打印机补丁，输出字符串

应该如此吧，没有写输入的，自己写scanner

 // 输入字符串
        String str = "suH25";
        // 转换成char
        char[] charSr = str.toCharArray();
        int count = 0;
        // 判断小写字母转成大写，大写转小写
        for (int i = 0; i < charSr.length; i++) {
            if (Character.isLowerCase(charSr[i])) {
                charSr[i] = Character.toUpperCase(charSr[i]);
            } else{
                charSr[i] = Character.toLowerCase(charSr[i]);
            }
            if (charSr[i] >= 65 && charSr[i] <= 90 || charSr[i] >= 97 && charSr[i] <= 122 ){
                count++;
            }
        }
        System.out.println(String.valueOf(charSr));
        System.out.println(count);

public class Demo1 {
    public static void main(String[] args) {
        printChar("AZ12adf234ASF");

    }


    public static void printChar(String printStr) {
        char[] chars = printStr.toCharArray();
        String str = "";
        int j = 0;
        for (char aChar : chars) {
            int i = aChar;
            System.out.println(i);
            if (i > 96 && i < 123) {
                i -= 32;
                j++;
            } else if (i > 64 && i < 91) {
                i += 32;
                j++;
            }

            aChar = (char) i;
            str += aChar;
        }
        System.out.println(str);
        System.out.println(j);
    }
}