Caused by: java.net.ConnectException: Connection refused: connect

一、启动项目报错之数据库服务未开启（Caused by: java.net.ConnectException: Connection refused: connect）

2020-12-22 18:28:51.325  INFO 16656 [1)-192.168.0.26] com.zaxxer.hikari.HikariDataSource       [110] : HikariPool-1 - Starting... 
2020-12-22 18:28:51.337  INFO 16656 [2)-192.168.0.26] o.s.web.servlet.DispatcherServlet        [512] : FrameworkServlet 'dispatcherServlet': initialization completed in 24 ms 
2020-12-22 18:28:54.619 ERROR 16656 [1)-192.168.0.26] com.zaxxer.hikari.pool.HikariPool        [567] : HikariPool-1 - Exception during pool initialization. 
 
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: 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. 
        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.SQLError.createCommunicationsException(SQLError.java:990) 
        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:342) 
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2197) 
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2230) 
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2025) 
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:778) 
        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:386) 
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) 
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:117) 
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:123) 
        at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:365) 
        at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:194) 
        at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:460) 
        at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:534) 
        at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) 
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) 
        at com.zaxxer.hikari.HikariDataSource$$FastClassBySpringCGLIB$$eeb1ae86.invoke(<generated>) 
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) 
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746) 
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) 
        at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:136) 
        at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:124) 
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) 
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688) 
        at com.zaxxer.hikari.HikariDataSource$$EnhancerBySpringCGLIB$$b97a9569.getConnection(<generated>) 
        at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157) 
        at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) 
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) 
        at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:324) 
        at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.getProduct(DataSourceHealthIndicator.java:122) 
        at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doDataSourceHealthCheck(DataSourceHealthIndicator.java:109) 
        at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doHealthCheck(DataSourceHealthIndicator.java:104) 
        at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:84) 
        at org.springframework.boot.actuate.health.CompositeHealthIndicator.health(CompositeHealthIndicator.java:68) 
        at org.springframework.boot.actuate.health.HealthEndpoint.health(HealthEndpoint.java:47) 
        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.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:246) 
        at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:76) 
        at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:61) 
        at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:126) 
        at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:99) 
        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$300(RMIConnectionImpl.java:76) 
        at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.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:498) 
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357) 
        at sun.rmi.transport.Transport$1.run(Transport.java:200) 
        at sun.rmi.transport.Transport$1.run(Transport.java:197) 
        at java.security.AccessController.doPrivileged(Native Method) 
        at sun.rmi.transport.Transport.serviceCall(Transport.java:196) 
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573) 
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834) 
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688) 
        at java.security.AccessController.doPrivileged(Native Method) 
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) 
        at java.lang.Thread.run(Thread.java:748) 
Caused by: java.net.ConnectException: Connection refused: connect 
        at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) 
        at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) 
        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:606) 
        at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211) 
        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:301) 
        ... 72 common frames omitted 
 
2020-12-22 18:28:54.628  WARN 16656 [1)-192.168.0.26] o.s.b.a.jdbc.DataSourceHealthIndicator   [89] : DataSource health check failed 
 

        ... 72 common frames omitted 

二、错误原因未启动mysql服务

三、解决方法，启动mysql服务

• net start mysql （对应的服务关闭命令为 net stop mysql）