CalendarTest

package corejava;import java.text.DateFormatSymbols;import java.util.Calendar;import java.util.GregorianCalendar;import java.util.Locale;//import javax.crypto.spec.GCMParameterSpec;public class CalendarTest {public static void main(String[] args) {Locale.setDefault(Locale.ENGLISH);GregorianCalendar  d = new GregorianCalendar();int today =d.get(Calendar.DAY_OF_MONTH);int month =d.get(Calendar.MONTH);d.set(Calendar.DAY_OF_MONTH, 1);int weekday =d.get(Calendar.DAY_OF_WEEK);int firstOfWeek =d.getFirstDayOfWeek();int indent=0;while(weekday !=firstOfWeek){indent++;d.add(Calendar.DAY_OF_MONTH, -1);weekday =d.get(Calendar.DAY_OF_WEEK);}String[] weekNames = new DateFormatSymbols().getShortWeekdays();do{System.out.printf("%4s",weekNames[weekday]);d.add(Calendar.DAY_OF_MONTH, 1);weekday =d.get(Calendar.DAY_OF_WEEK);}while(weekday !=firstOfWeek);System.out.println();for(int i=1;i<=indent;i++)System.out.print("    ");d.set(Calendar.DAY_OF_MONTH, 1);do{int day =d.get(Calendar.DAY_OF_MONTH);System.out.printf("%3d",day);if(day==today) System.out.print("*");else System.out.print(" ");d.add(Calendar.DAY_OF_MONTH, 1);weekday =d.get(Calendar.DAY_OF_WEEK);if(weekday == firstOfWeek) System.out.println();}while(d.get(Calendar.MONTH)==month);if(weekday != firstOfWeek) System.out.println();}}