Java date plus one year, in January, a week, a day

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
 
public class Test {
    public static void main(String[] args) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = new Date();

        Sdf.format stringDate = String (DATE);
        System.out.println (stringDate);
 
        Calendar Calendar the GregorianCalendar new new = ();
        calendar.setTime (DATE);
        Calendar.add (Calendar.YEAR,. 1); // put to date after increasing year, year negative Save
        dATE = calendar.getTime ();
        stringDate = sdf.format (dATE);
        System.out.println (stringDate);
 
        Calendar.add (the Calendar.MONTH,. 1); // the date additional month later, a negative month Save
        DATE = calendar.getTime ();
        stringDate = sdf.format (DATE);
        System.out.println (stringDate);
 
        Calendar.add (Calendar.WEEK_OF_MONTH,. 1); // put additional week later date, a negative one week Save
        dATE = calendar.getTime ();
        stringDate = sdf.format (dATE);
        System.out.println (stringDate);
 
        Calendar.add (Calendar.DAY_OF_MONTH,. 1); // add a day to the next date, a negative one day Save
        DATE = calendar.getTime ();
        stringDate = sdf.format (DATE);
        the System .out.println (stringDate);
    }
}