springboot连接mysql数据库发生异常：lower_case_table_names和PreparedStatement.isClosed()Z is abstract

												**springboot连接mysql数据库发生异常**

springboot版本 1.5.12
mysql 服务器版本 6.0.3
本地pom文件：

mysql
mysql-connector-java
5.1.46
runtime

在springboot连接mysql数据库时当驱动版本过高时报错如下：
2018-12-28 10:34:01.047 ERROR 10364 — [ main] o.a.tomcat.jdbc.pool.ConnectionPool : Unable to create initial connections of pool.

java.sql.SQLException: Unknown system variable ‘lower_case_table_names’
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2482) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2440) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1381) ~[mysql-connector-java-5.1.46.jar:5.1.46]
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3786) ~[mysql-connector-java-5.1.46.jar:5.1.46]

本地pom文件：

mysql
mysql-connector-java
5.0.8
runtime

在springboot连接mysql数据库时当驱动版本过低时报错如下：
2018-12-28 10:38:47.054 INFO 12200 — [ main] c.a.s.Springboot10CacheApplicationTests : Started Springboot10CacheApplicationTests in 7.015 seconds (JVM running for 9.39)

java.lang.AbstractMethodError: Method com/mysql/jdbc/PreparedStatement.isClosed()Z is abstract

at com.mysql.jdbc.PreparedStatement.isClosed(PreparedStatement.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:114)atcom.sun.proxy.$Proxy78.isClosed(Unknown Source)
at org.apache.ibatis.executor.BaseExecutor.closeStatement(BaseExecutor.java:285)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:65)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)atcom.sun.proxy.$Proxy69.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:83)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
at com.sun.proxy.$Proxy75.getEmployeeById(Unknown Source)
最后改成下面，成功查询到数据：

mysql
mysql-connector-java
5.1.21
runtime


总结：如果遇到类似的问题，需要找到适用于自己mysql服务版本的驱动，就可以解决问题了