Armstrong number or not in Java

import java.io.*;

class Armstrong{
      public static void main(String args[]){
try{
  BufferedReader object = new BufferedReader(new InputStreamReader(System.in));
  System.out.println("Enter number");
  int num= Integer.parseInt(object.readLine());
  int n = num; 
  int check=0,remainder;
  while(num > 0){
  remainder = num % 10;
  check = check + (int)Math.pow(remainder,3);
  num = num / 10;
  }
  if(check == n)
  System.out.println(n+" is an Armstrong Number");
  else
  System.out.println(n+" is not a Armstrong Number");
}
  catch(Exception e){
  System.out.println("Out of range!");
  }
   }
}

Example :

Input – 153

Output - 153 is Armstrong Number

String Palindrome or not

import java.io.*;

public class Palindrome  {
  public static void main(String [] args){
  try{
  BufferedReader object = new BufferedReader(new InputStreamReader(System.in));
  System.out.println("Enter string");
  String s=object.readline();
  int i;
  int n=s.length();
  String str="";
  for(i=n-1;i>=0;i--)
  str=str+s.charAt(i);
  if(str.equals(s))
  System.out.println(s+ " is palindrome");
  else
  System.out.println(s+ " is not a palindrome");
  }
  catch(Exception e){
  System.out.println("Input Error!");
  }
  }
} 

Output:

Enter string abbsd

abbsd is not palindrome

Enter string abcdedcba

abcdedcba is palindrome

Integer Palindrome or not

import java.io.*;

public class Palindrome  {
  public static void main(String [] args){
  try{
  BufferedReader object = new BufferedReader(
  new InputStreamReader(System.in));
  System.out.println("Enter number");
  int num= Integer.parseInt(object.readLine());
  int n = num;
  int rev=0;
  for (int i=0; i<=num; i++){
  int r=num%10;
  num=num/10;
  rev=rev*10+r;
  i=0;
  }
  if(n == rev){
  System.out.print("Number is palindrome!");
  }
  else{
  System.out.println("Number is not palindrome!");
  }
  }
  catch(Exception e){
  System.out.println("Out of range!");
  }
  }
} 

Output:

Enter number 1234

Number is not palindrome!

Enter number 1234321

Number is palindrome!

String reverse

class StringRever{
public static void main(String args[]){
String str="Hello World";
for(int i=str.length()-1;i>=0;i--)
  System.out.print(str.charAt(i));
}
}

Output:

dlroW olleH