java使用冒泡排序引用类型的数组

 

TestDateSort.java

//对日期进行排序
public class TestDateSort {
	public static void main(String[] args) {
		//引用类型数组
		Date[] days = new Date[5];
		days[0] = new Date(2006, 5, 4);
		days[1] = new Date(2006, 7, 4);
		days[2] = new Date(2008, 5, 4);
		days[3] = new Date(2004, 5, 9);
		days[4] = new Date(2004, 5, 4);
		
		
		//冒泡排序
		bubbleSort(days);
		
		for(int i=0; i<days.length; i++) {
			//打印对象的引用，相当与直接调用toString(),需要重写toString()
			System.out.println(days[i]);
		}
		
	}
	
	//冒泡排序
	public static Date[] bubbleSort(Date[] a){
        int len = a.length;
		//从底往上
        for(int i = len-1;i>=1;i--){
			//数组序号从小到大
            for(int j = 0;j<=i-1;j++){
				//比较日期大小
                if(a[j].compare(a[j+1]) > 0){
					//下标值没变，指向的对象改变了
                    Date temp = a[j]; 
                    a[j]=a[j+1];
                    a[j+1]=temp;
                }
            }
        }
        return a;
    }
    
}

//定义日期类
class Date {
	int year, month, day;

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

	//比较日期大小
	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;
	}

	//重写toString()
	public String toString() {
		return "Year:Month:Day -- " + year + "-" + month + "-" + day;
	}
}

 

F:\java>javac TestDateSort.java

F:\java>java TestDateSort
Year:Month:Day -- 2004-5-4
Year:Month:Day -- 2004-5-9
Year:Month:Day -- 2006-5-4
Year:Month:Day -- 2006-7-4
Year:Month:Day -- 2008-5-4

F:\java>