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  • com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException问题解决

    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.<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(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。

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  • 原文地址:https://www.cnblogs.com/yadongliang/p/12359320.html
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