异常堆栈信息

Thu Dec 10 20:25:44 CST 2020 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
java.sql.SQLException: Unable to load authentication plugin 'caching_sha2_password'.
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:868)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:864)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1746)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2205)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2236)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2035)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    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:425)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
    at org.mybatis.generator.internal.db.ConnectionFactory.getConnection(ConnectionFactory.java:68)
    at org.mybatis.generator.config.Context.getConnection(Context.java:526)
    at org.mybatis.generator.config.Context.introspectTables(Context.java:436)
    at org.mybatis.generator.api.MyBatisGenerator.generate(MyBatisGenerator.java:222)
    at org.mybatis.generator.api.MyBatisGenerator.generate(MyBatisGenerator.java:133)
    at com.summer.mybatis.utils.UserGenerator.generator(UserGenerator.java:28)
    at com.summer.mybatis.utils.UserGenerator.main(UserGenerator.java:35)

保存原因分析

目前我所用的MySql 版本是：8.0.22，对应的 mysql-connector-java 版本为：5.1.41
因 MySql 8.x 的验证模块和5.x不同。

5.x版本是：default_authentication_plugin=mysql_native_password
8.x版本就是：default_authentication_plugin=caching_sha2_password

解决方案

1. 修改 mysql-connector-java 版本为 8.x
2. 重新安装5.x的 Mysql数据库