Printing to a file

Question

I am trying to print even numbers from a input.txt file to a display.txt output file. Anytime I send the output to the output console as a test it works perfect. It shows the even numbers. Anytime I use print stream and send it to a file, it only prints out the last even number.

I've researched and asked my professor who says they do not know what is wrong.

 Scanner inputfile=new Scanner(new File("input.txt"));
    double sum=0.0;
    int count=0;

    while (inputfile.hasNext())
    {
        if(inputfile.hasNextInt()) 
        {
            int next=inputfile.nextInt();
           int even=(next%2);              
           if(even==0)
           {


           PrintStream output=new PrintStream(new File("display.txt"));
          output.println(next); 
          System.out.println(next); 
           count++;

           }


        }
        else
        {
            inputfile.next();
            continue;

        }

    }

    if(count>0) 
    {

     inputfile.close();
    }
    else
    {
    System.out.println("The file doesn't contain any integers. Exit 
     Program");
    }

Expected output is all even numbers to the display.txt file. Only the last one prints in the file.

Answer 1

This is because you're instantiating PrintStream in every loop of your while loop, you want to instantiate PrintStream output = new PrintStream(new File("display.txt")); before you start your while loop.

Eg:

// More code

PrintStream output = new PrintStream(new File("display.txt"));
while (inputfile.hasNext())
{
    if (inputfile.hasNextInt())
    {
        int next = inputfile.nextInt();
        int even = (next % 2);
        if (even == 0)
        {
            output.println(next);
            System.out.println(next);
            count++;
        }
    }
    else
    {
        inputfile.next();
        continue;
    }
}

// More code