在很多场景下，我们不需要使用JdbcTemplate直接操作SQL语句，这时候可以用ORM工具来节省数大量的的代码和开发时间。ORM工具能够把注意力从容易出错的SQL代码转向如何实现应用程序的真正需求。
Spring对ORM框架的支持提供了与这些框架的集成点以及一些附加的服务：
Hibernate是在开发者社区很流行的开源ORM框架。
mysql新建数据库store，然后执行如下sql：
1 create table Category ( 2 Id int not null, 3 Name varchar(80) null, 4 constraint pk_category primary key (Id) 5 ); 6 7 INSERT INTO category(id,Name) VALUES (1,‘女装‘); 8 INSERT INTO category(id,Name) VALUES (2,‘美妆‘); 9 INSERT INTO category(id,Name) VALUES (3,‘书籍‘);
我用的IDE是IdeaIU，通过maven构建项目，通过xml配置spring。完成后的代码结构为：
class Category{
private int cateId;
private String cateName;
//次数省略get,set方法
@Override
public String toString() {
return "id="+cateId+" name="+cateName;
}
}
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.5.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.30</version>
</dependency>
</dependencies>
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/store"></property>
<property name="username" value="root"></property>
<property name="password" value="root"></property>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="configLocation" value="classpath:hibernate/hibernate.cfg.xml"/>
</bean>
<tx:annotation-driven/>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<bean id="categoryDao" class="CategoryDao">
<constructor-arg ref="sessionFactory"></constructor-arg>
</bean>
</beans>
dataSource没什么特别的，就不在解释了。看下其他几点：
①hibernate sessionFactory：
使用Hibernate所需的主要接口是org.hibernate.Session，Session接口提供了CRUD等最基本的数据访问功能。通过Hibernate的Session接口，应用程序的Repository能够满足所有的持久化需求。而获取Hibernate Session对象的标准方式是借助于Hibernate SessionFactory接口的实现类。
在sessionFactory配置主要设置了两个属性：dataSource设置了数据连接，configLocation设置了hibernate配置文件的路径。
②事务
要是数据库操作支持事务，需要配置<tx:annotation-driven/>和transactionManager。
①hibernate.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="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<mapping resource="hibernate/Category.hbm.xml"/>
</session-factory>
</hibernate-configuration>
②Category.hbm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Category" table="Category">
<id name="cateId" column="id">
<generator class="native"/>
</id>
<property name="cateName" column="name"/>
</class>
</hibernate-mapping>
如果方法要支持事务，需要加注解@Transactional。
public class CategoryDao {
private SessionFactory sessionFactory;
public CategoryDao(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
private Session currentSession() {
return sessionFactory.getCurrentSession();
}
@Transactional
public void save(Category category) {
currentSession().save(category);
}
@Transactional
public void update(Category category){
currentSession().update(category);
}
@Transactional
public void delete(int id) {
Query query = currentSession().createSQLQuery("DELETE FROM category WHERE Id=::ID");
query.setInteger("::ID", id);
query.executeUpdate();
}
@Transactional
public int count() {
return getAll().size();
}
@Transactional
public Category getById(int id) {
Criteria criteria=currentSession().createCriteria(Category.class);
criteria.add(Restrictions.eq("id",id));
return (Category) criteria.uniqueResult();
}
@Transactional
public List<Category> getAll() {
return currentSession().createCriteria(Category.class).list();
}
}
@ContextConfiguration(locations = "classpath:applicationContext.xml")
@RunWith(SpringJUnit4ClassRunner.class)
public class testCategoryDao {
@Autowired
private CategoryDao categoryDao;
@Test
public void testAdd() {
Category category = new Category();
category.setCateId(4);
category.setCateName("母婴");
categoryDao.save(category);
}
@Test
public void testUpdate() {
Category category = new Category();
category.setCateId(4);
category.setCateName("男装");
categoryDao.update(category);
}
@Test
public void testGetById() {
int id = 4;
Category category = categoryDao.getById(id);
if(category==null){
System.out.println("not exist");
}else {
System.out.println(category.toString());
}
}
@Test
public void testGetAll() {
List<Category> categories = categoryDao.getAll();
for (Category item : categories) {
System.out.println(item);
}
}
@Test
public void testCount() {
int count = categoryDao.count();
System.out.println(count);
}
@Test
public void testDelete() {
int id = 4;
categoryDao.delete(id);
}
}
源码地址：https://github.com/cathychen00/learnjava/tree/master/DemoHibernate
原文：http://www.cnblogs.com/janes/p/6972440.html