How to only get one output from a loop when testing a HashSet

I am building a program which is supposed to tell if a list of words from a text file are all unique or if there is a duplicate using a HashSet. If there is a duplicate, the only output should be "UNIQUE", and if there are no duplicates, the output should be "NOT_UNIQUE".

I believe the way to do this is to add the words from the file to the HashSet, and if a word can't be added it is because that word is a duplicate. I have already started building the program, but the program outputs "UNIQUE" for every word as opposed to just once at the end of the program. I think this has to do with my use of a while-loop and infile.readLine(), but I'm not sure what else to do here. Thank you for your help. My code is below:

import java.io.*;
import java.util.*;

public class Lab5
{
    public static void main (String[] args) throws Exception
    {
        HashSet<String> set = new HashSet<String>();
        BufferedReader infile = new BufferedReader( new FileReader( args[0] ) );
        while ( infile.ready() ) 
        {
            String word = infile.readLine();
            if ( !set.add(word) )
                System.out.println("NOT_UNIQUE \n");
            else
                System.out.println("UNIQUE \n");
        }
    } 
}