How can I determine the type of an input

What I mean is this :
I have to write a program that gets an integer and prints it on the screen. Otherwise, an error message should be printed.

10x in advance. :)

EDIT :
So far what I have done is this :

Code:

---

import java.util.Scanner;

public class f{
        public static boolean isItInt(String inp)
        {
                char dgts[]={'0','1','2','3','4','5','6','7','8','9'};
                int i=0,j=0,count=0;
                for (i=0; i<inp.length(); i++)
                {
                        for(j=0;j<dgts.length;j++)
                                if (inp.charAt(i)==dgts[j])
                                        count++;
                }
                if (count==inp.length())
                        return true;
                else
                        return false;
        }

        public static void main(String argv[]){
                Scanner s = new Scanner(System.in);
                String p=s.next();
                System.out.println(p);
                boolean x=isItInt(p);
                System.out.println(x);
        }
}

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But I am sure there is something easier than this, so let me know.

Integer.parseInt("1234")

hi

Quote:

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Originally Posted by QJack

But I am sure there is something easier than this, so let me know.

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in java when a number format convertion goes wrong then a exception is thrown. so try this peace of code

Code:

---

public class ExceptionExample {

        public static void main(String[] args) {
                String str = "10000";
                try {
                        System.out.println(Long.parseLong(str));
                } catch (NumberFormatException nfe) {
                        System.out.println("NumberFormatException occured ");
                        nfe.printStackTrace();
                }
        }
}

---

run the code with different str values to see what happens.

when you are accepting vis scanner use this method ...it will accept only integer.No need to have checking method for int.
nextInt()
hasNextInt()

Alright, thank u all! That was helpful.