ssm框架的事务处理

╰半橙微兮° 2022-06-02 00:58 226阅读 0赞

## 昨天发了一篇关于事务不回滚的文章。问题就是注解扫描的问题。今天就想写一篇事务处理的详细文章。 ##

说到spring的事务处理，不得不先说一下ssm框架主要的两个配置文件 一个是spring的，一个是springmvc的（其实还有一个mybaties的配置文件，但基本和spring的写在一起了）

springmvc的配置文件

<context:component-scan base-package="com.dncps.action" />
        
         <mvc:annotation-driven></mvc:annotation-driven>
    
         <mvc:resources mapping="/js/**" location="/js/"/>
        <mvc:resources mapping="/css/**" location="/css/"/>
        <mvc:resources mapping="/fonts/**" location="/fonts/"/>
        <mvc:resources mapping="/images/**" location="/images/"/>

spring配置文件

<context:component-scan base-package="com.dncps.*" />
        
        <context:property-placeholder location="classpath:resources/db.properties" />
        <context:property-placeholder location="classpath:resources/log4j.properties" />
        
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="${jdbc.driver}"/>
            <property name="jdbcUrl" value="${jdbc.url}"/>
            <property name="user" value="${jdbc.user}"/>
            <property name="password" value="${jdbc.password}"/>
        </bean>
    
        
          <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
                <property name="messageConverters">  
                     <list>  
                        <ref bean="mappingJackson2HttpMessageConverter" />  
                    </list>  
               </property>  
        </bean>  
    
        <bean id="mappingJackson2HttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">  
                 <property name="supportedMediaTypes">  
                     <list>  
                         <value>text/html;charset=UTF-8</value>  
                        <value>text/json;charset=UTF-8</value>  
                         <value>application/json;charset=UTF-8</value>  
                     </list>  
                 </property>  
       </bean>
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            
            <property name="typeAliasesPackage" value="com.dncps.value" />
            
            <property name="mapperLocations" value="classpath:mapper/*Mapper.xml" />
            <property name="dataSource" ref="dataSource" />
        </bean>
        
        <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
            <constructor-arg ref="sqlSessionFactory" />
        </bean>
    
        
        <bean id="transactionManager"
            class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
            <property name="dataSource" ref="dataSource" />
        </bean>
    
        
        <tx:annotation-driven transaction-manager="transactionManager"/>
    
          
    <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">  
        <property name="defaultErrorView">     
            <value>/error/error</value>  
        </property>  
        <property name="defaultStatusCode">     
            <value>500</value>  
        </property>      
    <property name="warnLogCategory">     
            <value>org.springframework.web.servlet.handler.SimpleMappingExceptionResolver</value>  
        </property>      
    </bean>

service层的，在service层控制事务进行回滚要使用`@Transactional`注释的方式其中rollbackfor参数是遇到什么异常触发回滚，Throwable.class就是所有异常，当然仅限这个方法。如果想应用于 整个类，可以把注释在类上面。  
在下面的代码中有一个错误`int yichagn=1/0;` 当遇到异常后因为没有执行carddao.updateuserfromcarddao(user);方法，所以`carddao.updatecard(map2);` 这个方法会回滚  
数据库数据不改变。

@Transactional(rollbackFor = Throwable.class)
        @Override
        public void recharge1(HttpSession session, HttpServletRequest request,
                HttpServletResponse response) throws Exception {
            Map<String, String> map = new HashMap<String, String>();
            Map<Object,Object> map2 = new HashMap<Object,Object>();
            String cardid=request.getParameter("cardid");
            String cardnumber=request.getParameter("cardnumber");
            String code=request.getParameter("code");
            if("".equals(cardid)||"".equals(cardnumber)||"".equals(code)){
    
                        response.getWriter().write("账号、密码、验证码不能为空！");
    
            }else if(code.equals(session.getAttribute("cardsafecode"))){
                map.put("cardid", cardid);
                map.put("cardnumber", cardnumber);
                card getcardByidandnumber = carddao.getcardByidandnumber(map);
                if(getcardByidandnumber !=null){
                    if(getcardByidandnumber.getCardstate()==0){
    
                            response.getWriter().write("对不起，充值失败，此卡尚未出库！");
    
                    }else if(getcardByidandnumber.getCardstate()==1){
                            user attribute = (user) session.getAttribute("user");
                            user user=new user();
                            map2.put("cardstate",2);
                            map2.put("cardid", cardid);
                            Format f = new SimpleDateFormat("yyyy-MM-dd");
                            Calendar c = Calendar.getInstance();
                            c.add(Calendar.MONTH, 6);
                            user.setUserpaytime(f.format(c.getTime()));
                            user.setUserid(Integer.valueOf(attribute.getUserid()));
                            user.setUsertype(1);
                            carddao.updatecard(map2);
                            int yichagn=1/0;//异常
                            carddao.updateuserfromcarddao(user);
    
                            response.getWriter().write("true");
    
                    }else if(getcardByidandnumber.getCardstate()==2){
    
                                response.getWriter().write("充值失败，此卡已经被人充值，若有疑问请联系！！");
    
                    }
                }else{
    
                        response.getWriter().write("无此卡！");
    
                }
            }else{
    
                    response.getWriter().write("验证码错误！");
            }
        }

最后说一下，因为自带的事务处理机制所以要在spring中进行包扫描，而不能认为springmvc中进行扫描过后就不用在spring配置文件中扫描了。