对包含Java中的数字的字符串进行排序 [英] Sorting Strings that contains number in Java

问题描述

我对字符串的默认比较器（在SortedSet中）有问题。问题是默认比较器没有排序包含数字的好字符串，即：
在集合中我有：

I have problem with default comparator for Strings (in SortedSet). The problem is that default comparator doesn't sort good String that contains numbers i.e.: In set i have:

room1, room2, room100

自然顺序应该如上所述，但是我有以下内容：

Natural ordering should be like above but in set I have:

room1, room100, room2

我知道它为什么但我不知道如何更改它。

I know why it is but I don't know how to change it.

推荐答案

试试这个比较器，删除所有非数字字符，然后将剩余字符作为数字进行比较：

Try this comparator, which removes all non-digit characters then compares the remaining characters as numbers:

Collections.sort(strings, new Comparator<String>() {
    public int compare(String o1, String o2) {
        return extractInt(o1) - extractInt(o2);
    }

    int extractInt(String s) {
        String num = s.replaceAll("\\D", "");
        // return 0 if no digits found
        return num.isEmpty() ? 0 : Integer.parseInt(num);
    }
});

这是一个测试：

public static void main(String[] args) throws IOException {
    List<String> strings = Arrays.asList("room1", "foo", "room2", "room100", "room10");
    Collections.sort(strings, new Comparator<String>() {
        public int compare(String o1, String o2) {
            return extractInt(o1) - extractInt(o2);
        }

        int extractInt(String s) {
            String num = s.replaceAll("\\D", "");
            // return 0 if no digits found
            return num.isEmpty() ? 0 : Integer.parseInt(num);
        }
    });
    System.out.println(strings);
}

输出：

[foo, room1, room2, room10, room100]

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