错误：运行gunsApplication.java报错 “Could not create connection to database server. Attempted reconnect 3 times. Giving up.”

2019-07-07 12:35:53.131  INFO 23364 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'xssFilter' to urls: [/*]

2019-07-07 12:35:53.131  INFO 23364 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'shiroFilter' to: [/*]

2019-07-07 12:35:58.271 ERROR 23364 --- [  restartedMain] com.alibaba.druid.pool.DruidDataSource   : init datasource error, url: jdbc:mysql://127.0.0.1:3306/guns?autoReconnect=true&useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)

at com.mysql.jdbc.Util.getInstance(Util.java:387)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:917)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)

at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2165)

at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2090)

at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:795)

at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)

at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327)

at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:149)

at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:218)

at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:143)

at com.alibaba.druid.filter.FilterAdapter.connection_connect(FilterAdapter.java:786)

at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:143)

at com.alibaba.druid.filter.FilterAdapter.connection_connect(FilterAdapter.java:786)

at com.alibaba.druid.filter.FilterEventAdapter.connection_connect(FilterEventAdapter.java:38)

at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:143)

at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1512)

at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1575)

at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:854)

at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1221)

at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1217)

at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:90)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

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 com.alibaba.druid.support.spring.stat.DruidStatInterceptor.invoke(DruidStatInterceptor.java:72)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)

at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)

at com.sun.proxy.$Proxy96.getConnection(Unknown Source)

at com.baomidou.mybatisplus.toolkit.GlobalConfigUtils.setMetaData(GlobalConfigUtils.java:187)

at com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:560)

at com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean.afterPropertiesSet(MybatisSqlSessionFactoryBean.java:385)

at com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean.getObject(MybatisSqlSessionFactoryBean.java:608)

at com.baomidou.mybatisplus.spring.boot.starter.MybatisPlusAutoConfiguration.sqlSessionFactory(MybatisPlusAutoConfiguration.java:147)

at com.baomidou.mybatisplus.spring.boot.starter.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$d8348a01.CGLIB$sqlSessionFactory$1(<generated>)

at com.baomidou.mybatisplus.spring.boot.starter.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$d8348a01$$FastClassBySpringCGLIB$$7aad1960.invoke(<generated>)

at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)

at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358)

at com.baomidou.mybatisplus.spring.boot.starter.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$d8348a01.sqlSessionFactory(<generated>)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)

at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1342)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1249)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:220)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1018)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:345)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:340)

at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1092)

at com.stylefeng.guns.core.util.SpringContextHolder.getBean(SpringContextHolder.java:37)

at com.stylefeng.guns.core.common.constant.factory.ConstantFactory.<init>(ConstantFactory.java:33)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142)

at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1147)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1099)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)

at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)

at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)

at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)

at com.stylefeng.guns.GunsApplication.main(GunsApplication.java:20)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)