Main.java

/** GetWeeks
 *  Mattia Trombon
 *  
 *  Obtain all limit weeks from a period included between two dates
 */

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import org.joda.time.DateTime;

public class Main {
	
	static SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd"); 
	
	static Calendar start = Calendar.getInstance();
	static Calendar end = Calendar.getInstance();
	
	static Date tmp1;
	static Date tmp2;
	
	public static void main(String args[]) throws ParseException{
		
		/*
		Both arguments are mandatory. Earlier date as first argument, latest date as second.
		Please use yyyy-MM-dd format
		*/
		Date fromData = dt.parse(args[0]); 
		Date toData = dt.parse(args[1]); 
		
		start.setTime(fromData);
		end.setTime(toData);
		
		tmp1 = start.getTime();
		tmp2 = end.getTime();
		
		Calendar tmp3 = Calendar.getInstance();
		
		for (Date date = start.getTime(); 
				!start.after(end) || !start.after(tmp3); 
			 start.add(Calendar.DATE, 7), date = start.getTime()) {
				tmp3 = (Calendar) end.clone();
			    tmp3.add(Calendar.DATE, 7);
			    getWeekDays(date,start,tmp3);
		}
		
	}

	private static void getWeekDays(Date date, Calendar start1, Calendar end1) {
		Calendar cl = Calendar.getInstance();
		cl.setFirstDayOfWeek(Calendar.MONDAY);
	    cl.setTime(date);
	    
	    int week = cl.get(Calendar.WEEK_OF_YEAR);
	    
	    DateTime from =new DateTime(date);
	    DateTime onTheFirstDayOfTheFirstWeek = from.withWeekyear(from.getYear()).withWeekOfWeekyear(week).withDayOfWeek(1);
	    DateTime onTheLastDayOfTheFirstWeek = from.withWeekyear(from.getYear()).withWeekOfWeekyear(week).withDayOfWeek(7);
	    
	    if (onTheFirstDayOfTheFirstWeek.toDate().before(tmp1)){
	    	Date dateFrom = start.getTime();
	    	onTheFirstDayOfTheFirstWeek = new DateTime(dateFrom);
	    }
	    
	    if (onTheLastDayOfTheFirstWeek.toDate().after(tmp2)){
	    	Date dateTo = end.getTime();
	    	onTheLastDayOfTheFirstWeek = new DateTime(dateTo);
	    }
	    
	    if(onTheFirstDayOfTheFirstWeek.isAfter(onTheLastDayOfTheFirstWeek)){
	    	return;
	    }
	    
	    System.out.println(dt.format(onTheFirstDayOfTheFirstWeek.toDate()) + " - " + dt.format(onTheLastDayOfTheFirstWeek.toDate()) + "\n");
		
	}
}