mysql执行查询报的一个数据库连接池的错误

Question

org.springframework.jdbc.UncategorizedSQLException:
### Error querying database.  Cause: java.sql.SQLException: connection holder is null
### The error may exist in URL [jar:file:/home/server/apache-tomcat-8.5.38/webapps/p6s/WEB-INF/lib/echosoft-erp-impl-1.0.jar!/com/echosoft/erp/dao/impl/DeviceInfoDao.xml]
### The error may involve com.echosoft.erp.dao.IDeviceInfoDao.selectByDid
### The error occurred while executing a query
### SQL: SELECT did FROM `echo_erp`.t_xr_device_info_nglspn WHERE did = ? LIMIT 1
### Cause: java.sql.SQLException: connection holder is null
; uncategorized SQLException for SQL []; SQL state [null]; error code [0]; connection holder is null; nested exception is java.sql.SQLException: connection holder is null
        at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:83)
        at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:80)
        at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:80)
        at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
        at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:371)
        at com.sun.proxy.$Proxy572.selectOne(Unknown Source)
        at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:163)
        at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:68)
        at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52)
        at com.sun.proxy.$Proxy597.selectByDid(Unknown Source)
        at com.echosoft.erp.service.impl.UserDeviceService.initData(UserDeviceService.java:2786)
        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:317)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at com.sun.proxy.$Proxy606.initData(Unknown Source)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

什么原因

Answer 1

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检查你的数据库连接配置，确保连接池可用，并尝试重启应用或调整连接池参数。如果问题依然存在，排查服务器资源和SQL语句是否正确。