Spring 事务配置
要了解事务配置的所有方法，请看一下《Spring事务配置的5种方法》
本文介绍两种配置方法：
一、 XML，使用tx标签配置拦截器实现事务
一、 Annotation方式
以下所使用环境为Spring4.0.3、Hibernate4.3.5
一、 XML，使用tx标签配置拦截器实现事务
Entity类User.java，持久化类，对应数据库表user
package com.lei.demo.entity;
import javax.persistence.*;
@Entity(name="users")
public class Users {
public Users(){
super();
}
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id")
private Integer id;
@Column(name="user_name",length=32)
private String user_name;
@Column(name="age")
private Integer age;
@Column(name="nice_name",length=32)
private String nice_name;
//属性实现......
}
UserDAO.javar，user的一些操作，其中属性sessionFactory应该由Spring注入，如下：
package com.lei.demo.dao;
import java.util.List;
import javax.annotation.Resource;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;
import com.lei.demo.entity.Users;
public class UsersDAO {
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public SessionFactory getSessionFactory() {
return sessionFactory;
}
public List<Users> getAllUser(){
String hsql="from users";
Session session = sessionFactory.getCurrentSession();
Query query = session.createQuery(hsql);
return query.list();
}
}
UserService.java，业务实现类，如下
package com.lei.demo.service;
import javax.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import com.lei.demo.dao.*;
public class UserService {
private UsersDAO userDao;
public int userCount(){
return userDao.getAllUser().size();
}
public UsersDAO getUserDao() {
return userDao;
}
public void setUserDao(UsersDAO userDao) {
this.userDao = userDao;
}
}
首先看一下xml配置，spring-hibernate.xml如下：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
">
<!-- Hibernate4 -->
<!-- 加载资源文件 其中包含变量信息，必须在Spring配置文件的最前面加载，即第一个加载-->
<context:property-placeholder location="classpath:persistence-mysql.properties" />
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan">
<list>
<!-- 可以加多个包 -->
<value>com.lei.demo.entity</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<!-- <prop key="hibernate.current_session_context_class">thread</prop> -->
</props>
</property>
</bean>
<!-- 数据库映射 -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.pass}" />
</bean>
<!-- 配置Hibernate事务管理器 -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<!-- 配置事务异常封装 -->
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
<!-- 声明式容器事务管理 ,transaction-manager指定事务管理器为transactionManager -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="add*" propagation="REQUIRED" />
<tx:method name="get*" propagation="REQUIRED" />
<tx:method name="*" read-only="true" />
</tx:attributes>
</tx:advice>
<aop:config expose-proxy="true">
<!-- 只对业务逻辑层实施事务 -->
<aop:pointcut id="txPointcut" expression="execution(* com.lei.demo.service..*.*(..))" />
<!-- Advisor定义，切入点和通知分别为txPointcut、txAdvice -->
<aop:advisor pointcut-ref="txPointcut" advice-ref="txAdvice"/>
</aop:config>
</beans>
其中主要配置中是tx:advice和aop:config两个配置节，以Spring AOP的方式实现事务管理。
tx:advice配置了事务的管理者是transactionManager，同时tx:method也规定了如果方法名匹配“add*”和“get*”方法时使用事务，propagation是设定事务的传播级别。除了“add*”和“get*”方法，其他的方法的事务是只读的（典型地，对于只执行查询的事务你会将该属性设为true，如果出现了更新、插入或是删除语句时只读事务就会失败）
aop:config指定了一个aop:pointcut去引用上边的advice。
这样就通过AOP的拦截机制实现了事务，当然你还要用Spring的方式自己配置UserDAO和UserService。
二、 Annotation方式
第一步，首先看一下web.xml，如下：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>Archetype Created Web Application</display-name>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:/spring-*.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>lei-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:/lei-dispatcher-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>lei-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
第二步，spring-hibernate配置，见以下spring-hibernate.xml配置
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
">
<!-- Hibernate4 -->
<!-- 加载资源文件 其中包含变量信息，必须在Spring配置文件的最前面加载，即第一个加载-->
<context:property-placeholder location="classpath:persistence-mysql.properties" />
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan">
<list>
<!-- 可以加多个包 -->
<value>com.lei.demo.entity</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<!-- <prop key="hibernate.current_session_context_class">thread</prop> -->
</props>
</property>
</bean>
<!-- 数据库映射 -->
<!-- class="org.apache.tomcat.dbcp.dbcp.BasicDataSource" -->
<!-- class="org.springframework.jdbc.datasource.DriverManagerDataSource" -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.pass}" />
</bean>
<!-- 配置Hibernate事务管理器 -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<!-- 配置事务异常封装 -->
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
</beans>
第一节中xml配置事务中需要通过配置tx:advice和aop:config来增加事务的功能。此处采用全注释方法，这两个配置节就不需要了。
相应的需要在视图解析配置中启用注释，如下lei-dispatcher-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
">
<!-- 启动自动扫描 该包下所有的Bean(@Controller) -->
<context:component-scan base-package="com.lei.demo" />
<!-- 基于注释的事务，当注释中发现@Transactional时，使用id为“transactionManager”的事务管理器 -->
<!-- 如果没有设置transaction-manager的值，则spring以缺省默认的事务管理器来处理事务，默认事务管理器为第一个加载的事务管理器 -->
<tx:annotation-driven transaction-manager="transactionManager"/>
<!-- 定义视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/user/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
</beans>
UserDAO如下
package com.lei.demo.dao;
import java.util.List;
import javax.annotation.Resource;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;
import com.lei.demo.entity.Users;
@Repository
public class UsersDAO {
@Resource(name="sessionFactory")
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public SessionFactory getSessionFactory() {
return sessionFactory;
}
public List<Users> getAllUser(){
String hsql="from users";
Session session = sessionFactory.getCurrentSession();
Query query = session.createQuery(hsql);
return query.list();
}
}
UserService.java如下
package com.lei.demo.service;
import javax.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import com.lei.demo.dao.*;
@Service("userService")
public class UserService {
@Resource
private UsersDAO userDao;
@Transactional
public int userCount(){
return userDao.getAllUser().size();
}
public UsersDAO getUserDao() {
return userDao;
}
public void setUserDao(UsersDAO userDao) {
this.userDao = userDao;
}
}
这里，方法名userCount上加入@Transactional，说明这个方法要启用事务。如果类名UserService上加入@Transactional，则表明这个类中的所有方法都会启用事务。
如果配有多个transactionManager，例如配置有transactionManager1,和transactionManager2，则可以通过@Transactional(“transactionManager1”)，的方式指定使用哪个数据源的事务。
源代码下载：
http://www.oschina.net/code/snippet_1764868_35775