(No operations allowed after connection closed.).Possibly consider using a shorter maxLifetime value

这两天碰到一个问题，在正常查询数据时，没有问题，但在使用多线程查询数据导出时，会报以下错误：

2020-05-21 08:40:36.639  WARN [charger-business,,,] 13736 --- [ool-20-thread-6] com.zaxxer.hikari.pool.PoolBase          : HikariPool-1 - Failed to validate connection com.mysql.cj.jdbc.ConnectionImpl@167038d (No operations allowed after connection closed.). Possibly consider using a shorter maxLifetime value.
2020-05-21 08:40:36.686 ERROR [charger-business,4ac1589793274508,eda600f847a74923,true] 13736 --- [  XNIO-1 task-5] c.p.c.b.s.i.TOrderChargingServiceImpl    : 多线程查询导出数据失败,查询参数：{"current":1,"mergeOrderFlag":0,"settlementEndTime":"2020-06-01","settlementStartTime":"2020-04-01","size":20},具体错误：{}

java.util.concurrent.ExecutionException: org.springframework.dao.TransientDataAccessResourceException: 
### Error querying database.  Cause: java.sql.SQLException
### The error may exist in file [F:\IDEA_Workspace\Platform20190828\charger-business\charger-business-biz\target\classes\mapper\TOrderChargingMapper.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: select             a.`id`,       a.`uuid`,       a.`order_no`,       a.`order_name`,       CASE a.`is_over` WHEN 0 THEN '未完成' WHEN 1 THEN '已完成' WHEN 2 THEN '异常订单' ELSE '未知状态 ' END AS is_over,       CASE a.`receive_flag` WHEN 1 THEN '已上报' WHEN 2 THEN '待上报' ELSE '未上报' END AS receive_flag,       a.`user_id`,       a.`user_name`,       a.`vin`,       CASE a.`user_type` WHEN 0 THEN 'APP' WHEN 1 THEN '刷卡' WHEN 2 THEN 'VIN' WHEN 3 THEN '企业用户' WHEN 4 THEN '微信公众号' WHEN 5 THEN '互联互通' ELSE '未知类型' END AS user_type,       a.`agent_id`,       a.`agent_name`,        CASE ifnull(a.`company_flag`,0) WHEN 0 THEN '普通订单' WHEN 1 THEN '企业订单'  ELSE '未知类型订单' END AS company_flag,       a.`company_id`,       a.`company_name`,         CASE ifnull(a.`order_type`,1) WHEN 1 THEN '刷卡在线充电' WHEN 2 THEN '移动app充电'  WHEN 3 THEN 'vin充电' WHEN 4 THEN '刷卡离线充电' WHEN 5 THEN '微信公众号充电' WHEN 6 THEN '微信小程序充电' ELSE '未知类型订单' END AS order_type,        CASE a.`order_flag` WHEN 0 THEN '平台订单' WHEN 1 THEN  '第三方平台订单' ELSE '未知订单标志' END AS order_flag,       CASE a.`pay_status` WHEN 0 THEN '未支付' WHEN 1 THEN  '已支付' ELSE '未知状态' END AS pay_status,       a.`start_time`,       a.`end_time`,       CASE a.`charging_type` WHEN 1 THEN '电量控制充电' WHEN 2 THEN '时间控制充电' WHEN 3 THEN '金额控制充电' WHEN 4 THEN '自动充满05' WHEN 5 THEN '定时启动充电' ELSE '未知充电方式' END charging_type,       a.`charging_number`,       a.`charging_mark`,       a.`start_soc`,       a.`end_soc`,       a.`total_elec`,       a.`start_meter`,       a.`end_meter`,       a.`start_amount`,       a.`end_amount`,       a.`charging_fee`,       a.`service_fee`,       a.`total_amount`,       a.`actual_amount`,       a.`service_id`,       CASE a.`invoice_flag` WHEN 0 THEN '不开发票' ELSE '开具发票' END AS invoice_flag,       a.`pile_id`,       a.`pile_sn`,       a.`pile_name`,       a.`communication_sn`,       a.`drive_no`,       a.`gun_id`,       a.`gun_no`,       a.`tcu_sn`,       CASE a.`gun_type` WHEN 0 THEN '交流' WHEN 1 THEN '直流' WHEN 2 THEN'交直流一体' ELSE '' END AS gun_type,       a.`station_id`,       a.`station_name`,       CASE a.`parking_fee_flag` WHEN 0 THEN '免费' ELSE '收费' END AS parking_fee_flag,       a.`stop_reason`,       a.`create_by`,       a.`create_time`,       a.`update_by`,       a.`update_time`,      CASE WHEN a.`total_time` IS NULL THEN CONCAT(0,'小时',0,'分',0,'秒') WHEN a.`total_time` >= 60 THEN CONCAT(floor(a.`total_time`/3600),'小时',floor(a.`total_time`%3600/60), '分',a.`total_time`%3600%60%60,'秒') ELSE CONCAT(0,'小时',0,'分',a.`total_time`,'秒')END total_time,        a.`user_short_id`,       a.`vendor_id`,       a.`stop_details`,       CASE a.`stop_status` WHEN 0 THEN '正常结束' WHEN 1 THEN  '异常结束' ELSE '' END AS stop_status         FROM `t_order_charging` a      WHERE  a.settlement_time >= ?                       and a.settlement_time <= ?                                                   and a.merge_order_flag = ?                                                and a.del_flag = 0      order by id desc                  limit ?,?
### Cause: java.sql.SQLException
; null; nested exception is java.sql.SQLException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl.mutiThreadQueryExportList(TOrderChargingServiceImpl.java:1647)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl.getExportList(TOrderChargingServiceImpl.java:760)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl$$FastClassBySpringCGLIB$$f4f68c25.invoke()
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:684)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl$$EnhancerBySpringCGLIB$$b6e72552.getExportList()
	at com.platform.charger.business.controller.ChargerOrderController.exportOrderlist(ChargerOrderController.java:209)
	at com.platform.charger.business.controller.ChargerOrderController$$FastClassBySpringCGLIB$$8a7a3b8e.invoke()
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
	at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
	at com.platform.charger.common.log.aspect.SysLogAspect.around(SysLogAspect.java:31)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
	at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
	at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175)
	at org.springframework.security.access.intercept.aopalliance.MethodSecurityInterceptor.invoke(MethodSecurityInterceptor.java:69)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
	at com.platform.charger.business.controller.ChargerOrderController$$EnhancerBySpringCGLIB$$369bd48.exportOrderlist()
	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.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:665)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:750)
	at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
	at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.oauth2.provider.authentication.OAuth2AuthenticationProcessingFilter.doFilter(OAuth2AuthenticationProcessingFilter.java:176)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:74)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.cloud.sleuth.instrument.web.ExceptionLoggingFilter.doFilter(ExceptionLoggingFilter.java:50)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at brave.servlet.TracingFilter.doFilter(TracingFilter.java:86)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:114)
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:104)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
	at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
	at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
	at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
	at io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68)
	at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132)
	at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
	at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
	at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
	at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
	at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130)
	at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
	at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78)
	at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99)
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:376)
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.dao.TransientDataAccessResourceException: 
### Error querying database.  Cause: java.sql.SQLException
### The error may exist in file [F:\IDEA_Workspace\Platform20190828\charger-business\charger-business-biz\target\classes\mapper\TOrderChargingMapper.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: select             a.`id`,       a.`uuid`,       a.`order_no`,       a.`order_name`......        FROM `t_order_details` a      WHERE  a.del_flag = 0      order by id desc                  limit ?,?
### Cause: java.sql.SQLException
; null; nested exception is java.sql.SQLException
	at org.springframework.jdbc.support.SQLStateSQLExceptionTranslator.doTranslate(SQLStateSQLExceptionTranslator.java:110)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
	at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
	at com.sun.proxy.$Proxy175.selectList(Unknown Source)
	at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:230)
	at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.executeForMany(MybatisMapperMethod.java:158)
	at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.execute(MybatisMapperMethod.java:76)
	at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:62)
	at com.sun.proxy.$Proxy237.getExportList(Unknown Source)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl$1.call(TOrderChargingServiceImpl.java:1656)
	at com.platform.charger.business.service.impl.TOrderChargingServiceImpl$1.call(TOrderChargingServiceImpl.java:1654)
	at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
	at java.util.concurrent.FutureTask.run(FutureTask.java)
	... 3 common frames omitted
Caused by: java.sql.SQLException: null
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
	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.zaxxer.hikari.pool.ProxyPreparedStatement.execute(ProxyPreparedStatement.java:44)
	at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.execute(HikariProxyPreparedStatement.java)
	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.$Proxy368.execute(Unknown Source)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:64)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
	at sun.reflect.GeneratedMethodAccessor437.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)
	at com.sun.proxy.$Proxy367.query(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor437.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)
	at com.sun.proxy.$Proxy367.query(Unknown Source)
	at com.baomidou.mybatisplus.core.executor.MybatisSimpleExecutor.doQuery(MybatisSimpleExecutor.java:67)
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
	... 13 common frames omitted

根据错误提示，查看问题：

Cause: java.sql.SQLException
; null; nested exception is java.sql.SQLException

Caused by: java.sql.SQLException: null，

Caused by: org.springframework.dao.TransientDataAccessResourceException:

这些提示看不出问题，那就把SQL语句抓出来在数据库执行下。。发现SQL语句也是正常的。

那好吧，，我仔细找一下错误，，发现在报错前，有一个警告提示：

HikariPool-1 - Failed to validate connection com.mysql.cj.jdbc.ConnectionImpl@167038d (No operations allowed after connection closed.). Possibly consider using a shorter maxLifetime value.

根据提示所说，修改 配置中的 maxLifetime值，

spring:
  datasource:
    type: com.zaxxer.hikari.HikariDataSource
    hikari :
      max-lifetime: 1200000
      connection-timeout: 60000
      validation-timeout: 3000
      idle-timeout: 30000
      minimum-idle: 10
      maximum-pool-size: 10
      connection-test-query: select 1

重启后发现没有什么用。。。
去网上搜索了一下相关问题，，大部分也是说修改maxLifetime值。。

好吧，，去找一下作者怎么说吧。。

上图翻译过来是说在五种情况下HikariCP会关闭连接，分别是连接验证失败、连接闲置时间超过idleTimeout、一个连接到达了它maxLifetime、用户手动驱逐连接、一个JDBC调用抛出一个不可恢复的 SQLException。

在搜索个问题，，现时搜索到了另外一篇博文，也记载了相关的问题，而且给出查找过程及解决原因：
http://www.iocoder.cn/HikariCP/zhazhawangzi/poan-1/

参考其解决方法，发现跟我现在的情况很是相似。先说一下我的开发环境。

我的内部网络地址：10.11.1.111
mysql数据库地址：192.168.18.11

因为我的电脑与mysql数据库不在同一网段，之前两个网段是无法通信的，但经过网络部处理后，使得我方网段可以访问18段的个别地址，注意，不是全部可以访问18段的地址。。估计也是使用了代理或桥接的方式。。

那就把项目部署到mysql所在的服务器试试。。。。

结果完美解决……

坑…………

有遇到这个坑的，欢迎留言讨论。