Java loop extracting month and year between two dates

Question

I have a ContratMercan with 2 Timestamps containing start and end dates. I have to create a new entity SeguimientoSeccion for each month between this 2 dates.

I have 2 questions:

• There is a way to improve it?
• After this I will need to manipulate the List<SeguimientoSeccion> secciones to see which one matches other entity... I though about making a Map but there can be 2 or more sections in each month and year

private List<SeguimientoSeccion> createSectionsPerMonth(ContratMercan contrato) { List<SeguimientoSeccion> secciones = new ArrayList<SeguimientoSeccion>(); Calendar start = Calendar.getInstance(); start.setTime(contrato.getPeriodoEntregaIni()); start.set(Calendar.DAY_OF_MONTH, 1); Calendar end = Calendar.getInstance(); end.setTime(contrato.getPeriodoEntregaFin()); end.set(Calendar.DAY_OF_MONTH, 2); // for loop comparison for (int month = start.get(Calendar.MONTH), year = start.get(Calendar.YEAR); start.before(end); month = start.get(Calendar.MONTH), year = start.get(Calendar.YEAR)) { SeguimientoSeccion seccion = new SeguimientoSeccion(); seccion.setMonth(month + 1); // natural month number seccion.setYear(year); start.add(Calendar.MONTH, 1); secciones.add(seccion); } return secciones; } 

Answer 1

The code would be simpler if you used a Calendar object as the loop variable.

Calendar current = …; Calendar end = …; for (; current.before(end); current.add(Calendar.MONTH, 1)) { SeguimientoSeccion seccion = new SeguimientoSeccion(); seccion.setMonth(1 + current.get(Calendar.MONTH)); // natural month number seccion.setYear(current.get(Calendar.YEAR)); secciones.add(seccion); } 

Consider implementing a SeguimientoSeccion.setMonthYear(m, y) method instead, as it's probably useless to set one of the fields without also setting the other.