com.mysql.jdbc.exceptions.jdbc4.MySQLNonTrans。。。

引⾔

台式机安装的 mysql 是8.0版本，今天重新下载了 jeecg3.7，导⼊数据库⽂件，项⽬启动时报如下错误。

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 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:919) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:862)

at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2331) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2084) at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:795) at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:44) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 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:142) at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:211)

at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:136)

at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1271) at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1325) at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:1215)Caused by: java.lang.NullPointerException

解决步骤

⽅法就是，将驱动版本修改为与连接的数据库版本保持⼀致。

1、修改数据库连接信息，添加时区信息

然鹅，并没起效。

2、修改mysql驱动版本，数据库版本和驱动版本保持⼀致

执⾏的sql⽂件中 mysql 版本是5.0，数据库版本是8.0，修改 pom ⽂件中 mysql 驱动版本，5.0 修改为 8.0。 ok了。