關於 SSM 事務配置失效

1.在Mysql中，只有當表的類型是INNODB的時候，才支持事務，因此須要把表的類型設置爲INNODB,不然沒法觀察到事務.

修改表的類型爲INNODB的SQL：

alter table hero ENGINE = innodb;
查看錶的類型的SQL

show table status from tablename;

2.

 applicationContext.xml

<!-- 開啓事務註解，標註@Transactional的類和方法將具備事務性 -->
<tx:annotation-driven transaction-manager="txManager"  proxy-target-class="true" />
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<!--spring的配置文件application.xml中包掃描不須要掃描@Controller註解的， 具體以下：-->
<context:component-scan base-package="com.crossoverJie">
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    <context:exclude-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
</context:component-scan>

3.SpringMVC.xml

<!--springMVC配置文件springMVC-servlet.xml中只須要掃描@Controller註解的，具體以下：-->
<context:component-scan base-package="com.crossoverJie">
    <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    <!--下面這個是防止事務沒起做用，spring.xml的父容器先於Servlet的子容器生效，將Service提早加載了。這裏不用再進行加載裝配-->
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service" />
</context:component-scan>

4.test

在方法上加上註解：

@Transactional(propagation = Propagation.REQUIRED, rollbackFor = Throwable.class)
@Override
public void addTwo() {
        addOne();
    Category c1 = new Category();
    c1.setName("短的名字");
    categoryMapper.add(c1);

}
@Transactional(propagation = Propagation.REQUIRED, rollbackFor = Throwable.class)
@Override
public void addOne() {
    Category c2 = new Category();
    c2.setName("名字長對應字段放不下");
    categoryMapper.add(c2);
    int i = 9 / 0; //這裏會拋出異常
}

執行並查看日誌：

java.lang.NullPointerException //異常信息

DEBUG [main] (AbstractPlatformTransactionManager.java:847) - Initiating transaction rollback //回滾 DEBUG [main] (DataSourceTransactionManager.java:284) - Rolling back JDBC transaction on Connection [com.mysql.jdbc.JDBC4Connection@6ea2bc93] DEBUG [main] (DataSourceTransactionManager.java:327) - Releasing JDBC Connection [com.mysql.jdbc.JDBC4Connection@6ea2bc93] after transaction DEBUG [main] (DataSourceUtils.java:327) - Returning JDBC Connection to DataSource //返回鏈接到鏈接池 說明事務生效了，遇到異常回滾。