Spring MVC事务配置

蔚落 2022-08-18 03:04 58阅读 0赞

## 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 ">
    
        
        
        <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>
                    
                    <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>
                     
                </props>
            </property>
        </bean>
    
        
        <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>
    
        
        <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
          <property name="sessionFactory" ref="sessionFactory" />
       </bean>
    
       
       <bean id="persistenceExceptionTranslationPostProcessor" class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
    
       
        <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">
            
            <aop:pointcut id="txPointcut" expression="execution(* com.lei.demo.service..*.*(..))" />
            
            <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 ">
    
        
        
        <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>
                    
                    <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>
                     
                </props>
            </property>
        </bean>
    
        
        
        
        <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>
    
        
        <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
          <property name="sessionFactory" ref="sessionFactory" />
       </bean>
    
       
       <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

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。