参考文章：https://blog.csdn.net/weixin_37577564/article/details/80329775
在JDBC使用的时候有时候会出现java.sql.SQLException: The server time zone value '???ú±ê×??±??' is unrecognized or represents........的错误，具体错误如下：
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
java.sql.SQLException: The server time zone value '???ú±ê×??±??' 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.
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:127)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:95)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:87)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:61)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:71)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:76)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:862)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:444)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:230)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:226)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at zhu.jdbc.unit.UnitMysql.getConnection(UnitMysql.java:34)
at zhu.jdbc.dao.imp.ITb_UserImpI.insertData(ITb_UserImpI.java:55)
at zhu.jdbc.dao.imp.ITb_UserImpI.insertData(ITb_UserImpI.java:1)
at zhu.jdbc.service.imp.ITb_UserServiceImpI.insertData(ITb_UserServiceImpI.java:35)
at zhu.jdbc.service.imp.ITb_UserServiceImpI.insertData(ITb_UserServiceImpI.java:1)
at zhu.jdbc.servlet.Servlet_TbUser.Insert(Servlet_TbUser.java:87)
at zhu.jdbc.servlet.Servlet_TbUser.doPost(Servlet_TbUser.java:41)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value '???ú±ê×??±??' 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.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:59)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:83)
at com.mysql.cj.util.TimeUtil.getCanonicalTimezone(TimeUtil.java:128)
at com.mysql.cj.protocol.a.NativeProtocol.configureTimezone(NativeProtocol.java:2201)
at com.mysql.cj.protocol.a.NativeProtocol.initServerSession(NativeProtocol.java:2225)
at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:1391)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:993)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:852)
... 36 more
五月 15, 2018 9:38:04 下午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [Servlet_TbUser] in context with path [/myweb2] threw exception
java.lang.NullPointerException
at zhu.jdbc.dao.imp.ITb_UserImpI.insertData(ITb_UserImpI.java:59)
at zhu.jdbc.dao.imp.ITb_UserImpI.insertData(ITb_UserImpI.java:1)
at zhu.jdbc.service.imp.ITb_UserServiceImpI.insertData(ITb_UserServiceImpI.java:35)
at zhu.jdbc.service.imp.ITb_UserServiceImpI.insertData(ITb_UserServiceImpI.java:1)
at zhu.jdbc.servlet.Servlet_TbUser.Insert(Servlet_TbUser.java:87)
at zhu.jdbc.servlet.Servlet_TbUser.doPost(Servlet_TbUser.java:41)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)解决办法
这里其实报告了一个警告和一个错误。
第一行的警告是因为我们一直用的驱动类 com.mysql.jdbc.Driver 已经过时了，虽然还能用，但是会报警告信息。警告信息中也已经告诉了我们新的驱动类，如下：
com.mysql.cj.jdbc.Driver这样这里就不会报警告了。
剩下的就是错误信息了，就是下面很长很长的，看着很唬人
出现这个的原因是因为 mysql返回的时间总是有问题，比实际时间要早8小时。
//将连接mysql的url后加上serverTimezone=GMT%2B8，表示使用东八区时间
public static final String URL="jdbc:mysql://localhost:3306/jdbc01?characterEncoding=utf8&serverTimezone=GMT%2B8";在JDBC连接的url后面加上serverTimezone=GMT即可解决问题，如果需要使用GMT+8时区，需要写成GMT%2B8。
问题解决！