import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;public class HashtableDemo {public static void main(String args[]) throws AssertionError, ParseException {DateFormat df = new SimpleDateFormat("dd-MM-yyyy");//comparing date using compareTo method in JavaSystem.out.println("Comparing two Date in Java using CompareTo method");compareDatesByCompareTo(df, df.parse("01-01-2012"), df.parse("01-01-2012"));compareDatesByCompareTo(df, df.parse("02-03-2012"), df.parse("04-05-2012"));compareDatesByCompareTo(df, df.parse("02-03-2012"), df.parse("01-02-2012"));//comparing dates in java using Date.before, Date.after and Date.equalsSystem.out.println("Comparing two Date in Java using Date's before, after and equals method");compareDatesByDateMethods(df, df.parse("01-01-2012"), df.parse("01-01-2012"));compareDatesByDateMethods(df, df.parse("02-03-2012"), df.parse("04-05-2012"));compareDatesByDateMethods(df, df.parse("02-03-2012"), df.parse("01-02-2012"));//comparing dates in java using Calendar.before(), Calendar.after and Calendar.equals()System.out.println("Comparing two Date in Java using Calendar's before, after and equals method");compareDatesByCalendarMethods(df, df.parse("01-01-2012"), df.parse("01-01-2012"));compareDatesByCalendarMethods(df, df.parse("02-03-2012"), df.parse("04-05-2012"));compareDatesByCalendarMethods(df, df.parse("02-03-2012"), df.parse("01-02-2012"));}public static void compareDatesByCompareTo(DateFormat df, Date oldDate, Date newDate) {//how to check if date1 is equal to date2if (oldDate.compareTo(newDate) == 0) {System.out.println(df.format(oldDate) + " and " + df.format(newDate) + " are equal to each other");}//checking if date1 is less than date 2if (oldDate.compareTo(newDate) < 0) {System.out.println(df.format(oldDate) + " is less than " + df.format(newDate));}//how to check if date1 is greater than date2 in javaif (oldDate.compareTo(newDate) > 0) {System.out.println(df.format(oldDate) + " is greater than " + df.format(newDate));}}public static void compareDatesByDateMethods(DateFormat df, Date oldDate, Date newDate) {//how to check if two dates are equals in javaif (oldDate.equals(newDate)) {System.out.println(df.format(oldDate) + " and " + df.format(newDate) + " are equal to each other");}//checking if date1 comes before date2if (oldDate.before(newDate)) {System.out.println(df.format(oldDate) + " comes before " + df.format(newDate));}//checking if date1 comes after date2if (oldDate.after(newDate)) {System.out.println(df.format(oldDate) + " comes after " + df.format(newDate));}}public static void compareDatesByCalendarMethods(DateFormat df, Date oldDate, Date newDate) {//creating calendar instances for date comparisionCalendar oldCal = Calendar.getInstance();Calendar newCal = Calendar.getInstance();oldCal.setTime(oldDate);newCal.setTime(newDate);//how to check if two dates are equals in java using Calendarif (oldCal.equals(newCal)) {System.out.println(df.format(oldDate) + " and " + df.format(newDate) + " are equal to each other");}//how to check if one date comes before another using Calendarif (oldCal.before(newCal)) {System.out.println(df.format(oldDate) + " comes before " + df.format(newDate));}//how to check if one date comes after another using Calendarif (oldCal.after(newCal)) {System.out.println(df.format(oldDate) + " comes after " + df.format(newDate));}}
}