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:
以下所使用环境为Spring4.0.3、Hibernate4.3.5
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,表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。
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