Java根据正整数的位数并逆序打印出各位数字

import java.util.Scanner;public class Ex24 {public static void main(String[] args) {  Ex24 tn = new Ex24();  Scanner s = new Scanner(System.in);  long a = s.nextLong();  if(a < 0 || a > 100000) {  System.out.println("Error Input, please run this program Again");  System.exit(0);  }  if(a >=0 && a <=9) {  System.out.println( a + "是一位数");  System.out.println("按逆序输出是" + '/n' + a);  } else if(a >= 10 && a <= 99) {  System.out.println(a + "是二位数");  System.out.println("按逆序输出是" );  tn.converse(a);  } else if(a >= 100 && a <= 999) {  System.out.println(a + "是三位数");  System.out.println("按逆序输出是" );  tn.converse(a);  } else if(a >= 1000 && a <= 9999) {  System.out.println(a + "是四位数");  System.out.println("按逆序输出是" );  tn.converse(a);  } else if(a >= 10000 && a <= 99999) {  System.out.println(a + "是五位数");  System.out.println("按逆序输出是" );  tn.converse(a);  }}public void converse(long l) {  String s = Long.toString(l);  char[] ch = s.toCharArray();  for(int i=ch.length-1; i>=0; i--) {  System.out.print(ch[i]);  }}}