IDEA报错Cannot load JDBC driver class 'com.mysql.jdbc.Driver'
Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@52700370] was not registered for synchronization because synchronization is not active
Cannot load JDBC driver class ‘com.mysql.jdbc.Driver’
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1291)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1130)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at com.baomidou.mybatisplus.entity.GlobalConfiguration.setMetaData(GlobalConfiguration.java:255)
at com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:530)
at com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean.afterPropertiesSet(MybatisSqlSessionFactoryBean.java:387)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:753)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4745)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5207)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1736)
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:497)
at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
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:497)
at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
at javax.management.remote.rmi.RMIConnectionImpl.access 300 ( R M I C o n n e c t i o n I m p l . j a v a : 76 ) a t j a v a x . m a n a g e m e n t . r e m o t e . r m i . R M I C o n n e c t i o n I m p l 300(RMIConnectionImpl.java:76) at javax.management.remote.rmi.RMIConnectionImpl 300(RMIConnectionImpl.java:76)atjavax.management.remote.rmi.RMIConnectionImplPrivilegedOperation.run(RMIConnectionImpl.java:1309)
at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
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:497)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport 1. r u n ( T r a n s p o r t . j a v a : 197 ) a t j a v a . s e c u r i t y . A c c e s s C o n t r o l l e r . d o P r i v i l e g e d ( N a t i v e M e t h o d ) a t s u n . r m i . t r a n s p o r t . T r a n s p o r t . s e r v i c e C a l l ( T r a n s p o r t . j a v a : 196 ) a t s u n . r m i . t r a n s p o r t . t c p . T C P T r a n s p o r t . h a n d l e M e s s a g e s ( T C P T r a n s p o r t . j a v a : 568 ) a t s u n . r m i . t r a n s p o r t . t c p . T C P T r a n s p o r t 1.run(Transport.java:197) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:196) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568) at sun.rmi.transport.tcp.TCPTransport 1.run(Transport.java:197)atjava.security.AccessController.doPrivileged(NativeMethod)atsun.rmi.transport.Transport.serviceCall(Transport.java:196)atsun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)atsun.rmi.transport.tcp.TCPTransportConnectionHandler.run0(TCPTransport.java:826)
at sun.rmi.transport.tcp.TCPTransport C o n n e c t i o n H a n d l e r . l a m b d a ConnectionHandler.lambda ConnectionHandler.lambdarun 256 ( T C P T r a n s p o r t . j a v a : 683 ) a t j a v a . s e c u r i t y . A c c e s s C o n t r o l l e r . d o P r i v i l e g e d ( N a t i v e M e t h o d ) a t s u n . r m i . t r a n s p o r t . t c p . T C P T r a n s p o r t 256(TCPTransport.java:683) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport 256(TCPTransport.java:683)atjava.security.AccessController.doPrivileged(NativeMethod)atsun.rmi.transport.tcp.TCPTransportConnectionHandler.run(TCPTransport.java:682)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Cannot load JDBC driver class ‘com.mysql.jdbc.Driver’
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1291)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1130)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82)
at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68)
at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:336)
at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:84)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
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:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.jaClosing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@52700370]
本来之前就可以连接上远程的数据库，因为电脑重启了一次，因此许多关于idea的配置没了。
解决：不是网上说的那种多了空格或者是在pom.xml中加入了驱动配置。而是配置了war的输出路径以及在tomcat中加载对应的东西（半路出家造成的坑）。
以下图片说明吧。
可以展开WEB-INF文件夹，里面有lib，然后可以找到对应的mysql-connect的包。正是这个没配置好，才导致上述错误吧。
总之，就是配置没配好。