Mybatis入库出现异常后，如何捕捉异常

　　一个同事在调试Mybatis更新操作，没有任何sql语句打印，sql语句也没执行。

　　跟了下Mybatis的MapperProxy类的invoke方法，跟到拼装sql语句的地方，确实抛出了异常，但是控制台确实没有打印，其他的sql语句都有打印。

       springboot的application配置文件中加上了logging.level.xxx.xxx.xxx.xxx.mapper=debug，正常是要打印sql的。

        查了下，Mybatis抛出的异常SQLSyntaxErrorException，spring框架会封装成DataAccessException，DataAccessException是RuntimeException的子类，不捕获的话就会一层一层往外抛。

        先看看解决的办法：

　　1.在 Mapper 接口里抛出 DataAccessException 异常

　　2.在 ServiceImpl 里，调用了该 Mapper 接口的方法上捕获 DataAccessException 异常，再向外抛出DataAccessException

       3.在 Controller 里捕获 DataAccessException 异常并返回提示

       我试了下，Mapper 接口里不抛出 DataAccessException 异常，ServiceImpl也是可以捕获DataAccessException异常的。

　　

        看一下，捕获DataAccessException异常后的堆栈：

java.sql.SQLSyntaxErrorException: Table 'xxx.xxx' doesn't exist
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953)
    at com.mysql.cj.jdbc.ClientPreparedStatement.execute(ClientPreparedStatement.java:370)
    at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3409)
    at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_execute(FilterEventAdapter.java:440)
    at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3407)
    at com.alibaba.druid.wall.WallFilter.preparedStatement_execute(WallFilter.java:619)
    at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3407)
    at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_execute(FilterEventAdapter.java:440)
    at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3407)
    at com.alibaba.druid.proxy.jdbc.PreparedStatementProxyImpl.execute(PreparedStatementProxyImpl.java:167)
    at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:498)
    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.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:59)
    at com.sun.proxy.$Proxy85.execute(Unknown Source)
    at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63)
    at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
    at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
    at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
    at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
    at com.sun.proxy.$Proxy71.selectOne(Unknown Source)
    at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
    at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:83)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
    at com.sun.proxy.$Proxy72.selectByRelayId(Unknown Source)
    ...
    at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
    at java.lang.Thread.run(Thread.java:748)

org.springframework.jdbc.BadSqlGrammarException: 
### Error querying database.  Cause: java.sql.SQLSyntaxErrorException: Table 'xxx.xxx' doesn't exist
### The error may exist in file [D:workspacexxxxxx.xml]
### The error may involve xxx.xxxMapper.selectByRelayId-Inline
### The error occurred while setting parameters
### SQL: xxxx where relay_id = ?
### Cause: java.sql.SQLSyntaxErrorException: Table 'xxx.xxx' doesn't exist
; bad SQL grammar []; nested exception is java.sql.SQLSyntaxErrorException: Table 'xxx.xxx' doesn't exist
    at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:235)
    at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)
    at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
    at com.sun.proxy.$Proxy71.selectOne(Unknown Source)
    at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
    at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:83)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
    at com.sun.proxy.$Proxy72.selectByRelayId(Unknown Source)

　　BadSqlGrammarException是DataAccessException的子类，还有DataIntegrityViolationException，DataIntegrityViolationException等也是DataAccessException的子类。

       捕获到DataAccessException后，是否需要给客户端返回具体信息，仁者见仁，我的理解是不用给客户展示太多的错误信息。但是错误堆栈总是要打印出来的，要不然出来个死锁之类的就麻烦了。