Design to implement Job Scheduling

Question

I am working on an application which needs scheduling (just like the one present in microsoft outlook meeting recurrence) feature. Where we can schedule the job daily, weekly, monthly and yearly and have variations under each schedule (e.g every second monday of month or every alternate monday of week etc).

It should basically work like it does in Microsoft Outlook meeting scheduling.

Any pointers, links, suggestions or any apis available that i could use to implement this logic will be of great help

Thanks

Answer 1

I recently worked on something similar, the main issue was finding the first day of the current week, from there it was relatively easy to find the day of the week required, and the other issue was finding the first day of the next month.

Here is the code to get

• start of the current week (current week's monday)
• start of next week (next monday)

• start of the next month (the 1st of the following month)

  import java.util.Calendar;
  import java.util.Date;
  
  // ... 
  
  public static long getWeekStart()
  {
      //INIT Date
      Calendar cal = Calendar.getInstance();
      cal.clear(Calendar.HOUR_OF_DAY);
      cal.clear(Calendar.MINUTE);
      cal.clear(Calendar.SECOND);
      cal.clear(Calendar.MILLISECOND);
  
      //get start of this week in milliseconds
      cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
      return cal.getTime().getTime();
  }
  
  public static long getNextWeek()
  {
      //INIT Date
      Calendar cal = Calendar.getInstance();
      cal.clear(Calendar.HOUR_OF_DAY);
      cal.clear(Calendar.MINUTE);
      cal.clear(Calendar.SECOND);
      cal.clear(Calendar.MILLISECOND);
  
      //get start of this week in milliseconds
      cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
  
      // start of the next week
      cal.add(Calendar.WEEK_OF_YEAR, 1);
      return cal.getTime().getTime();
  }
  
  public static long getNxtMonthStart()
  {
      Calendar cal = Calendar.getInstance();
      cal.clear(Calendar.HOUR_OF_DAY);
      cal.clear(Calendar.MINUTE);
      cal.clear(Calendar.SECOND);
      cal.clear(Calendar.MILLISECOND);
  
      // get start of the month
      cal.set(Calendar.DAY_OF_MONTH, 1);
  
      // get start of the next month
      cal.add(Calendar.MONTH, 1);
  
      return cal.getTime().getTime();
  }
  

Hope this helps with getting the days of the week.

Answer 2

You might want to have a look at Quartz