Read from txt file and analyse data

Question

hi,
i am having a problem for reading data from a text file and checking whether it is a integer or not.
basically if i have a txt file with the following content:
12 45 345 500 45.67684 33
my output should be:
12 45 345 500 invalid 33
that means if there is a integer number in the file, the integer number will be printed on the screen BUT if there is anything else like a string or a double number, then "invalid" will be printed.
how can i check what kind of datatype it is??
i have the following code to start with:
try
            BufferedReader in = new BufferedReader(new FileReader(FileName));
            String l = in.readLine();
            in.close();
        catch(IOException e)
            System.out.println("IO error");
            System.exit(0);
        }

Answer 1

ok i have tried the following code:
        int index = 0;
        String[] arr = null;
        int nb = 0;
        try
            BufferedReader in = new BufferedReader(new FileReader(nameFile));
            String line = in.readLine();
            arr = line.split(" ");
            for(int i=0; i<arr.length; i++)
                index = i;
                nb = Integer.parseInt(arr);
System.out.print(nb+" ");
in.close();
catch(IOException e)
System.out.println("IO error");
System.exit(0);
catch(NumberFormatException e)
System.out.print("invalid ");
for(int j=index+1; j<arr.length; j++)
nb = Integer.parseInt(arr[j]);
System.out.print(nb+" ");
which works perfectly fine for the following scenario:
txt-file:
12 45 345 500 45.67684 33
output:
12 45 345 500 invalid 33
but what, if I have the following data in my txt file:
12 45 345 500 45.67684 33 23.234 21
then the output should be:
12 45 345 500 invalid 33 invalid 21
how can i solve this???