这两天学习springMVC后端代码编写，出现了这个问题
五月 21, 2020 3:04:49 下午 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:boot-crm' did not find a matching property.
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Server version: Apache Tomcat/8.5.11
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Server built: Jan 10 2017 21:02:52 UTC
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Server number: 8.5.11.0
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: OS Name: Windows 10
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: OS Version: 10.0
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Architecture: amd64
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Java Home: C:\Program Files\Java\jdk1.8.0_161\jre
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: JVM Version: 1.8.0_161-b12
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: JVM Vendor: Oracle Corporation
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: CATALINA_BASE: E:\eclipsework\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: CATALINA_HOME: D:\apache-tomcat-8.5.11
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dcatalina.base=E:\eclipsework\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dcatalina.home=D:\apache-tomcat-8.5.11
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dwtp.deploy=E:\eclipsework\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Djava.endorsed.dirs=D:\apache-tomcat-8.5.11\endorsed
五月 21, 2020 3:04:49 下午 org.apache.catalina.startup.VersionLoggerListener log
信息: Command line argument: -Dfile.encoding=GBK
五月 21, 2020 3:04:49 下午 org.apache.catalina.core.AprLifecycleListener lifecycleEvent
信息: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jdk1.8.0_161\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jdk1.8.0_161/bin/../jre/bin/server;C:/Program Files/Java/jdk1.8.0_161/bin/../jre/bin;C:/Program Files/Java/jdk1.8.0_161/bin/../jre/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\Program Files\Java\jdk1.8.0_161\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files (x86)\MySQL\MySQL Server 5.5\bin;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Program Files\Microsoft\Web Platform Installer\;C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\;C:\Program Files (x86)\Windows Kits\8.0\Windows Performance Toolkit\;C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;D:\VisualSVN-Server-4.1.3-x64\bin;D:\TortoiseSVN\bin;D:\maven\apache-maven-3.6.3\bin\;C:\Program Files\MySQL\MySQL Shell 8.0\bin\;C:\Users\张玉荣\AppData\Local\Microsoft\WindowsApps;C:\Program Files\MySQL\MySQL Server 5.6\bin;;E:\eclipse;;.
五月 21, 2020 3:04:49 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["http-nio-8080"]
五月 21, 2020 3:04:50 下午 org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
信息: Using a shared selector for servlet write/read
五月 21, 2020 3:04:50 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["ajp-nio-8009"]
五月 21, 2020 3:04:50 下午 org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
信息: Using a shared selector for servlet write/read
五月 21, 2020 3:04:50 下午 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1833 ms
五月 21, 2020 3:04:50 下午 org.apache.catalina.core.StandardService startInternal
信息: Starting service Catalina
五月 21, 2020 3:04:50 下午 org.apache.catalina.core.StandardEngine startInternal
信息: Starting Servlet Engine: Apache Tomcat/8.5.11
五月 21, 2020 3:04:54 下午 org.apache.jasper.servlet.TldScanner scanJars
信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
五月 21, 2020 3:04:54 下午 org.apache.catalina.core.ApplicationContext log
信息: No Spring WebApplicationInitializer types detected on classpath
五月 21, 2020 3:04:54 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
五月 21, 2020 3:04:59 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring FrameworkServlet 'crm'
五月 21, 2020 3:05:01 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler [http-nio-8080]
五月 21, 2020 3:05:01 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler [ajp-nio-8009]
五月 21, 2020 3:05:01 下午 org.apache.catalina.startup.Catalina start
信息: Server startup in 10963 ms
五月 21, 2020 3:05:32 下午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [crm] in context with path [/boot-crm] threw exception [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: Could not get JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
### The error may exist in com/itheima/core/dao/UserDao.xml
### The error may involve com.itheima.core.dao.UserDao.findUser
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)] with root cause
java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:300)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2251)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
at org.apache.commons.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:39)
at org.apache.commons.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:256)
at org.apache.commons.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:2304)
at org.apache.commons.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2290)
at org.apache.commons.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:2039)
at org.apache.commons.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1533)
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 org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)
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$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
at com.sun.proxy.$Proxy13.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:82)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
at com.sun.proxy.$Proxy21.findUser(Unknown Source)
at com.itheima.core.service.impl.UserServiceImpl.findUser(UserServiceImpl.java:23)
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:333)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy22.findUser(Unknown Source)
at com.itheima.core.web.controller.UserController.login(UserController.java:26)
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:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
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)
五月 21, 2020 3:12:29 下午 org.apache.catalina.core.StandardContext reload
信息: Reloading Context with name [/boot-crm] has started
五月 21, 2020 3:12:29 下午 org.apache.catalina.core.ApplicationContext log
信息: Destroying Spring FrameworkServlet 'crm'
五月 21, 2020 3:12:29 下午 org.apache.catalina.core.ApplicationContext log
信息: Closing Spring root WebApplicationContext
五月 21, 2020 3:12:29 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
警告: The web application [boot-crm] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
五月 21, 2020 3:12:29 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
警告: The web application [boot-crm] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)
五月 21, 2020 3:12:35 下午 org.apache.jasper.servlet.TldScanner scanJars
信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
五月 21, 2020 3:12:35 下午 org.apache.catalina.core.ApplicationContext log
信息: No Spring WebApplicationInitializer types detected on classpath
五月 21, 2020 3:12:35 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
五月 21, 2020 3:12:38 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring FrameworkServlet 'crm'
五月 21, 2020 3:12:40 下午 org.apache.catalina.core.StandardContext reload
信息: Reloading Context with name [/boot-crm] is completed
五月 21, 2020 3:14:42 下午 org.apache.catalina.core.StandardContext reload
信息: Reloading Context with name [/boot-crm] has started
五月 21, 2020 3:14:42 下午 org.apache.catalina.core.ApplicationContext log
信息: Destroying Spring FrameworkServlet 'crm'
五月 21, 2020 3:14:42 下午 org.apache.catalina.core.ApplicationContext log
信息: Closing Spring root WebApplicationContext
五月 21, 2020 3:14:45 下午 org.apache.jasper.servlet.TldScanner scanJars
信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
五月 21, 2020 3:14:45 下午 org.apache.catalina.core.ApplicationContext log
信息: No Spring WebApplicationInitializer types detected on classpath
五月 21, 2020 3:14:45 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
五月 21, 2020 3:14:49 下午 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring FrameworkServlet 'crm'
五月 21, 2020 3:14:51 下午 org.apache.catalina.core.StandardContext reload
信息: Reloading Context with name [/boot-crm] is completed
你可以去查看一下你的连接数据库的配置文件是否有错，末尾是否不小心写了空格
如果以上没有问题就去检查看看你的是否把mysql启动了！！！！！