报错信息

详细信息

ERROR [Druid-ConnectionPool-Create-2074541388] - create connection error, url:

jdbc:mysql://localhost:3306/ssmtest?characterEncoding=UTF-8, errorCode 0, state 08001
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create

connection to database server.
 at sun.reflect.GeneratedConstructorAccessor21.newInstance(Unknown Source)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
 at java.lang.reflect.Constructor.newInstance(Unknown Source)
 at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
 at com.mysql.jdbc.Util.getInstance(Util.java:386)
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
 at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2568)
 at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
 at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
 at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
 at sun.reflect.GeneratedConstructorAccessor18.newInstance(Unknown Source)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
 at java.lang.reflect.Constructor.newInstance(Unknown Source)
 at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
 at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
 at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
 at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection

(DruidAbstractDataSource.java:1408)
 at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection

(DruidAbstractDataSource.java:1464)
 at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run

(DruidDataSource.java:1995)
Caused by: java.lang.NullPointerException
 at com.mysql.jdbc.ConnectionImpl.getServerCharacterEncoding(ConnectionImpl.java:3279)
 at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1940)
 at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1866)
 at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1252)
 at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2486)
 at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
 ... 12 more

解决

这是因为本地的mysql安装的8.0，而项目所使用的驱动是5.1。

怎样确认？

首先查看本地mysql版本以及安装路径

打开桌面左下角搜索，输入mysql，找到mysql *.* Command Line Client,这里是mysql 8.0 Command Line Client，

可见是安装的mysql8.0

点击后输入密码再输入:

show variables like "%char%";

 

打开Maven项目目录下的pom.xml,找到mysql的驱动依赖

原来是5.1.26的版本，现在将其改为8.0.11

为什么是8.0.11

到maven的中央仓库中可以看到没有版本8.0.0

 

将pom.xml改过来之后，重启服务器即可。