Java-7

public class TestEncryption {

         public static void main(String[] args) {

                  Scanner s = new Scanner(System.in);

                  System.out.print("请输入一个4位正整数：");

                  int num = s.nextInt();           

                 int bit4 = (num / 1000);

                  int bit3 = (num / 100) % 10;

                  int bit2 = (num / 10) % 10; 

                  int bit1 = num % 10; 

                  bit4 = (bit4+5)%10;

                  bit3 = (bit3+5)%10;

                  bit2 = (bit2+5)%10;

                  bit1 = (bit1+5)%10;

                  int  temp;

                  temp = bit4;

                  bit4 = bit1;

                  bit1 = temp;

                  temp = bit2;

                  bit2 = bit3;

                  bit3 = temp;

                  int ennum = bit4*1000+bit3*100+bit2*10+bit1;

                  System.out.println("加密后的数字为："+ennum);                 

         }

}