Spring cron vs normal cron?

Question

I\'m trying to get a cron job working within a legacy Java/Spring/Hibernate project, so I decided to use the spring scheduler.

I want myTask.doStuff to run at 12:00

Answer 1

Taking some note from: https://www.baeldung.com/cron-expressions

A Spring Scheduled tasks is like this:

1 2 3 4 5 6 Index
- - - - - -
* * * * * * command to be executed
- - - - - -
| | | | | | 
| | | | | ------- Day of week (MON - SUN)
| | | | --------- Month (1 - 12)
| | | ----------- Day of month (1 - 31)
| |-------------- Hour (0 - 23)
| --------------- Minute (0 - 59)
----------------- Seconds (0 - 59)

From: https://www.cyberciti.biz/faq/how-do-i-add-jobs-to-cron-under-linux-or-unix-oses/

A Linux Cron job is like this:

1 2 3 4 5 Index
- - - - -
* * * * * command to be executed
- - - - -
| | | | |
| | | | ----- Day of week (0 - 7) (Sunday=0 or 7)
| | | ------- Month (1 - 12)
| | --------- Day of month (1 - 31)
| ----------- Hour (0 - 23)
------------- Minute (0 - 59)

Side note:

• Some article said it is possible to have a 7 optional param which is year , I have tried using latest spring and it show error, so I don't think it is working.
• If your Linux cron job expression is simple enough, seems like it is possible to just put an 0 in front and it will convert to the spring scheduled tasks expression
  • E.g. Every 5 minutes
    • */5 * * * * Linux cron job
    • 0 */5 * * * * Spring schedule tasks

Bonus: Spring Schedule Cron Generator

1. Click on Show code snippet
2. Click on Run Code snippet
3. Have fun!

$('.select2').select2({
  width: '100%'
});

//// Init ////////////
$dropdown = $("#secondsSelect");
for (let i = 1; i < 60; i++) {
  $dropdown.append($("").val(i).text(i));
}
$dropdown = $("#minSelect");
for (let i = 1; i < 60; i++) {
  $dropdown.append($("").val(i).text(i));
}
$dropdown = $("#hoursSelect");
for (let i = 1; i < 24; i++) {
  $dropdown.append($("").val(i).text(i));
}
$dropdown = $("#dayOfMonthSelect");
for (let i = 1; i < 32; i++) {
  $dropdown.append($("").val(i).text(i));
}
//// Init End ////////////


$('.select2').on('select2:select', function(e) {
  let value = e.params.data.id;
  let prevValue = $(this).val().length > 0 ? $(this).val()[0] : null;

  if (value != parseInt(value)) {
    $(this).val(value).change();
  } else if (prevValue != parseInt(prevValue)) {
    $(this).val(value).change();
  }
  calculateSpringCron();
});

let r = function(dropdown) {
  return dropdown.val().join(",");

}

let calculateSpringCron = function() {

  let result = [
    r($("#secondsSelect")),
    r($("#minSelect")),
    r($("#hoursSelect")),
    r($("#dayOfMonthSelect")),
    r($("#monthsSelect")),
    r($("#weekdaySelect")),
  ];

  $("#result").val(result.join(" "));

  $("#result-expand").html(result.join("    "))

}

calculateSpringCron();

.ms-container {
  display: flex;
  flex-direction: column;
  width: 100%;
  padding-left: 3em;
  padding-right: 3em;
  background: none !important;
  padding-bottom: 5em;
}

  

    
Spring Schedule Cron Generator
  


  

    Seconds:
    
      Every seconds
      Every even seconds
      Every odd seconds
      Every 5 seconds
      Every 10 seconds
      Every 15 seconds
      Every 30 seconds
    
  
  

    Minutes:
    
      Every minutes
      Every even minutes
      Every odd minutes
      Every 5 minutes
      Every 10 minutes
      Every 15 minutes
      Every 30 minutes
    
  
  

    Hours:
    
      Every hour
      Every even hour
      Every odd hour
      Every 3 hour
      Every 4 hour
      Every 6 hour
    
  






  

    Days of month:
    
      Every day of month
      Even day of month
      Odd day of month
      Every 5 days of month (5,10,15...)
      Every 10 days of month (10,20,30...)
    
  
  

    Months:
    
      Every month
      Even months
      Odd months
      Every 4 months
      Every 6 months(half year)
      Jan
      Feb
      Mar
      Apr
      May
      Jun
      Jul
      Aug
      Sep
      Oct
      Nov
      Dec
    
  
  

    Weekday:
    
      Every weekday
      Weekdays (MON-FRI)
      Weekend
      SUN
      MON
      TUE
      WED
      THU
      FRI
      MON
    
  


  

    Result:
     With a bit of seperation for better viewing: