Printing An External File's Contents

below is my code for a homework assignment where I need to read the contents of an external file and determine the number of words within it, number of 3-letter words, and percentage of total. I've got that part down just fine, but I also have to print the external file's contents prior to displaying the above information. Below is my current code:

public class Prog512h 
{
   public static void main( String[] args)
   {
    int countsOf3 = 0; 
    int countWords = 0; 

    DecimalFormat round = new DecimalFormat("##.00"); // will round final value to two decimal places

    Scanner poem = null;
    try 
    {
        poem = new Scanner (new File("prog512h.dat.txt"));
    }
    catch (FileNotFoundException e) 
    {
        System.out.println ("File not found!"); // returns error if file is not found
        System.exit (0);
    }

    while (poem.hasNext()) 
    { 
        String s = poem.nextLine(); 
        String[] words = s.split(" "); 
        countWords += words.length; 
        for (int i = 0; i < words.length; i++) 
        { 
            countsOf3 += words[i].length() == 3 ? 1 : 0; // checks for 3-letter words
        } 
    } 

    while(poem.hasNext()) 
    {       
        System.out.println(poem.nextLine());
    }
    System.out.println();
    System.out.println("Number of words: " + countWords); 
    System.out.println("Number of 3-letter words: " + countsOf3); 
    System.out.println("Percentage of total: " + round.format((double)((double)countsOf3 / (double)countWords) * 100.0)); // converts value to double and calculates percentage by dividing from total number of words
   } 

   }

The statement

while(poem.hasNext()) 
{       
    System.out.println(poem.nextLine());
}

is supposed to print the external file's contents. However, it doesn't. When I try moving it before my prior while loop, it prints, but screws up my printed values for the # of words, 3-letter words, percentage, etc. I'm not really sure what the issue is here. Could someone provide some assistance?

Thank you in advance.

Solution

Your scanner is trying to reread the file but it is at the bottom so there are no more lines to read. You have two options:

Option 1

Create a new Scanner object for the same file (to start at the beginning again) and then call your while loop on that file (works, but not a great design).

Scanner poem2 = null;
try 
{
    poem2 = new Scanner (new File("prog512h.dat.txt"));
}
catch (FileNotFoundException e) 
{
    System.out.println ("File not found!"); // returns error if file is not found
    System.exit (0);
}

while(poem2.hasNext()) 
{       
    System.out.println(poem2.nextLine());
}

Option 2

A better option would be to display each line as you read it in. This can be accomplished by adding an extra line to the already existent while loop:

while (poem.hasNext()) 
{ 
    String s = poem.nextLine();
    System.out.println(s); // <<< Display each line as you process it
    String[] words = s.split(" "); 
    countWords += words.length; 
    for (int i = 0; i < words.length; i++) 
    { 
        countsOf3 += words[i].length() == 3 ? 1 : 0; // checks for 3-letter words
    } 
}

This only requires one Scanner object and only requires one read-through of the file which is much more efficient.