把数字翻译成字符串（Java实现）

public class E46Translation {
    //计算数字的翻译方式，1-'a'... 25-'z'

    public static int getTranslationCount(int number) {
        if (number < 0)
            return -1;

        char[] numbers = String.valueOf(number).toCharArray();
        return getTranslationCount(numbers);
    }

    private static int getTranslationCount(char[] numbers) {
        int length = numbers.length;
        //count[i]记录以第i个数字开头字段的翻译方式数量
        int[] counts = new int[length];
        for (int i = length - 1; i >= 0; i--) {
            int count = 0;
            //0-9数字的翻译方式计算
            if (i < length - 1)
                count += counts[i + 1];
            else
                count += 1;
            //10-25数字的翻译方式计算
            if (i < length - 1) {
                int sum = Integer.valueOf(numbers[i] + String.valueOf(numbers[i + 1]));
                if (sum >= 10 && sum <= 25) {
                    if (i < length - 2)
                        count += counts[i + 2];
                    else
                        count += 1;
                }
            }
            counts[i] = count;
        }

        return counts[0];
    }

    //测试用例
    public static void main(String[] args) {
        int number = 12258;
        System.out.println(E46Translation.getTranslationCount(number));  //5
    }
}