时区错误
报错信息：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.
解决：把配置文件改为URL=jdbc:mysql://localhost:3306/elm?characterEncoding=utf-8&serverTimezone=CTT
@Override注解报红出现Undo Set language level to 6 - @Override in interfaces?
该问题的原因是java工程JDK的Language level 版本过低导致，@oveeide注解是在jdk6之后出来的，而我的工程中module中jdk Language level 用的是5，因此报红。
Information:javac 1.8.0_181 was used to compile java sources
报错原因：因为Idea中已经配置了jdk 1.8.0_181的版本，但Idea有几个地方的jdk版本被默认为1.6版本的jdk。
解决：
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以下的全都要一致，均为1.8
连接数据库出现问题
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
Caused by: javax.net.ssl.SSLException: Software caused connection abort: recv failed
Suppressed: java.net.SocketException: Software caused connection abort: socket write error
解决：
在配置文件的URL结尾加上 &autoReconnect=true
即URL=jdbc:mysql://localhost:3306/elm?characterEncoding=utf-8&serverTimezone=CTT&autoReconnect=true
报告SQL语法错误
java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selet * from admin where adminName='wanglei' and password='123'' at line 1
错误 selet * from admin where adminName='wanglei' and password='123'
正确 select * from admin where adminName='wanglei' and password='123'