项目是基于springboot框架，昨天从git上pull代码之后也没有具体看更改的地方，结果运行的时候就报错了。
1 java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. 2 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) ~[mysql-connector-java-8.0.13.jar:8.0.13] 3 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) ~[mysql-connector-java-8.0.13.jar:8.0.13] 4 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) ~[mysql-connector-java-8.0.13.jar:8.0.13] 5 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) ~[mysql-connector-java-8.0.13.jar:8.0.13] 6 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) ~[mysql-connector-java-8.0.13.jar:8.0.13] 7 at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:905) ~[mysql-connector-java-8.0.13.jar:8.0.13] 8 at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:830) ~[mysql-connector-java-8.0.13.jar:8.0.13] 9 at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:455) ~[mysql-connector-java-8.0.13.jar:8.0.13] 10 at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.13.jar:8.0.13] 11 at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207) ~[mysql-connector-java-8.0.13.jar:8.0.13] 12 at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar:na] 13 at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na] 14 at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na] 15 at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) [HikariCP-3.2.0.jar:na] 16 at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) [HikariCP-3.2.0.jar:na] 17 at com.zaxxer.hikari.pool.HikariPool. (HikariPool.java:115) [HikariCP-3.2.0.jar:na] 18 at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-3.2.0.jar:na] 19 at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 20 at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 21 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 22 at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:324) [spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 23 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.getProduct(DataSourceHealthIndicator.java:122) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 24 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doDataSourceHealthCheck(DataSourceHealthIndicator.java:109) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 25 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doHealthCheck(DataSourceHealthIndicator.java:104) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 26 at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:84) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 27 at org.springframework.boot.actuate.health.CompositeHealthIndicator.health(CompositeHealthIndicator.java:98) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 28 at org.springframework.boot.actuate.health.HealthEndpoint.health(HealthEndpoint.java:50) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 29 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181] 30 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181] 31 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181] 32 at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181] 33 at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:244) [spring-core-5.1.2.RELEASE.jar:5.1.2.RELEASE] 34 at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:76) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 35 at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:61) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 36 at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:126) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 37 at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:99) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 38 at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) [na:1.8.0_181] 39 at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) [na:1.8.0_181] 40 at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) [na:1.8.0_181] 41 at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76) [na:1.8.0_181] 42 at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) [na:1.8.0_181] 43 at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401) [na:1.8.0_181] 44 at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) [na:1.8.0_181] 45 at sun.reflect.GeneratedMethodAccessor62.invoke(Unknown Source) ~[na:na] 46 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181] 47 at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181] 48 at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357) [na:1.8.0_181] 49 at sun.rmi.transport.Transport$1.run(Transport.java:200) [na:1.8.0_181] 50 at sun.rmi.transport.Transport$1.run(Transport.java:197) [na:1.8.0_181] 51 at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_181] 52 at sun.rmi.transport.Transport.serviceCall(Transport.java:196) [na:1.8.0_181] 53 at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573) [na:1.8.0_181] 54 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834) [na:1.8.0_181] 55 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688) [na:1.8.0_181] 56 at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_181] 57 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687) [na:1.8.0_181] 58 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_181] 59 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_181] 60 at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_181] 61 Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure 62 63 The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. 64 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_181] 65 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_181] 66 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_181] 67 at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_181] 68 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.13.jar:8.0.13] 69 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.13.jar:8.0.13] 70 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.13.jar:8.0.13] 71 at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.13.jar:8.0.13] 72 at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.13.jar:8.0.13] 73 at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.13.jar:8.0.13] 74 at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:849) ~[mysql-connector-java-8.0.13.jar:8.0.13] 75 ... 53 common frames omitted 76 Caused by: java.net.ConnectException: Connection refused: connect 77 at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_181] 78 at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_181] 79 at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_181] 80 at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_181] 81 at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_181] 82 at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_181] 83 at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_181] 84 at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_181] 85 at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.13.jar:8.0.13] 86 at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.13.jar:8.0.13] 87 ... 55 common frames omitted 88 89 2018-12-26 18:25:15.124 WARN 10412 --- [on(2)-127.0.0.1] o.s.b.a.jdbc.DataSourceHealthIndicator : DataSource health check failed 90 91 org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. 92 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81) ~[spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 93 at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:324) ~[spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 94 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.getProduct(DataSourceHealthIndicator.java:122) ~[spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 95 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doDataSourceHealthCheck(DataSourceHealthIndicator.java:109) ~[spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 96 at org.springframework.boot.actuate.jdbc.DataSourceHealthIndicator.doHealthCheck(DataSourceHealthIndicator.java:104) ~[spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 97 at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:84) ~[spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 98 at org.springframework.boot.actuate.health.CompositeHealthIndicator.health(CompositeHealthIndicator.java:98) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 99 at org.springframework.boot.actuate.health.HealthEndpoint.health(HealthEndpoint.java:50) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 100 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181] 101 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181] 102 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181] 103 at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181] 104 at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:244) [spring-core-5.1.2.RELEASE.jar:5.1.2.RELEASE] 105 at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:76) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 106 at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:61) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 107 at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:126) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 108 at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:99) [spring-boot-actuator-2.1.0.RELEASE.jar:2.1.0.RELEASE] 109 at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) [na:1.8.0_181] 110 at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) [na:1.8.0_181] 111 at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) [na:1.8.0_181] 112 at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76) [na:1.8.0_181] 113 at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) [na:1.8.0_181] 114 at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401) [na:1.8.0_181] 115 at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) [na:1.8.0_181] 116 at sun.reflect.GeneratedMethodAccessor62.invoke(Unknown Source) ~[na:na] 117 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181] 118 at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181] 119 at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357) [na:1.8.0_181] 120 at sun.rmi.transport.Transport$1.run(Transport.java:200) [na:1.8.0_181] 121 at sun.rmi.transport.Transport$1.run(Transport.java:197) [na:1.8.0_181] 122 at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_181] 123 at sun.rmi.transport.Transport.serviceCall(Transport.java:196) [na:1.8.0_181] 124 at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573) [na:1.8.0_181] 125 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834) [na:1.8.0_181] 126 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688) [na:1.8.0_181] 127 at java.security.AccessController.doPrivileged(Native Method) [na:1.8.0_181] 128 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687) [na:1.8.0_181] 129 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_181] 130 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_181] 131 at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_181] 132 Caused by: java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. 133 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) ~[mysql-connector-java-8.0.13.jar:8.0.13] 134 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) ~[mysql-connector-java-8.0.13.jar:8.0.13] 135 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) ~[mysql-connector-java-8.0.13.jar:8.0.13] 136 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) ~[mysql-connector-java-8.0.13.jar:8.0.13] 137 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) ~[mysql-connector-java-8.0.13.jar:8.0.13] 138 at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:905) ~[mysql-connector-java-8.0.13.jar:8.0.13] 139 at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:830) ~[mysql-connector-java-8.0.13.jar:8.0.13] 140 at com.mysql.cj.jdbc.ConnectionImpl. (ConnectionImpl.java:455) ~[mysql-connector-java-8.0.13.jar:8.0.13] 141 at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.13.jar:8.0.13] 142 at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207) ~[mysql-connector-java-8.0.13.jar:8.0.13] 143 at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar:na] 144 at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na] 145 at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na] 146 at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar:na] 147 at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) ~[HikariCP-3.2.0.jar:na] 148 at com.zaxxer.hikari.pool.HikariPool. (HikariPool.java:115) ~[HikariCP-3.2.0.jar:na] 149 at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.2.0.jar:na] 150 at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) ~[spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 151 at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) ~[spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 152 at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) ~[spring-jdbc-5.1.2.RELEASE.jar:5.1.2.RELEASE] 153 ... 39 common frames omitted 154 Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure 155 156 The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. 157 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_181] 158 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_181] 159 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_181] 160 at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_181] 161 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.13.jar:8.0.13] 162 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.13.jar:8.0.13] 163 at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.13.jar:8.0.13] 164 at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.13.jar:8.0.13] 165 at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.13.jar:8.0.13] 166 at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.13.jar:8.0.13] 167 at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:849) ~[mysql-connector-java-8.0.13.jar:8.0.13] 168 ... 53 common frames omitted 169 Caused by: java.net.ConnectException: Connection refused: connect 170 at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_181] 171 at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_181] 172 at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_181] 173 at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_181] 174 at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_181] 175 at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_181] 176 at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_181] 177 at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_181] 178 at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.13.jar:8.0.13] 179 at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.13.jar:8.0.13] 180 ... 55 common frames omitted
开始根据报错信息百度，各种方法，包括查看是否自己的路径配置出现问题，或者pom里的jar包引的不对，都没有起到作用，今天上午同事说了一句路径应该是服务器的，不是本地的，才反应过来。
spring.datasource.url=jdbc:mysql://localhost:3306/membercenter?autoReconnect=true&useUnicode=true&characterEncoding=utf8
我是在自己电脑上开发，数据库在服务器上，所以不应该用localhost。