密码翻译

这道题用到了java的 StringBuffer 类 

public StringBuffer append(String s)
将指定的字符串追加到此字符序列。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String str=br.readLine();
		StringBuffer sb = new StringBuffer();
		for(int i=0;i<str.length();i++) {
			if(str.charAt(i)>='A'&&str.charAt(i)<='Y') {
				sb.append((char)(str.charAt(i)+1));
			}
			else if(str.charAt(i)>='a'&&str.charAt(i)<='y') {
				sb.append((char)(str.charAt(i)+1));
			}
			else if(str.charAt(i)=='z') {
				sb.append('a');
			}
			else if(str.charAt(i)=='Z') {
				sb.append('Z');
			}
			else {
				sb.append(str.charAt(i));
			}
		}
		System.out.println(sb);
	}

}