JAVA中根据集合中对象属性排序的方法

package Collection;

import java.util.*;

public class Sort {
    private static ArrayList list = new ArrayList();
    private static UserBean[] user = new UserBean[4];

    public static void main(String[] args) {
        Sort sort = new Sort();
        user[0] = new UserBean("004",34);
        user[1] = new UserBean("003",56);
        user[2] = new UserBean("010",1);
        user[3] = new UserBean("002",22);

        for (int i = 0; i < 4; i++) {
            list.add(user[i]);
        }
        //arg1排序列表，arg2列表顺序比较器为null时使用自然排序
        Collections.sort(list,new ReverseSort());

        //arg1排序列表，arg2改变列表的随机源
        //Collections.shuffle(list,new Random());

        for (Iterator iterator = list.listIterator();iterator.hasNext()) {
            System.out.println(((UserBean)iterator.next()).name);
        }
    }
}

class UserBean implements Comparable{
    public String name;
    public int age;

    public UserBean(String name,int age) {
        this.name = name;
        this.age = age;
    }

    //类对象属性进行比较时，继承一个自然排序接口，重写一个自然比较方法
    public int compareTo(Object obj) {
        UserBean user = (UserBean)obj;
        return this.name.compareTo(user.name);
    }
}

//自定义反向排序比较器
class ReverseSort implements Comparator{

    public int compare(Object obj1,Object obj2) {
        UserBean user1 = (UserBean)obj1;
        UserBean user2 = (UserBean)obj2;
        return -user1.name.compareTo(user2.name);
    }
}

评论

2 楼 qiu768 2008-11-05  

非常感谢，帮了我一个大忙！！再谢！

1 楼 cn_arthurs 2008-10-08  

顶个