java - Why is hasNextInt() returning false here? -

this first time scanning file in java. i'm trying read list of integers 1 text file, operate on them, , read them file. initial file looks this:

1234 9876 2345 

i'm using while loop , reading hasnextint (after running program , checking initial text file, i'm sure values there), i'm getting 0 output new text file, assume hasnextint() returning false. sure, skipped scan , operated directly on each arraylist element using loop, , output written new file perfectly. here's code:

    try {         file infile = new file("input.txt");         file outfile = new file("output.txt");          filewriter inwriter = new filewriter(infile);         filewriter outwriter = new filewriter(outfile);         scanner inreader = new scanner(infile);          numberarray.add(1234); //adding numbers array initialized         numberarray.add(9876);         numberarray.add(2345);          system.out.println("the raw numbers are:");          (int n : numberarray) {             inwriter.write(n + "\r\n");             system.out.println(n);         }          system.out.println("\nthe new numbers are:");          while (inreader.hasnextint()) {             int newnumber = inreader.nextint();             int checkdigit = (newnumber / 7);             int finalnumber = (newnumber % checkdigit);             outwriter.write("" + newnumber + finalnumber + "\r\n");             system.out.println("" + newnumber + finalnumber);         }          inwriter.close();         outwriter.close();         inreader.close();      } catch (filenotfoundexception fnfe) {         system.out.println("there problem infile file");     } catch (ioexception ioe) {         system.out.println("there problem opening outfile file");     } 

you have close inwriter prior reading in numbers file.

inwriter won't output text file until closed, reader isn't seeing because technically nothing there yet.