Question

我建立了一对夫妇：

public class Couple<E,K> {
    E first;    K second;

    Couple(E first, K second){
        this.first = first;
        this.second = second;
    }
    public E getFirst(){
        return first;
    }
    public K getSecond(){
        return second;
    }
}

ArrayList<Couple<String, Integer>>

ArrayList<Couple<URL, Integer>> a = ArrayList<Couple<URL, Integer>>();
a=fillArray();

我想通过整数的第二个元素的值来排序'a'。

Answer 1

这样做

您的SimpleComparator

class SimpleComparator implements Comparator<Couple<URL, Integer>> {
    public int compare(Couple<URL, Integer> a, Couple<URL, Integer> b) {
        return a.second.compareTo(b.second); 
    }
}

你的排序

Collections.sort(a,new SimpleComparator()); // now a is sorted based on second value.

Answer 2

a.sort(new Comparator<Couple<URL, Integer>>() {
    public int compare(Couple<URL, Integer> a, Couple<URL, Integer> b) {
        return a.second.compareTo(b.second); //assuming a.second is not null
    }
});

对复杂类型的ArrayList进行排序

2 个答案: