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

/** Oct 10 
  * Input Files: 
  *        1. import java.io.*
  *        2. put "throws IOException" clause in header of method
  *        3. create a File object that is connected to an input file
  * on disk
  *        4. Create a Scanner object connected to the File object
  * created in Step 3
  *        5. Now you can read using all your "next" methods of Scanner
  * class
  *        6. When you're finished with a file, close the file
  */

public class InputFiles {
  // read ins 3 integers from a file
 public static void main(String[] args) throws IOException {
   // Step 3: create a File object
   File myFile = new File("inputData.txt");
   
   if (!myFile.exists()) {
      System.out.println("The file inputData.text is not found.");
      System.exit(0); // this will terminate the pgm
   }
   
// Step 4: create a Scanner object
   Scanner fileInput = new Scanner(myFile);
   // following I do the same thing in 1 line of code:
   //Scanner fileInput = new Scanner(new File("inputData.txt"));
   // Step 5: start reading
   int num1, num2, num3;
   num1 = fileInput.nextInt();
   num2 = fileInput.nextInt();
   num3 = fileInput.nextInt();
   
   System.out.println("I read in: " + num1 + " " + num2 + " " + num3);
   fileInput.close();
   //DO THIS AGAIN USING A LOOP
   fileInput = new Scanner(myFile);
   while (fileInput.hasNextInt()) {
     int num = fileInput.nextInt();
     System.out.println("next number: " + num);
   }
   // try to access num i will get a compiler error "cannot find symbol"
   // since num is out of scope
   // num++;
   fileInput.close();
 }
}