The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received

ql.cj.jdbc.exceptions.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 com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:172)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:862)
at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:444)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:230)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:226)
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138)
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206)
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:477)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:560)
at com.zaxxer.hikari.pool.HikariPool.(HikariPool.java:115)
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112)
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.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:324)
at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.isEmbedded(EmbeddedDatabaseConnection.java:133)
at org.springframework.boot.autoconfigure.orm.jpa.HibernateDefaultDdlAutoProvider.getDefaultDdlAuto(HibernateDefaultDdlAutoProvider.java:42)
at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration.lambda$getVendorProperties$1(HibernateJpaConfiguration.java:130)atorg.springframework.boot.autoconfigure.orm.jpa.HibernateSettings.getDdlAuto(HibernateSettings.java:41)atorg.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.determineDdlAuto(HibernateProperties.java:136)atorg.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.getAdditionalProperties(HibernateProperties.java:102)atorg.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.determineHibernateProperties(HibernateProperties.java:94)atorg.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration.getVendorProperties(HibernateJpaConfiguration.java:132)atorg.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.entityManagerFactory(JpaBaseConfiguration.java:133)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)atjava.lang.reflect.Method.invoke(Method.java:498)atorg.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)atorg.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:652)atorg.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:637)atorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336)atorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1176)atorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556)atorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516)atorg.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1109)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:405)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
at paas.api.WebApiApplication.main(WebApiApplication.java:16)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

当出现上述报错，可以检查一下application里面的数据库连接相关的配置！