1、官网API https://knowm.org/javadocs/sundial/org/quartz/triggers/CronExpression.html 2、判断时间是否匹配该表达式 https://www.jianshu.com/p/7a11f2b33c26 3、cron表达式详解 https://www.cnblogs.com/javahr/p/8318728.html
