在Java中的属性值排序的对象的ArrayList [英] Sorting an object ArrayList by an attribute value in Java

问题描述

我 ArrayList的僵尸，其中填充有名为僵尸的对象。 僵尸的属性健康， X ，是。 僵尸，这是设置的我怎么会以升序排序的数组，使用属性 X 最初具有随机值？

I have ArrayList zombie, which is populated with an object called Zombie. Zombie has the attributes health, x, y. How would I sort the array in ascending order, using the attribute x of Zombie, which is set to initially have random values?

我已经找到了一个可能的<一个href=\"http://stackoverflow.com/questions/4310014/sort-an-arraylist-base-on-multiple-attributes\">solution我的问题，但我不知道答案的语法。并解释说，答案可能会有帮助，也。

I have already found a possible solution to my problem, but I do not understand the syntax of the answer. Explaining that answer may help, also.

推荐答案

您想要使用<一个href=\"http://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#sort%28java.util.List,%20java.util.Comparator%29\"><$c$c>Collections.sort用自定义<连词href=\"http://docs.oracle.com/javase/7/docs/api/java/util/Comparator.html\"><$c$c>Comparator.

Collections.sort(list, new Comparator<Zombie>() {
    @Override
    public int compare(Zombie z1, Zombie z2) {
        if (z1.x() > z2.x())
            return 1;
        if (z1.x() < z2.x())
            return -1;
        return 0;
    }
});

从本质上讲，比较是如何表示的列表应该通过它的比较方法进行排序的关键。随着比较上面，我们考虑 Z1 是大于的比 Z2 如果 Z1 具有较高的 X 值（我们通过返回显示此 1 ）。在此基础上，我们的排序列表。

Essentially, a Comparator is a key that signifies how a list should be ordered via its compare method. With the Comparator above, we consider z1 to be greater than z2 if z1 has the higher x value (and we show this by returning 1). Based on this, we sort list.

这篇关于在Java中的属性值排序的对象的ArrayList的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！