用Java语言写出输入为123输出为壹贰叁

好的，这个问题可以采用Java语言的字符串和数组处理。以下是示例代码：

public class JavaNumberToChinese {

    private static final String[] CHINESE_NUMBER = {"零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖"};
    private static final String[] CHINESE_UNIT = {"", "拾", "佰", "仟"};

    public static String numberToChinese(String input) {
        if (input == null || input.isEmpty()) {
            return "";
        }

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < input.length(); i++) {
            int num = input.charAt(i) - '0';
            if (num < 0 || num > 9) {
                return "";
            }

            if (i != 0) {
                sb.append(CHINESE_UNIT[input.length() - i - 1]);
            }

            sb.append(CHINESE_NUMBER[num]);
        }

        return sb.toString();
    }

    public static void main(String[] args) {
        String input = "123";
        String output = numberToChinese(input);
        System.out.println(output); // 壹贰叁
    }
}