Spring事务管理——回滚(rollback-for)控制

探讨Spring事务控制中，异常触发事务回滚原理。文章进行了6种情况下的Spring事务是否回滚。
以下代码都是基于Spring与Mybatis整合，使用Spring声明式事务配置事务方法。

1.不捕获异常(一般处理方式)

代码，其中contentMappger.updateWithErrTest(31L); 是SQL语句错误，用来测试回滚。

    /**     * 删除多条记录     */    @Override    public ShopResult deleteContentGroup(String[] ids) {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        return ShopResult.ok();    }

运行结果：报错，事务发生了回滚，即由于错误代码，前面的for循环删除记录事务被回滚了。

### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1] with root causecom.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)    at com.mysql.jdbc.Util.getInstance(Util.java:381)    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3536)    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3468)    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1957)    ..................    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)    at com.sun.proxy.$Proxy35.updateWithErrTest(Unknown Source)    at com.shop.manager.service.impl.ContentServiceImpl.deleteContentGroup(ContentServiceImpl.java:94)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:498)    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)    .......

2. 捕获异常，但不处理，不抛出

代码

    /**     * 删除多条记录     */    @Override    public ShopResult deleteContentGroup(String[] ids) {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        try {            contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        } catch (Exception e) {            //捕获异常，但不处理            System.out.println("-----nothing to do-------");        }        return ShopResult.ok();    }

运行结果：事务提交，未回滚。

### The error occurred while setting parameters### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1]-----nothing to do-------2017-06-18 14:27:59,493 [http-bio-8080-exec-4] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization committing SqlSession //(事务提交)[org.apache.ibatis.session.defaults.DefaultSqlSession@616a85a9]

3. 捕获异常，并抛出RuntimeException异常

Spring碰到Unchecked Exceptions都会回滚，不仅是RuntimeException，也包括Error。
代码

    /**     * 删除多条记录     */    @Override    public ShopResult deleteContentGroup(String[] ids) {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        try {            contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        } catch (Exception e) {            System.out.println("----throw Exception-----");            throw new RuntimeException();        }        return ShopResult.ok();    }

运行结果：如预期的一样，抛出RuntimeException，事务发生回滚。

### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1]----throw Exception-----2017-06-18 14:21:27,928 [http-bio-8080-exec-1] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization deregistering SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3ef56e3a]...............2017-06-18 14:21:27,941 [http-bio-8080-exec-1] [org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver]-[DEBUG] Resolving exception from handler [public com.shop.common.pojo.ShopResult com.shop.manager.controller.ContentController.deleteContentGroup(java.lang.String)]: java.lang.RuntimeException2017-06-18 14:21:27,941 [http-bio-8080-exec-1] [org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver]-[DEBUG] Resolving exception from handler [public com.shop.common.pojo.ShopResult com.shop.manager.controller.ContentController.deleteContentGroup(java.lang.String)]: java.lang.RuntimeException2017-06-18 14:21:27,942 [http-bio-8080-exec-1] [org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver]-[DEBUG] Resolving exception from handler [public com.shop.common.pojo.ShopResult com.shop.manager.controller.ContentController.deleteContentGroup(java.lang.String)]: java.lang.RuntimeException2017-06-18 14:21:27,942 [http-bio-8080-exec-1] [org.springframework.web.servlet.DispatcherServlet]-[DEBUG] Could not complete requestjava.lang.RuntimeException    at com.shop.manager.service.impl.ContentServiceImpl.deleteContentGroup(ContentServiceImpl.java:98)  //异常    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

4.捕获异常，并继续抛出原捕获的异常

代码：

    /**     * 删除多条记录     */    @Override    public ShopResult deleteContentGroup(String[] ids) {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        try {            contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        } catch (Exception e) {            //捕获异常，继续抛出            System.out.println("-----throw Exception-------");            throw e;        }        return ShopResult.ok();    }

运行结果：抛出异常，事务发生回滚

### The error occurred while setting parameters### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1]-----throw Exception-------2017-06-18 14:36:25,308 [http-bio-8080-exec-9] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization deregistering SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@45fe0f70]2017-06-18 14:36:25,308 [http-bio-8080-exec-9] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization closing SqlSession //事务回滚[org.apache.ibatis.session.defaults.DefaultSqlSession@45fe0f70]

5. 捕获异常，并抛出新new的异常(或自定义Exception异常) new Exception

代码：

    /**     * 删除多条记录     * @throws Exception      */    @Override    public ShopResult deleteContentGroup(String[] ids) throws Exception {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        try {            contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        } catch (Exception e) {            //捕获异常，抛出新异常            System.out.println("-----throw new Exception(e)-------");            throw new Exception(e);        }               return ShopResult.ok();    }

运行结果：事务提交，未回滚。（Spring的默认回滚异常类型不包括Exception）

### The error occurred while setting parameters### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1]-----throw new Exception(e) -------2017-06-18 14:43:16,098 [http-bio-8080-exec-10] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization committing SqlSession //事务提交[org.apache.ibatis.session.defaults.DefaultSqlSession@32c4821]2017-06-18 14:43:16,098 [http-bio-8080-exec-10] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization deregistering SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@32c4821]

6. 在事务配置中没有设置rollback-for异常类型为Exception

<!-- 事务管理器 -->    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">        <property name="dataSource" ref="dataSource"/>    </bean>    <!-- 通知 -->    <tx:advice id="txAdvice" transaction-manager="transactionManager">        <!-- 事务行为控制 -->        <tx:attributes>            <tx:method name="save" propagation="REQUIRED" rollback-for="Exception"/>            <tx:method name="insert*" propagation="REQUIRED"  rollback-for="Exception"/>            <tx:method name="add*" propagation="REQUIRED"  rollback-for="Exception"/>            <tx:method name="create*" propagation="REQUIRED"  rollback-for="Exception"/>            <tx:method name="delete*" propagation="REQUIRED"  rollback-for="Exception"/>            <tx:method name="update*" propagation="REQUIRED"  rollback-for="Exception"/>            <tx:method name="find*" propagation="SUPPORTS" read-only="true" />            <tx:method name="select*" propagation="SUPPORTS" read-only="true" />            <tx:method name="get*" propagation="SUPPORTS" read-only="true" />        </tx:attributes>    </tx:advice>    <!-- 配置切面 -->    <aop:config>        <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.shop.manager.service.*.*(..))" />    </aop:config>

    /**     * 删除多条记录     * @throws Exception      */    @Override    public ShopResult deleteContentGroup(String[] ids) throws Exception {        if (null == ids || ids.length == 0)        {            return ShopResult.error();        }        for (String idStr : ids)        {            Long id = new Long(idStr);            contentMappger.deleteByPrimaryKey(id);        }        try {            contentMappger.updateWithErrTest(31L);   //错误代码，SQL语句错误。用来测试事务，看是否回滚        } catch (Exception e) {            //捕获异常，继续抛出            System.out.println("-----throw new Exception-------");            throw new Exception("---自定义Exception，事务中已配置rollback-for---");        }        return ShopResult.ok();    }

运行结果：如预期一样发生回滚

### The error may involve com.shop.manager.mapper.TbContentMapper.updateWithErrTest-Inline### The error occurred while setting parameters### SQL: delete form tb_content    where kid = ?### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'tb_content    where kid = 31' at line 1]-----throw new Exception-------2017-06-18 15:07:02,273 [http-bio-8080-exec-8] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization deregistering SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@f177061]2017-06-18 15:07:02,273 [http-bio-8080-exec-8] [org.mybatis.spring.SqlSessionUtils]-[DEBUG] Transaction synchronization closing SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@f177061]

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总结：

1. Spring事务管理是根据异常来进行回滚操作；
2. Spring与Mybatis整合时，虽然在Service方法中并没有check异常，但是如果数据库有异常发生，默认会进行事务回滚。
3. Spring 如果不添加rollbackFor等属性，Spring碰到Unchecked Exceptions都会回滚，不仅是RuntimeException，也包括Error。
4. 如果在事务方法中捕获异常并进行处理，一定要继续抛出异常并在Spring事务管理中进行rollbak-for配置。