Java中的C#IEnumerable

Question

我如何用java编写这个c#IEnumerable

    public class Generator
    {
        private char[] characters;

        public Generator(char[] characters)
        {
            this.characters = characters;
        }

        public IEnumerable<string> GetStrings(int totalDigit)
        {
            if (totalDigit > 0)
            {
                foreach (char c in characters)
                {
                    foreach (string next in GetStrings(totalDigit - 1))
                    {
                        yield return c + next;
                    }
                }
            }
            else
            {
                yield return string.Empty;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            int maxDigit = 2;
            char[] characters = "abc".ToCharArray();
            Generator generator = new Generator(characters);
            for (int i = 1; i <= maxDigit; i++)
            {
                Console.WriteLine(i +" Digit");
                foreach(string word in generator.GetStrings(i))
                {
                    Console.WriteLine(word);
                }
            }

        }
    }

输出

1 Digit
a
b
c
2 Digit
aa
ab
ac
ba
bb
bc
ca
cb
cc
Press any key to continue . . .

我试图用java制作单词列表生成器，但我无法用java编写这个c#enuable。 我尝试了很多阅读文档、教程、Q&；在java中使用iterable和迭代器，但仍然没有结果 我希望你能帮助我

谢谢