The following program uses command line arguemnts to creat a Scanner object to read from a file. Fill in the blanks to complete this java class.

public class Demo{

public static void main(String[] args) throws FileNotFoundException{

String filename;

if(args._________>0) { filename = ______;}

else { filename=________________;}

______ FileReader = openFile(filename);

}

public static String promptForFileName() {

System.out.println("Enter the file name: ");

Scanner in = new Scanner(System.in);

return in.next();

}

public static Scanner openFile(__________ filename){

File file = new File(_______);

while (!file.exists()) {

file = new File(_______________);}

return new Scanner(________);

}

}