背景知识:
我有一个运行在Tomcat 7上的Java 1.6 web应用程序。数据库为MySQL 5.5。之前，我使用Mysql JDBC驱动程序5.1.23连接到DB。一切工作。我最近升级到Mysql JDBC驱动程序5.1.33。升级后，Tomcat在启动应用程序时会抛出这个错误。
WARNING: Unexpected exception resolving reference
java.sql.SQLException: The server timezone value 'UTC' is unrecognized or represents
more than one timezone. You must configure either the server or JDBC driver (via
the serverTimezone configuration property) to use a more specifc timezone value if
you want to utilize timezone support.
为什么会这样?
当前回答
在我的例子中，它是一个测试环境，我必须让一个现有的应用程序在没有任何配置更改的情况下工作，如果可能的话，没有任何MySQL配置更改。 我能够通过遵循@vinnyjames的建议并将服务器时区更改为UTC来修复这个问题:
ln -sf /usr/share/zoneinfo/UTC /etc/localtime
service mysqld restart
这样做对我来说已经足够解决问题了。
其他回答
连接字符串应该像这样设置:
jdbc:mysql://localhost/db?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
如果你在xml文件(如persistence.xml, standalone-full.xml等)中定义连接，你应该使用&或者使用CDATA块。
在阅读了几篇关于这个主题的文章后，测试了不同的配置，并根据这个mysql bug线程的一些见解，我明白了:
the server time zone is important in particular to convert dates stored in the database to the time zone of the application server. there are other implications but this is the most noticeable one GMT x UTC time zone systems. GMT was conceived in the late 19th century and can be shifted between standard time and summer time. this property could lead to a situation where the database server shifts to summer time and the application doesn't notice it (perhaps there are other complications but I didn't research further). UTC does not vary over time (it is always within about 1 second of mean solar time at 0° longitude). serverTimeZone definition was introduced in mysql jdbc connectors versions 5.1 ahead. until version 8 it could be ignored with useLegacyDatetimeCode=true , which in conjunction with useJDBCCompliantTimezoneShift=true would make the application get the database time zone on every connection. In this mode GMT time zones such as 'British Summer Time' would be converted to the internal java/JDBC format. New time zones could be defined in a .properties file such as this one Starting with jdbc driver version 8, automatic time matching (useJDBCCompliantTimezoneShift) and legacy time format (useLegacyDatetimeCode) were removed (see mysql jdbc connector changelog). therefore setting these 2 parameters has no effect as they are completely ignored (new default is useLegacyDateTimeCode=false) In this manner setting serverTimezone became mandatory if any of the time zones (application/database servers) are not in the format 'UTC+xx' or 'GMT+xx' There is no impact of setting server time as UTC (for instance with jdbc:mysql://localhost:3306/myschema?serverTimezone=UTC, even if your application / database servers are not in this timezone. The important is for the application connection string + database to be synchronized with the same time zone. In different words, simply setting serverTimezone=UTC with a different time zone on the database server will shift any dates extracted from the database The MySQL default time zone can be set to UTC+0 with the my.ini or my.cnf files (windows / linux respectively) by adding the line default-time-zone='+00:00' (details in this StackOverflow post) Databases configured on AWS (amazon web services) are automatically assigned UTC+0 default time (see AWS help page here)
我解决了把下面的连接字符串在URL
jdbc:mysql://localhost:3306/db?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
我在[mysqld]部分添加了mysql配置文件 default_time_zone = ' + 03:00 ' 重启mysql服务器: Sudo服务mysql重启
其中+03:00我的UTC时区。
在我的操作系统ubuntu 16.04上配置文件的路径:
/etc/mysql/mysql.conf.d/mysqld.cnf
警告:如果你所在的时区有夏季和冬季时间。如果要更改时间，必须在配置中更改utc。一年两次(通常)或用sudo设置crontab。
我的url jdbc连接
"jdbc:mysql://localhost/java"
我也有同样的问题，我解决了它只附加”?serverTimezone=UTC"到我的字符串连接。
#我的问题是:
java.sql.SQLException:服务器时区值“CEST”无法识别或表示多个时区。如果希望利用时区支持，则必须配置服务器或JDBC驱动程序(通过serverTimezone配置属性)以使用更特定的时区值。
my dbDriver = com.mysql.jdbc.Driver
my jar = mysql-connector-java-8.0.12.jar
my java = 1.8
my tomcat = Apache Tomcat Version 8.5.32
my MySql server = MySql ver.8.0.12
