Druid数据库连接池异常connection holder is null
具体如下：
### Error updating database. Cause: java.sql.SQLException: connection holder is null ### 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:84) 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$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:371) at com.sun.proxy.$Proxy15.insert(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.insert(SqlSessionTemplate.java:240) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:51) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52) at com.sun.proxy.$Proxy28.insertList(Unknown Source) at com.ajia.data.synchronize.service.score.impl.QuestScoreServiceImpl.insertList(QuestScoreServiceImpl.java:59) at com.ajia.data.synchronize.service.score.impl.QuestScoreServiceImpl$$FastClassBySpringCGLIB$$18f74d0e.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
connection holder 这肯定是连接池的异常，就看看连接池的配置。
#超过时间限制是否回收 removeAbandoned=true #超过时间限制多长 removeAbandonedTimeout=300
解决方法一
我的任务时间比较长，而这个又这么短，就设置长一点，设置成一小时
#超过时间限制多长 removeAbandonedTimeout=3600
解决方法二
直接设置成是不用超时回收连接
removeAbandoned=false
