错误：

mysql Client does not support authentication protocol requested by server; consider upgrading MySQL client。

原因：高版本mysql 8.0引入安全认证机制，但程序还是使用低版本认证方式。

解决办法：

#先登录：mysql -u root -p

#接着输入你的密码

解决：修改用户表，增加mysql_native_password 显式说明，注意在密码和用户、主机处加单引号。

ALTER USER root@% IDENTIFIED WITH mysql_native_password BY 你的密码;

ALTER USER root@localhost IDENTIFIED WITH mysql_native_password BY 你的密码;

SELECT plugin FROM mysql.user WHERE User =root;

error log:
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:921)
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870)
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:812)
 at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3269)
 at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1182)
 at com.mysql.jdbc.Connection.createNewIO(Connection.java:2644)
 at com.mysql.jdbc.Connection.<init>(Connection.java:1531)
 at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
 at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
 at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
 at cn.com.talented.connection.MysqlConnection.getConnection(MysqlConnection.java:27)

来源参考:
https://blog.csdn.net/qq_19707521/article/details/80226321