Java输入一个字母，输出其前后的字母

import java.util.*;class Test{ public static void main(String[] args) {  Scanner x=new Scanner(System.in);  char a=x.nextchar();if(a>='a'&&a<'z')    System.out.print(a-1);    System.out.print(a);    System.out.print(a+1); else if(a=='z')    System.out.print(a-1);    System.out.print(a);    System.out.print("a"); if(a>='A'&&a<'Z')    System.out.print(a-1);    System.out.print(a);    System.out.print(a+1); else if(a=='Z')    System.out.print(a-1);    System.out.print(a);    System.out.print("A"); else     System.out.println("输入不正确"); } }