解题思路:
1:将大写字母转化成小写字母,然后向后移一位,有两种思路:
第一种:将得到的字符加1然后转成字符串,最后将字符串转为成小写;

 char c = (char) ((chars[i]) + 1);
String s = String.valueOf(c).toLowerCase(Locale.ROOT);

第二种 将得到的字符-32直接得到小写的字符

 char c = (char) ((chars[i]) + 'b' - 'A');
  1. 将小写字母转化成相对应的数字
  2. 数字不变
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Locale;

/**
 * @author Administrator
 */
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        String str = null;

        if (null != (str = bf.readLine())) {
            char[] chars = str.toCharArray();
            for (int i = 0; i < chars.length; i++) {
                if ('A' <= chars[i] && chars[i] < 'Z') {
                    char c = (char) ((chars[i]) + 1);
                    String s = String.valueOf(c);
                    sb.append(s.toLowerCase(Locale.ROOT));
                }else if (chars[i] == 'Z') {
                    sb.append('a');
                }else if (chars[i] >= 'a' && chars[i] <= 'c'){
                    sb.append('2');
                }else if (chars[i] >= 'd' && chars[i] <= 'f'){
                    sb.append('3');
                }else if (chars[i] >= 'g' && chars[i] <= 'i'){
                    sb.append('4');
                }else if (chars[i] >= 'j' && chars[i] <= 'l'){
                    sb.append('5');
                }else if (chars[i] >= 'm' && chars[i] <= 'o'){
                    sb.append('6');
                }else if (chars[i] >= 'p' && chars[i] <= 's'){
                    sb.append('7');
                }else if (chars[i] >= 't' && chars[i] <= 'v'){
                    sb.append('8');
                }else if (chars[i] >= 'w' && chars[i] <= 'z'){
                    sb.append('9');
                }else {
                    sb.append(chars[i]);
                }
            }
        }
        System.out.println(sb.toString().trim());

//        dkgss87z9u52n9860pt96xsv9d9y5ox17861g6g67o2v87t
    }
}