如果你和我一样从github或码云上下载了一个几年前别人写的demo代码，想用来做学习用。编译的时候遇到下面这样的错误，然后死命上网查各种方案，百试不灵。试尽了各种方案，就是还连接不上数据库。你可以试一下我经历了多么痛才领悟出来的方法：
有可能是引用的mysql-connector-java包和你安装的数据库不匹配啊！快去检查一下你MySQL Server版本吧。
引入与MySQL版本匹配的包
<dependency> <groupId>mysqlgroupId> <artifactId>mysql-connector-javaartifactId> <version>8.0.13version> dependency>
异常栈
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) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.Util.getInstance(Util.java:384) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2405) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2326) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) ~[mysql-connector-java-5.1.30.jar:na] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344) ~[mysql-connector-java-5.1.30.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:667) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.16.jar:na] at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) [spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) [spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:326) [spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:366) [spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:72) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:139) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:105) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44.CGLIB$jpaVendorAdapter$3(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44$$FastClassBySpringCGLIB$$2d9802e6.invoke(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44.jpaVendorAdapter(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at boss.portal.JwtAuthApplication.main(JwtAuthApplication.java:17) [classes/:na] Caused by: java.lang.NullPointerException: null at com.mysql.jdbc.ConnectionImpl.getServerCharacterEncoding(ConnectionImpl.java:3307) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1985) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1911) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2344) ~[mysql-connector-java-5.1.30.jar:na] ... 83 common frames omitted 2018-12-14 21:30:58.936 WARN 30162 --- [ main] o.s.b.a.orm.jpa.DatabaseLookup : Unable to determine jdbc url from datasource org.springframework.jdbc.support.MetaDataAccessException: Could not get Connection for extracting meta data; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:339) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:366) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:72) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:139) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:105) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44.CGLIB$jpaVendorAdapter$3(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44$$FastClassBySpringCGLIB$$2d9802e6.invoke(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$ba418d44.jpaVendorAdapter(<generated>) [spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at boss.portal.JwtAuthApplication.main(JwtAuthApplication.java:17) [classes/:na] Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:326) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] ... 61 common frames omitted Caused by: 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) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.Util.getInstance(Util.java:384) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2405) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2326) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) ~[mysql-connector-java-5.1.30.jar:na] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344) ~[mysql-connector-java-5.1.30.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:667) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) ~[tomcat-jdbc-8.5.16.jar:na] at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) ~[spring-jdbc-4.3.10.RELEASE.jar:4.3.10.RELEASE] ... 62 common frames omitted Caused by: java.lang.NullPointerException: null at com.mysql.jdbc.ConnectionImpl.getServerCharacterEncoding(ConnectionImpl.java:3307) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1985) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1911) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2344) ~[mysql-connector-java-5.1.30.jar:na] ... 83 common frames omitted 2018-12-14 21:30:59.012 INFO 30162 --- [ main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default' 2018-12-14 21:30:59.050 INFO 30162 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [ name: default ...] 2018-12-14 21:30:59.210 INFO 30162 --- [ main] org.hibernate.Version : HHH000412: Hibernate Core {5.0.12.Final} 2018-12-14 21:30:59.214 INFO 30162 --- [ main] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found 2018-12-14 21:30:59.216 INFO 30162 --- [ main] org.hibernate.cfg.Environment : HHH000021: Bytecode provider name : javassist 2018-12-14 21:30:59.298 INFO 30162 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.0.1.Final} 2018-12-14 21:31:03.964 ERROR 30162 --- [ main] o.a.tomcat.jdbc.pool.ConnectionPool : Unable to create initial connections of pool. 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) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.Util.getInstance(Util.java:384) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2405) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2326) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) ~[mysql-connector-java-5.1.30.jar:na] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_161] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_161] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_161] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_161] at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344) ~[mysql-connector-java-5.1.30.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:667) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.16.jar:na] at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.16.jar:na] at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:254) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:228) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111) [hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) [hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) [hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) [spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) [spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370) [spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359) [spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) [spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at boss.portal.JwtAuthApplication.main(JwtAuthApplication.java:17) [classes/:na] Caused by: java.lang.NullPointerException: null at com.mysql.jdbc.ConnectionImpl.getServerCharacterEncoding(ConnectionImpl.java:3307) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1985) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1911) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506) ~[mysql-connector-java-5.1.30.jar:na] at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2344) ~[mysql-connector-java-5.1.30.jar:na] ... 57 common frames omitted 2018-12-14 21:31:03.969 WARN 30162 --- [ main] o.h.e.j.e.i.JdbcEnvironmentInitiator : HHH000342: Could not obtain connection to query metadata : Could not create connection to database server. Attempted reconnect 3 times. Giving up. 2018-12-14 21:31:03.975 WARN 30162 --- [ main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] 2018-12-14 21:31:03.979 INFO 30162 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2018-12-14 21:31:04.002 INFO 30162 --- [ main] utoConfigurationReportLoggingInitializer : Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled. 2018-12-14 21:31:04.009 ERROR 30162 --- [ main] o.s.boot.SpringApplication : Application startup failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE] at boss.portal.JwtAuthApplication.main(JwtAuthApplication.java:17) [classes/:na] Caused by: org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:264) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:228) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) ~[spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370) ~[spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359) ~[spring-orm-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE] ... 16 common frames omitted Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:100) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:54) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:137) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:254) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final] ... 32 common frames omitted