java例程练习（对象类型数据的排序）

public class TestSort { public static void main(String[] args) { Date[] days = new Date[5]; days[0] = new Date(2004, 8, 6); days[1] = new Date(2007, 4, 6); days[2] = new Date(2007, 4, 9); days[3] = new Date(2004, 4, 6); days[4] = new Date(2004, 4, 5); bubbleSort(days); for(int i = 0; i < days.length; i++) { System.out.println(days[i]); } } public static Date[] bubbleSort(Date[] a) { int len = a.length; for(int i = len - 1; i >= 1; i--) { for(int j = 0; j <= i -1; j++) { if(a[j].compare(a[j + 1]) > 0) { Date temp = a[j]; a[j] = a[j + 1]; a[j + 1] = temp; } } } return a; } } class Date { int year; int month; int 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 String toString() { return "" + year + "-" + month + "-" + day; } }