Mybatis入庫出現異常后，如何捕捉異常

　　一個同事在調試Mybatis更新操作，沒有任何sql語句打印，sql語句也沒執行。

　　跟了下Mybatis的MapperProxy類的invoke方法，跟到拼裝sql語句的地方，確實拋出了異常，但是控制台確實沒有打印，其他的sql語句都有打印。

       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拋出的異常SQLSyntaxErrorException，spring框架會封裝成DataAccessException，DataAccessException是RuntimeException的子類，不捕獲的話就會一層一層往外拋。

        先看看解決的辦法：

　　1.在 Mapper 接口里拋出 DataAccessException 異常

　　2.在 ServiceImpl 里，調用了該 Mapper 接口的方法上捕獲 DataAccessException 異常，再向外拋出DataAccessException

       3.在 Controller 里捕獲 DataAccessException 異常並返回提示

       我試了下，Mapper 接口里不拋出 DataAccessException 異常，ServiceImpl也是可以捕獲DataAccessException異常的。

　　

        看一下，捕獲DataAccessException異常后的堆棧：

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:\workspace\xxx\xxx.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的子類，還有DataIntegrityViolationException，DataIntegrityViolationException等也是DataAccessException的子類。

       捕獲到DataAccessException后，是否需要給客戶端返回具體信息，仁者見仁，我的理解是不用給客戶展示太多的錯誤信息。但是錯誤堆棧總是要打印出來的，要不然出來個死鎖之類的就麻煩了。