1
dbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested
原因是：客戶端不支持服務器請求的身份驗證協議； 考慮升級MySQL客戶端
查看本地的mysql的版本，看看是不是本地的是8.0結果jar還是5.0的
不一定是升級，降級也是有可能的
2
org.activiti.engine.ActivitiException: couldn't check if tables are already present using metadata:
### Error getting a new connection. Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
org.activiti.engine.ActivitiException：無法使用元數據檢查表是否已經存在：
###獲取新連接時出錯。 原因：com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：通信鏈接失敗
3
Cause: java.sql.SQLException: The server time zone value '�й���ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support
數據庫和系統時區差異造成
解決辦法：
在jdbc連接的url後面加上serverTimezone=GMT或者UTC參數即可。
4
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.apache.ibatis.reflection.Reflector (file:/G:/Maven/repository/org/mybatis/mybatis/3.2.5/mybatis-3.2.5.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.apache.ibatis.reflection.Reflector
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
idea的jdk版本過高，改爲1.8即可
5
Fri Jun 12 14:53:55 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.
添加（轉義）