spring之整合Hibernate
spring整合Hibernate整合什么?
1.让IOC容器来管理Hibernate的SessionFactory。
2.让Hibernate使用上spring的声明式事务。
整合步骤:
1.加入Hibernate。
2.加入spring。
3.整合。
一、加入Hibernate
1.加入相应jar包
加入Hibernate所需的依赖包:
将以上包加入到build path。
加入连接数据库所需的依赖包:
将以上包加入到build path。
2.添加Hibernate配置文件: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> <!-- 配置Hibernate的 基本属性--> <!-- 1.数据源需配置到IOC容器中,此处不再需要配置数据源 --> <!-- 2.关联的.hbm.xml也在IOC容器配置SessionFactory实例时再进行配置 --> <!-- 3.配置Hibernate的基本属性:方言、SQL显示及格式化,生成数据表的策略以及二级缓存等 --> <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property> <property name="hibernate.show_sql">true</property> <property name="hibernate.format_sql">true</property> <property name="hibernate.hbm2ddl.auto">update</property> <!-- 配置二级缓存相关的属性 --> </session-factory> </hibernate-configuration>
3.添加实体类以及其hbm配置文件
Account.java
package com.gong.spring.hibernate.entities; public class Account { private Integer id; private String username; private int balance; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public int getBalance() { return balance; } public void setBalance(int balance) { this.balance = balance; } }
Book.java
package com.gong.spring.hibernate.entities; public class Book { private Integer id; private String bookName; private String isbn; private int price; private int stock; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getBookName() { return bookName; } public void setBookName(String bookName) { this.bookName = bookName; } public String getIsbn() { return isbn; } public void setIsbn(String isbn) { this.isbn = isbn; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } public int getStock() { return stock; } public void setStock(int stock) { this.stock = stock; } }
Account.hbm.xml
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated 2020-1-9 11:56:28 by Hibernate Tools 3.5.0.Final --> <hibernate-mapping> <class name="com.gong.spring.hibernate.entities.Account" table="SH_ACCOUNT"> <id name="id" type="java.lang.Integer"> <column name="ID" /> <generator class="native" /> </id> <property name="username" type="java.lang.String"> <column name="USERNAME" /> </property> <property name="balance" type="int"> <column name="BALANCE" /> </property> </class> </hibernate-mapping>
Book.hbm.xml
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated 2020-1-9 11:56:28 by Hibernate Tools 3.5.0.Final --> <hibernate-mapping> <class name="com.gong.spring.hibernate.entities.Book" table="SH_BOOK"> <id name="id" type="java.lang.Integer"> <column name="ID" /> <generator class="native" /> </id> <property name="bookName" type="java.lang.String"> <column name="BOOKNAME" /> </property> <property name="isbn" type="java.lang.String"> <column name="ISBN" /> </property> <property name="price" type="int"> <column name="PRICE" /> </property> <property name="stock" type="int"> <column name="STOCK" /> </property> </class> </hibernate-mapping>
这里需要说明的是table="SH_BOOK"中SH是表的前缀,我们在写hql语句时不用带上,系统会自动识别。
二、加入spring
1.加入相应的jar包
加入spring所需的jar包:
将以上依赖包加入到build path。
2.加入spring配置文件,并进行整合
db.propertites
jdbc.user=root
jdbc.password=123456
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///spring
jdbc.initPoolSize=5
jdbc.maxPoolSize=10
applicationContex.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd 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-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 配置自动扫描的包 --> <context:component-scan base-package="com.gong.spring.hibernate"></context:component-scan> <!-- 配置数据源 --> <!-- 导入资源文件 --> <context:property-placeholder location="classpath:db.properties"/> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="user" value="${jdbc.user}"></property> <property name="password" value="${jdbc.password}"></property> <property name="driverClass" value="${jdbc.driverClass}"></property> <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property> <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property> <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property> </bean> <!-- 配置 Hibernate 的 SessionFactory 实例: 通过 Spring 提供的 LocalSessionFactoryBean 进行配置 --> <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> <!-- 配置数据源属性 --> <property name="dataSource" ref="dataSource"></property> <!-- 配置 hibernate 配置文件的位置及名称 --> <property name="configLocation" value="classpath:hibernate.cfg.xml"></property> <!-- 使用 hibernateProperties 属相来配置 Hibernate 原生的属性 --> <!-- <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">true</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> </props> </property> --> <!-- 配置 hibernate 映射文件的位置及名称, 可以使用通配符 --> <property name="mappingLocations" value="classpath:com/gong/spring/hibernate/entities/*.hbm.xml"></property> </bean> <!-- 配置 Spring 的声明式事务 --> <!-- 1. 配置事务管理器 --> <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"></property> </bean> <!-- 2. 配置事务属性, 需要事务管理器 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="get*" read-only="true"/> <tx:method name="purchase" propagation="REQUIRES_NEW"/> <tx:method name="*"/> </tx:attributes> </tx:advice> <!-- 3. 配置事务切点, 并把切点和事务属性关联起来 --> <aop:config> <aop:pointcut expression="execution(* com.gong.spring.hibernate.service.*.*(..))" id="txPointcut"/> <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/> </aop:config> </beans>
需要注意:假设用的是navicat操作Mysql数据库,对于所连接的数据库,先不要打开,否则不会生成相应的数据表。同时,有两种方式配置hibernate的配置文件,一种是引用外部配置,一种是直接在applicaitonContext.xml文件中进行配置。
最后我们在com.gong.spring.hibernate.test中新建一个SpringHibernateTest.java进行测试:
package com.gong.spring.hibernate.test; import java.sql.SQLException; import java.util.Arrays; import javax.sql.DataSource; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class SpringHibernateTest { private ApplicationContext ctx = null; { ctx = new ClassPathXmlApplicationContext("applicationContext.xml"); } @Test public void testDataSource() throws SQLException { DataSource dataSource = ctx.getBean(DataSource.class); System.out.println(dataSource.getConnection()); } }
执行testDataSource方法,在数据库hb中会生成两个实体类的表:
3.进行代码测试
现在的目录结构如下:
使用基于注解的方式来配置bean,需要先在applicationContext.xml中加入:
<!-- 配置自动扫描的包 --> <context:component-scan base-package="com.gong.spring.hibernate"></context:component-scan>
BookShopDao.java
package com.gong.spring.hibernate.dao; public interface BookShopDao { //根据书号获取书的单价 public int findBookPriceByIsbn(String isbn); //更新书的库存,使书号对应的库存-1 public void updateBookStock(String isbn); //更新账户余额:使username的balance-price public void updateUserAccount(String username, int price); }
BookShopDaoImpl.java
package com.gong.spring.hibernate.dao.impl; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository; import com.gong.spring.hibernate.dao.BookShopDao; import com.gong.spring.hibernate.exceptions.BookStockException; import com.gong.spring.hibernate.exceptions.UserAccountException; @Repository public class BookShopDaoImpl implements BookShopDao { @Autowired private SessionFactory sessionFactory; //获取当前绑定的session private Session getSession() { return sessionFactory.getCurrentSession(); } @Override public int findBookPriceByIsbn(String isbn) { String hql = "SELECT b.price FROM Book b WHERE b.isbn = ?"; Query query = getSession().createQuery(hql).setString(0, isbn); return (Integer) query.uniqueResult(); } @Override public void updateBookStock(String isbn) { //验证书的库存是否充足 String hql2 = "SELECT b.stock FROM Book b WHERE b.isbn = ?"; //检查书的库存是否足够,如果不够,就抛出异常 int stock = (int) getSession().createQuery(hql2).setString(0, isbn).uniqueResult(); if(stock == 0){ throw new BookStockException("库存不足!"); } String hql = "UPDATE Book b set b.stock = b.stock-1 WHERE b.isbn = ?"; getSession().createQuery(hql).setString(0, isbn).executeUpdate(); } @Override public void updateUserAccount(String username, int price) { String hql2 = "SELECT a.balance FROM Account a WHERE a.username = ?"; int balance = (int) getSession().createQuery(hql2).setString(0, username).uniqueResult(); if(balance < price){ throw new UserAccountException("余额不足!"); } String hql = "UPDATE Account a SET a.balance = a.balance - ? WHERE a.username = ?"; getSession().createQuery(hql).setInteger(0, price).setString(1, username).executeUpdate(); } }
这里值得一提的是,hql语句和sql语句是有区别的,会将数据表当作对象来看,因此数据表的首字母要大写。
BookShopException.java和UserAccountException.java是我们自己定义的异常。
BookShopException.java
package com.gong.spring.hibernate.exceptions; public class BookStockException extends RuntimeException{ /** * */ private static final long serialVersionUID = 1L; public BookStockException() { super(); // TODO Auto-generated constructor stub } public BookStockException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) { super(message, cause, enableSuppression, writableStackTrace); // TODO Auto-generated constructor stub } public BookStockException(String message, Throwable cause) { super(message, cause); // TODO Auto-generated constructor stub } public BookStockException(String message) { super(message); // TODO Auto-generated constructor stub } public BookStockException(Throwable cause) { super(cause); // TODO Auto-generated constructor stub } }
UserAccountException.java
package com.gong.spring.hibernate.exceptions; public class UserAccountException extends RuntimeException{ /** * */ private static final long serialVersionUID = 1L; public UserAccountException() { super(); // TODO Auto-generated constructor stub } public UserAccountException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) { super(message, cause, enableSuppression, writableStackTrace); // TODO Auto-generated constructor stub } public UserAccountException(String message, Throwable cause) { super(message, cause); // TODO Auto-generated constructor stub } public UserAccountException(String message) { super(message); // TODO Auto-generated constructor stub } public UserAccountException(Throwable cause) { super(cause); // TODO Auto-generated constructor stub } }
其实就是为异常取了个名字,然后改为自己想要输出的错误信息。
BookShopService.java(用于测试买单本书时候的事务)
package com.gong.spring.hibernate.service; public interface BookShopService { public void purchase(String username, String isbn); }
Cashier.java(用于测试买多本书时候的事务)
package com.gong.spring.hibernate.service; import java.util.List; public interface Cashier { public void checkout(String username, List<String> isbns); }
BookShopServiceImpl.java
package com.gong.spring.hibernate.service.impl; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.gong.spring.hibernate.dao.BookShopDao; import com.gong.spring.hibernate.service.BookShopService; @Service public class BookShopServiceImpl implements BookShopService { @Autowired private BookShopDao bookShopDao; public void purchase(String username, String isbn) { //1. 获取书的单价 int price = bookShopDao.findBookPriceByIsbn(isbn); //2. 更新库存 bookShopDao.updateBookStock(isbn); //3. 更新余额 bookShopDao.updateUserAccount(username, price); } }
CashierImpl.java
package com.gong.spring.hibernate.service.impl; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Propagation; import org.springframework.transaction.annotation.Transactional; import com.gong.spring.hibernate.service.BookShopService; import com.gong.spring.hibernate.service.Cashier; @Service public class CashierImpl implements Cashier { @Autowired private BookShopService bookShopService; @Override public void checkout(String username, List<String> isbns) { for(String isbn: isbns){ bookShopService.purchase(username, isbn); } } }
最后,我们在SpringHibernateTest.java中进行测试:
package com.gong.spring.hibernate.test; import java.sql.SQLException; import java.util.Arrays; import javax.sql.DataSource; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.gong.spring.hibernate.service.BookShopService; import com.gong.spring.hibernate.service.Cashier; public class SpringHibernateTest { private ApplicationContext ctx = null; private BookShopService bookShopService = null; private Cashier cashier = null; { ctx = new ClassPathXmlApplicationContext("applicationContext.xml"); bookShopService = ctx.getBean(BookShopService.class); cashier = ctx.getBean(Cashier.class); } @Test public void testCashier(){ cashier.checkout("AA", Arrays.asList("1001","1002")); } @Test public void testBookShopService(){ bookShopService.purchase("AA", "1001"); } @Test public void testDataSource() throws SQLException { DataSource dataSource = ctx.getBean(DataSource.class); System.out.println(dataSource.getConnection()); } }
首先我们往数据库中添加如下数据:
先测试 testBookShopService方法,结果如下:成功购买了一本java书。
再执行一次该方法:出现异常,余额不足,结果为:
说明我们的spring+hibernate事务是配置成功。
接下来我们测试事务的传播方式,即testCashier方法,首先我们将数据设置为:
第一次执行后的结果:成功买到两本书:
再执行一次:
只买了第一本书,第二本余额不足,因为我们在配置时指定了<tx:method name="purchase" propagation="REQUIRES_NEW"/>。如果设置 propagation="REQUIRD,那么就会一本都买不成功。具体原因可以参考之前所写的博客。
4.总结
至此,spring整合hibernate就基本完成了。
最后补充一些:
Spring Hibernate事务的流程:
(1)在方法执行之前获取session;
(2)把session和当前线程绑定,这样就可以在Dao中使用SessionFactory的getCurrentSession()来获取session;
(3)开启事务;
(4)若方法正常结束,即没有出现异常,则先提交事务,然后使当前线程绑定的session解除绑定,最后关闭session;
(5)若方法出现异常,则先回滚事务,然后使当前线程绑定的session解除绑定,最后关闭session;