同时对两个arrayLists进行排序

Question

假设我有两个ArrayLists:

name: [Four, Three, One, Two]
num:  [4, 3, 1, 2]

如果我这样做:Arrays.sort(num),那么我有:

name: [Four, Three, One, Two]
num:  [1, 2, 3, 4]

有没有什么方法可以对num进行排序并将其反映在名称中,这样我最终可能会:

name: [One, Two, Three, Four]
num:  [1, 2, 3, 4]

？请帮帮我.我想到了比较器和对象,但根本不知道它们.

Answer 1

您应该以某种方式将字段和字段关联 到一个类中,然后具有该特定类的实例列表.在此类中,提供检查数值的方法.如果对实例进行排序,那么名称字段也将按您所希望的顺序排列.namenumcompareTo()

class Entity implements Comparable<Entity> {
    String name;
    int num;
    Entity(String name, int num) {
        this.name = name;
        this.num = num;
    }
    @Override
    public int compareTo(Entity o) {
        if (this.num > o.num)
            return 1;
        else if (this.num < o.num)
            return -1;
        return 0;
    }
}

测试代码可能是这样的:

public static void main(String[] args) {
    List<Entity> entities = new ArrayList<Entity>();
    entities.add(new Entity("One", 1));
    entities.add(new Entity("Two", 2));
    entities.add(new Entity("Three", 3));
    entities.add(new Entity("Four", 4));
    Collections.sort(entities);

    for (Entity entity : entities)
        System.out.print(entity.num + " => " + entity.name + " ");
}

输出:

1 => 1 2 => 2 3 => 3 4 => 4