启动springboot报异常：java.sql.SQLException: Unknown system variable 'language' 解决方法

java.sql.SQLException: Unknown system variable 'language'
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2503) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1369) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3833) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3283) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2297) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:806) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_131]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_131]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_131]
	at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[na:1.8.0_131]
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328) ~[mysql-connector-java-5.1.40.jar:5.1.40]
	at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:732) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:664) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:479) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.(ConnectionPool.java:154) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.11.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.11.jar:na]
	at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:254) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:228) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111) [hibernate-core-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) [hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) [hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
	at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) [spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) [spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373) [spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362) [spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1081) [spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:856) [spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) [spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:372) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
	at cn.pp.springboot.Application.main(Application.java:12) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_131]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_131]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.4.4.RELEASE.jar:1.4.4.RELEASE]

估计是什么版本冲突，mysql-connector-java依赖包不加版本的话默认是5.1.4，然后报错了

		
			mysql
			mysql-connector-java
		

我指定相对低的版本就好了

                
			mysql
			mysql-connector-java
			5.1.24
		

至于为什么是 5.1.24 因为我的本地仓库里之前有下过，我就试着用了，然后就可以了