Spring MVC事务配置

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，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。

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