What is the meaning/frequency of this Quartz Cron Expression?

Question

What is the frequency of this value defined in Quartz API?

I have seen the following definition in applicationContext.xml

<value>0 * * * * ?</value>

Answer 1

This will execute the task every month , every day at every hour at every minute , at second 0 . For example, it will be executed on:

21 November 2013, at 17:00:00
21 November 2013, at 17:01:00
21 November 2013, at 17:02:00

but it won't be executed on:

21 November 2013, at 17:00:01

What does the definition in the application.xml mean ?

<value>0       *      *         *        *          ?      </value>
       ^       ^      ^         ^        ^          ^
    second  minute   hour  day-of-month  month  day-of-week

Note that the * sign means every , while the ? character is allowed for the day-of-month and day-of-week fields. It is used to specify no specific value .

More info:

• Quartz scheduler CronTrigger