration = new Configuration();
configuration.configure("/hibernate.cfg.xml");
StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties()).build();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
}
// 关闭缓存和连接池
public static void shutdown() {
getsSessionFactory().close();
}
} jxust.dao 包
UserDAO.java
package jxust.dao;
import java.util.List;
import jxust.model.User;
public interface UserDAO {
public void save(User user);
public User findByIdGet(int id);
public User findByIdLoad(int id);
public List findByHQL(String hql);
public void delete(User user);
public void update(User user);
}
jxust.dao.impl
UserDaoImpl.java
package jxust.dao.impl;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.Transaction;
import jxust.dao.UserDAO;
import jxust.model.HibernateUtil;
import jxust.model.User;
public class UserDaoImpl implements UserDAO {
// 添加用户，需要事务管理
@Override
public void save(User user) {
// 创建Session实例
Session session = HibernateUtil.getsSession();
// 创建Transaction实例
Transaction tx = session.beginTransaction();
try {
// 使用Session的save方法将持久化对象保存到数据库
session.save(user);
// 提交事务
tx.commit();
} catch (Exception e) {
e.printStackTrace();
// 出现异常，回滚事务
tx.rollback();
} finally {
// 关闭Session连接
HibernateUtil.closeSession();
}
}
// 根据id查找用户 ,可以不需要事务管理 Get方式
@Override
public User findByIdGet(int id) {
User user = null;
Session session = HibernateUtil.getsSession();
// 使用session的get方法获取指定id的用户
user = (User) session.get(User.class, id);
if (user == null || "".equals(user)) {
System.out.println("查询id为：" + id + "无结果....");
}
session.close();
return user;
}
// 根据id查找用户 ,可以不需要事务管理 Load方式
@Override
public User findByIdLoad(int id) {
User user = null;
Session session = HibernateUtil.getsSession();
// 使用session的方法获取指定id的用户
user = (User) session.load(User.class, id);
if (user == null || "".equals(user)) {
System.out.println("查询id为：" + id + "无结果....");
}
session.close();
return user;
}
// 根据HQl语句查询
@Override
public List findByHQL(String hql) {
List list = new ArrayList<>();
Session session = HibernateUtil.getsSession();
list = session.createQuery(hql).list();
session.close();
return list;
}
// 删除用户 ,需要事务管理
@Override
public void delete(User user) {
Session session = HibernateUtil.getsSession();
Transaction tx = session.beginTransaction();
try {
session.delete(user);
tx.commit();
} catch (Exception e) {
e.printStackTrace();
tx.rollback();
} finally {
HibernateUtil.closeSession();
}
}
// 修改用户
@Override
public void update(User user) {
Session session = HibernateUtil.getsSession();
Transaction tx = session.beginTransaction();
try {
session.update(user);
tx.commit();
} catch (Exception e) {
e.printStackTrace();
tx.rollback();
} finally {
HibernateUtil.closeSession();
}
}
} junit.test
UserDaoTest.java
package junit.test;
import java.util.List;
import org.junit.Test;
import jxust.dao.impl.UserDaoImpl;
import jxust.model.User;
public class UserDaoTest {
@Test
public void testsave() {
UserDaoImpl udi = new UserDaoImpl();
User user = new User();
user.setId(12);// 主键设置为native 自增，这里设置无效
user.setName("夜阑1");
user.setPassword("yeye");
user.setType("admin");
udi.save(user);
}
@Test
public void testfindByIdGet() {
UserDaoImpl udi = new UserDaoImpl();
User user = udi.findByIdGet(1);
System.out.println(user.toString());
}
@Test
public void testfindByIdLoad() {
UserDaoImpl udi = new UserDaoImpl();
User user = udi.findByIdLoad(2);
System.out.println(user.toString());
// 必须在User.hbm.xml文件的class中设置lazy="false",不使用代理对象，否则有异常
}
@Test
public void testfindByHQL() {
List list = null;
UserDaoImpl udi = new UserDaoImpl();
/**
* 关键字最好大写，这里为了方便
* 因为返回的要是User对象集合，查询内容要相对应
*/
// 1 String hql="FROM User";
// 2 String hql="from User where type='admin'";
String hql = "from User where name like '%夜%'";
list = udi.findByHQL(hql);
for (User s : list) {
System.out.println(s.toString());
}
}
@Test
public void testdelete() {
UserDaoImpl udi = new UserDaoImpl();
User user = new User();
user.setId(5);// 根据主键删除，必须设置
/**
* 如果主键设置了，其他键也设置
* 其他键的数据要与数据库相同 否则不能删除成功，发生异常
*/
user.setName("夜阑2");// 数据库中id为5的name值为夜阑1，有异常，删除不成功
// user.setPassword("yeye234");
udi.delete(user);
}
@Test
public void testupdate() {
UserDaoImpl udi = new UserDaoImpl();
User user = new User();
user.setId(6);// 主键必须设置，修改id为6的项
user.setName("我不是夜阑1");// 其他属性未设置则为空
udi.update(user);
}
}
测试添加的数据
我一开始通过testsave方法添加的4条数据
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 4 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)测试删除数据
删除时session.delete(User user)
根据 user 对象的id值删除数据，（因为主键是唯一标识，候选码不知道可不可以）
如果设置其他属性如
user.setName("夜阑2");(数据库信息为夜阑1，所以不能删除成功)
如果和数据库的信息匹配则可以删除成功，否则不能删除成功
下面是删除过后，再次添加数据，id自增变为了5
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 5 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)测试更新
user.setId(6);// 主键必须设置，修改id为6的项
user.setName("我不是夜阑1");// 其他属性未设置则为空
udi.update(user);没有指定修改的PASSWORD 和TYPE属性，则为null
mysql> select* from user;
+----+-------------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+-------------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 我不是夜阑1 | NULL | NULL |
+----+-------------+----------+-------+
4 rows in set (0.05 sec)更多Hibernate查询，HQL语句查看：http://blog.csdn.net/peng_hong_fu/article/details/53229170
执行测试时，控制台输出的一些代码和异常
控制台Hibernate输出语句.txt
保存数据
Hibernate:
insert
into
USER
(NAME, PASSWORD, TYPE)
values
(?, ?, ?)
********************************
根据id查询get方式
Hibernate:
select
user0_.ID as ID1_0_0_,
user0_.NAME as NAME2_0_0_,
user0_.PASSWORD as PASSWORD3_0_0_,
user0_.TYPE as TYPE4_0_0_
from
USER user0_
where
user0_.ID=?
查询没有的id，出现NullPointerException
java.lang.NullPointerException
********************************
根据id查询load方式
Hibernate:
select
user0_.ID as ID1_0_0_,
user0_.NAME as NAME2_0_0_,
user0_.PASSWORD as PASSWORD3_0_0_,
user0_.TYPE as TYPE4_0_0_
from
USER user0_
where
user0_.ID=?
没有设置 lazy="false",会出现以下异常
java.lang.ClassCastException: jxust.model.User_$$_javassist_0 cannot be cast to javassist.util.proxy.Proxy
查询没有的id,出现ObjectNotFoundException
org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [jxust.model.User#7]
********************************
HQL方式查询所有 "from User"
Hibernate:
select
user0_.ID as ID1_0_,
user0_.NAME as NAME2_0_,
user0_.PASSWORD as PASSWORD3_0_,
user0_.TYPE as TYPE4_0_
from
USER user0_
HQL方式 模糊查询"from User where name like '%夜%'"
Hibernate:
select
user0_.ID as ID1_0_,
user0_.NAME as NAME2_0_,
user0_.PASSWORD as PASSWORD3_0_,
user0_.TYPE as TYPE4_0_
from
USER user0_
where
user0_.NAME like '%夜%'
********************************
删除
Hibernate:
delete
from
USER
where
ID=?
单独主键外的值，删除无效
如果主键设置了，其他键也设置
其他键的数据要与数据库相同
否则发生异常
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
********************************
更新数据
Hibernate:
update
USER
set
NAME=?,
PASSWORD=?,
TYPE=?
where
ID=?
******************************** cmd端，记录的信息
C:\Users\Peng>mysql -uroot -proot
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 160
Server version: 5.7.12-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> user sh2;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user sh2' at line 1
mysql> use sh2;
Database changed
mysql> show tables;
Empty set (0.00 sec)
mysql> show tables;
+---------------+
| Tables_in_sh2 |
+---------------+
| user |
+---------------+
1 row in set (0.00 sec)
mysql> select* from user;
+----+--------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+--------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
+----+--------+----------+-------+
1 row in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
+----+----------+----------+-------+
2 rows in set (0.06 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
+----+----------+----------+-------+
3 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 4 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 4 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 4 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
+----+----------+----------+-------+
3 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 5 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
+----+----------+----------+-------+
3 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+----------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+----------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 夜阑1 | yeye | admin |
+----+----------+----------+-------+
4 rows in set (0.00 sec)
mysql> select* from user;
+----+-------------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+-------------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 我不是夜阑1 | NULL | NULL |
+----+-------------+----------+-------+
4 rows in set (0.05 sec)
mysql> select* from user;
+----+-------------+----------+-------+
| ID | NAME | PASSWORD | TYPE |
+----+-------------+----------+-------+
| 1 | 陈奕迅 | chenchen | admin |
| 2 | 风平浪静 | pingping | admin |
| 3 | 夜阑 | yeye | admin |
| 6 | 我不是夜阑1 | NULL | NULL |
+----+-------------+----------+-------+
4 rows in set (0.00 sec)
mysql> desc user;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| NAME | varchar(20) | YES | | NULL | |
| PASSWORD | varchar(12) | YES | | NULL | |
| TYPE | varchar(6) | YES | | NULL | |
+----------+-------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)
mysql>源码下载
http://download.csdn.net/detail/peng_hong_fu/9687346