public static void bubbleSort(Date[] days) {
  int len = days.length;
  Date temp;
  for (int i = len - 1; i >= 1; i--) {
   for (int j = 0; j < i; j++) {
    if (days[j].compare(days[j + 1]) > 0) {
     temp = days[j + 1];
     days[j + 1] = days[j];
     days[j] = temp;
    }
   }
  }
 }
class Date {
 int year, month, day;

 Date(int y, int m, int d) {
  year = y;
  month = m;
  day = d;
 }

 public int compare(Date date) {
  return year > date.year ? 1 : year < date.year ? -1
    : month > date.month ? 1 : month < date.month ? -1
      : day > date.day ? 1 : day < date.day ? -1 : 0;
 }

 public void print() {
  System.out.println(year + " " + month + " " + day);
 }
}

package testSortAlgorithm;

public class BubbleSort {
 public static void main(String[] args) {
  int array[] = { 5, 6, 8, 4, 2, 4, 9, 0 };
  bubbleSort(array);
  for (int i = 0; i < array.length; i++) {
   System.out.println(array[i]);
  }
 }

 public static void bubbleSort(int array[]) {
  int temp;
  for (int i = array.length - 1; i > 0; i--) {
   for (int j = 0; j < i; j++) {
    if (array[j] > array[j + 1]) {
     temp = array[j];
     array[j] = array[j + 1];
     array[j + 1] = temp;
    }
   }
  }
 }
}