您在正确的轨道上，但

• 如果使用 Integer 数组比使用 int 数组更好一个通用的 Comparator< Integer> 。


• 你必须使用 Arrays.sort Collections.sort 用于排序数组。



• 匿名内部类。

• You're better off with an Integer array than an int array if you're using a generic Comparator<Integer>.
• You have to use Arrays.sort instead Collections.sort for sorting an array.

• You have to make the distances variable final if it's referenced in an anonymous inner class.

final double[] distances=new double[]{3.2, 1.4, 7.3, 2.2, 9.1};
Integer[] sortedIDXs  = new Integer[]{0,1,2,3,4};
Arrays.sort(sortedIDXs, new Comparator<Integer>() {
    public int compare(Integer idx1, Integer idx2) {
        return Double.compare(distances[idx1], distances[idx2]);
    }
});