org.apache.ibatis.exceptions.PersistenceExceptio？

Question

02-Apr-2021 16:37:21.967 信息 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log No Spring WebApplicationInitializer types detected on classpath
02-Apr-2021 16:37:21.986 信息 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Initializing Spring root WebApplicationContext
02-Apr-2021 16:37:25.909 信息 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Initializing Spring DispatcherServlet 'springmvc'
02-Apr-2021 16:37:28.232 严重 [http-nio-8080-exec-1] org.apache.catalina.core.StandardWrapperValve.invoke 在路径为的上下文中，Servlet[springmvc]的Servlet.service（）引发了具有根本原因的异常Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: com.mysql.cj.jdbc.Driver
### The error may exist in file [/Users/lijch/Downloads/pro/out/artifacts/web_Web_exploded/WEB-INF/classes/mapper/UBookDao.xml]
### The error may involve com.book.dao.UBookDao.getUBookList
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: com.mysql.cj.jdbc.Driver
    java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1365)
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:264)
        at com.alibaba.druid.util.JdbcUtils.createDriver(JdbcUtils.java:518)
        at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:581)
        at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:890)
        at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:886)
        at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:96)
        at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158)
        at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116)
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79)
        at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80)
        at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67)
        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 com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:108)
        at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
        at com.sun.proxy.$Proxy34.query(Unknown Source)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)
        at com.sun.proxy.$Proxy17.selectList(Unknown Source)
        at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:223)
        at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:137)
        at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:75)
        at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)
        at com.sun.proxy.$Proxy24.getUBookList(Unknown Source)
        at com.book.service.impl.UBookServiceImpl.getUBookList(UBookServiceImpl.java:55)
        at com.book.service.impl.UBookApiImpl.getUBookList(UBookApiImpl.java:29)
        at com.book.controller.IndexController.index(IndexController.java:27)
        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:105)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:626)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:880)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1601)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:748)
 

Answer 1

关键提示ClassNotFoundException: com.mysql.cj.jdbc.Driver 根据自己数据库版本，选择正确版本的驱动依赖。mysql低版本用的com.mysql.jdbc.Driver，高版本用的com.mysql.cj.jdbc.Driver。