环境与版本
除了上一篇中的hibernate的相关lib 外
Java事务管理之Hibernate
还需要加入Spring的lib 包和如下的一些依赖包
org.aopalliance
org.aspectj
org.apache.commons
Spring 的版本是Spring 4.1.5。
依赖包也可以到Spring 官方网站下载到 ,名字类似 spring-framework-3.0.2.RELEASE-dependencies
理论知识
Spring和Hibernate整合后,通过Hibernate API进行数据库操作时发现每次都要opensession,close,beginTransaction,commit,这些都是重复的工作,我们可以把事务管理部分交给spring框架完成。
使用spring管理事务后在dao中不再需要调用beginTransaction和commit,也不需要调用session.close(),使用API sessionFactory.getCurrentSession()来替代sessionFactory.openSession()
* 如果使用的是本地事务(jdbc事务)
<property name="hibernate.current_session_context_class">thread</property>
* 如果使用的是全局事务(jta事务)
<property name="hibernate.current_session_context_class">jta</property>
Spring中Propagation类的事务属性详解:
PROPAGATION_REQUIRED:支持当前事务,如果当前没有事务,就新建一个事务。这是最常见的选择。
PROPAGATION_SUPPORTS:支持当前事务,如果当前没有事务,就以非事务方式执行。
PROPAGATION_MANDATORY:支持当前事务,如果当前没有事务,就抛出异常。
PROPAGATION_REQUIRES_NEW:新建事务,如果当前存在事务,把当前事务挂起。
PROPAGATION_NOT_SUPPORTED:以非事务方式执行操作,如果当前存在事务,就把当前事务挂起。
PROPAGATION_NEVER:以非事务方式执行,如果当前存在事务,则抛出异常。
PROPAGATION_NESTED:支持当前事务,如果当前事务存在,则执行一个嵌套事务,如果当前没有事务,就新建一个事务。
Spring 可以使用xml方式进行配置或是使用注解声明的方式进行事务的管理。
xml 方式配置事务代码实例
代码结构如下:
applicationContext.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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:util="http://www.springframework.org/schema/util" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <context:component-scan base-package="com.oscar999.trans.sprhib" /> <context:property-placeholder location="classpath:/com/oscar999/trans/sprhib/config.properties" /> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <!-- Connection Info --> <property name="driverClassName" value="${jdbc.driver}" /> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}"></property> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">true</prop> <prop key="hibernate.jdbc.batch_size">20</prop> <prop key="hibernate.enable_lazy_load_no_trans">true</prop> <prop key="hibernate.current_session_context_class">org.springframework.orm.hibernate4.SpringSessionContext</prop> <prop key="jdbc.use_streams_for_binary">true</prop> </props> </property> <property name="packagesToScan"> <list> <value>com.oscar999.trans.sprhib.model</value> </list> </property> </bean> <!-- Transaction --> <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory" /> </bean> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="save*" propagation="REQUIRED" /> <tx:method name="*" read-only="true" /> </tx:attributes> </tx:advice> <aop:config proxy-target-class="true"> <aop:pointcut expression="execution(* com.oscar999.trans.sprhib.dao.ProductDAOImpl.*(..))" id="pointcut" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" /> </aop:config> </beans>
config.properties
jdbc.driver=oracle.jdbc.driver.OracleDriver jdbc.url=jdbc:oracle:thin:@12.6.18.43:1521:orcl jdbc.username= jdbc.password=oracle
Product.java
/** * @Title: Product.java * @Package com.oscar999.trans.hibernate * @Description: * @author XM * @date Feb 15, 2017 1:44:47 PM * @version V1.0 */ package com.oscar999.trans.sprhib.model; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.Table; /** * @author XM * */ @Entity @Table(name = "TEST_PRODUCT") public class Product implements Serializable { public Product() { } @Id @Column(name = "ID") private Integer id; @Column(name = "NAME") private String name; @Column(name = "PRICE") private String price; private static final long serialVersionUID = 1L; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPrice() { return price; } public void setPrice(String price) { this.price = price; } }
ProductDAOImpl.java
/** * @Title: ProductDAOImpl.java * @Package com.oscar999.trans.sprhib * @Description: * @author XM * @date Feb 15, 2017 4:15:09 PM * @version V1.0 */ package com.oscar999.trans.sprhib.dao; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository; import com.oscar999.trans.sprhib.model.Product; /** * @author XM * */ @Repository public class ProductDAOImpl { @Autowired private SessionFactory sessionFactory; public Product findProductById(int id) { Session session = sessionFactory.getCurrentSession(); Product product = (Product) session.get(Product.class, id); return product; } public Product saveProduct(Product product) { Session session = sessionFactory.getCurrentSession(); session.save(product); return product; } }
ProductServiceImpl.java
package com.oscar999.trans.sprhib; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.oscar999.trans.sprhib.dao.ProductDAOImpl; import com.oscar999.trans.sprhib.model.Product; @Service public class ProductServiceImpl { @Autowired private ProductDAOImpl productdao; public void findProduct(int id) { Product product = productdao.findProductById(id); if (product != null) { System.out.println(product.getName()); } } public void saveProduct() { Product product = new Product(); product.setId(2); product.setName("product2"); product.setPrice("price2"); productdao.saveProduct(product); } }
TestMain.java
/** * @Title: TestMain.java * @Package com.oscar999.trans.sprhib * @Description: * @author XM * @date Feb 15, 2017 3:54:54 PM * @version V1.0 */ package com.oscar999.trans.sprhib; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * @author XM * */ public class TestMain { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub ApplicationContext applicationContext = new ClassPathXmlApplicationContext("com/oscar999/trans/sprhib/applicationContext.xml"); ProductServiceImpl productService = applicationContext.getBean(ProductServiceImpl.class); //productService.findProduct(1); productService.saveProduct(); } }
说明如下:
get 可以不需要transaction
插入或是更新如果没有的话, 就不会更新成功
声明方式配置事务
事物注解方式: @Transactional
当标于类前时,标示类中所有方法都进行事物处理,以下代码在service层进行事务处理(给Service层配置事务是比较好的方式,因为一个Service层方法操作可以关联到多个DAO的操作。在Service层执行这些Dao操作,多DAO操作有失败全部回滚,成功则全部提交。)
@Service
@Transactional
public class UserServiceImpl implements UserService {
@Autowired
private UserDao userDao;
public User getUserById(int id) {
return userDao.findUserById(id);
}
}
当类中某些方法不需要事物时:
@Service
@Transactional
public class UserServiceImpl implements UserService {
@Autowired
private UserDao userDao;
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public User getUserById(int id) {
return userDao.findUserById(id);
}
}