JDK8中好用的日期处理-LocalDate类-LocalTime-LocalDateTIme，mysql解决时区相差13小时的问题，日期格式器DateTimeFormatter
set global time_zone='+08:00';
set time_zone = '+08:00';show variables like '%time_zone:'
set global time_zone='+08:00';
set time_zone = '+08:00';show variables like '%time_zone:'