字符串排序

方法1：直接用数组排序

public class StringSort {
    public static void main(String[] args) {
        String[] strings = {"abc123", "abc+1234", "ababab--1"};

        // 对每个字符串计算字母字符个数和数字字符个数，并按照字母数字比和字符串本身大小排序
        Arrays.sort(strings, (s1, s2) -> {
            int alphaCount1 = 0, numericCount1 = 0;
            for (char c : s1.toCharArray()) {
                if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z') alphaCount1++;
                else if (c >= '0' && c <= '9') numericCount1++;
            }
            double ratio1 = numericCount1 == 0 ? Double.MAX_VALUE : (double) alphaCount1 / numericCount1;

            int alphaCount2 = 0, numericCount2 = 0;
            for (char c : s2.toCharArray()) {
                if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z') alphaCount2++;
                else if (c >= '0' && c <= '9') numericCount2++;
            }
            double ratio2 = numericCount2 == 0 ? Double.MAX_VALUE : (double) alphaCount2 / numericCount2;

            if (ratio1 < ratio2) return 1;
            else if (ratio1 > ratio2) return -1;
            else return s2.compareTo(s1); // 按照降序排列
        });

        // 输出排序后的结果
        System.out.println(Arrays.toString(strings));
    }
}

方法二:用Collections进行排序