Java Collection.sort 排序升序, 降序问题

不多说，记住2点, 直接上代码(下面是降序):

 

package mall;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class TestSort2 {
    public static void main(String[] args) {
        List<Test> list = new ArrayList<Test>();
        
        String [] n = {"a", "b", "c", "d", "e", "f", "g" , "h" , "i", "j", "k"};
        double [] d = {0, 0, 34581, 0, 22017, 20807, 0 , 0 , 20443.2, 44457,0};
        double [] a = {400, 0, 400, 200, 150, 400, 600, 300, 200, 500, 0};
        for (int i = 0; i < a.length; i++) {
            Test s = new Test(n[i], d[i], a[i]);
            list.add(s);
        }
        
        //假如A的值大于B，你返回1 ,这样调用Collections.sort()方法就是升序
        //假如A的值大于B，你返回-1,这样调用Collections.sort()方法就是降序
        Collections.sort(list, new Comparator<Test>() {
            //总销售额(大->小)
            public int compare(Test o1, Test o2) {
                if(o1.getTotalPrice().compareTo(o2.getTotalPrice()) == 1)
                    return -1;
                return 0;
            }
        });
        
        for (int i = 0; i < list.size(); i++) {
            Test s = list.get(i);
            System.out.println("价格:"+s.getTotalPrice() + " , 面积:" + s.getArea());
        }
    }
    
    static class Test {
        private String name;
        private Double totalPrice;
        private Double area;
        
        public Test(String name, double totalPrice, double area){
            this.name = name;
            this.totalPrice = totalPrice;
            this.area = area;
        }
        
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public Double getTotalPrice() {
            return totalPrice;
        }
        public void setTotalPrice(Double totalPrice) {
            this.totalPrice = totalPrice;
        }
        public Double getArea() {
            return area;
        }
        public void setArea(Double area) {
            this.area = area;
        }
        
    }
}