import java.io.File;
import java.util.Scanner;
import java.io.FileNotFoundException;

/**
 * LineReader.java
 * Jeff Ondich, Carleton College, 2014-01-01
 * Modified: Anna Rafferty, Carleton College, 2016-08-24
 * Modified: Jed Yang, Carleton College, 2017-01-07
 *
 * A very brief introduction to File and Scanner, excessively commented
 * for tutorial purposes.
 *
 * This is the Java half of a pair of parallel examples in Python and Java.
 * See linereader.py.
 *
 * Try a few things:
 *
 * 1. Create a small text file called somelines.txt, put it in the same
 *    directory as LineReader.java, and then compile and run LineReader.
 *    ("javac LineReader.java" followed by "java LineReader")
 *
 * 2. What happens when you change the inputFilePath variable to
 *    "nonexistent.txt"?
 *
 * 3. What happens when you remove the "= null" from the Scanner declaration?
 *
 * 4. What happens when you remove the try/catch blocks and just do
 *    "Scanner scanner = new Scanner(inputFile)"?
 *
 * 5. Visit the java String documentation and play around with some String
 *    methods other than toUpperCase.  (Since this is open-ended, you should do
 *    this *AFTER* you've tried out all the other sample programs.)
 */
public class LineReader
{
   public static void main(String[] args)
   {
      // Create a File object connected to the file you want to read.
      String inputFilePath = "somelines.txt";
      File inputFile = new File(inputFilePath);

      // Create a Scanner object connected to your file.  This is where the JVM
      // tries to actually open the file, and thus this is where an exception
      // can occur.  That's why there's a try/catch block to catch the
      // exception.  It allows the programmer to build in a way for the program
      // to recover from the error (in this case, by just printing the error
      // for the user).
      Scanner scanner = null;
      try
      {
         scanner = new Scanner(inputFile);
      }
      catch (FileNotFoundException e)
      {
         System.err.println(e);
         System.exit(1);
      }

      // Get one line at a time from the file, and print each line in upper
      // case to standard output.
      int numberOfLines = 0;
      while (scanner.hasNextLine())
      {
         String line = scanner.nextLine();
         System.out.println(line.toUpperCase());
         numberOfLines++;
      }
      scanner.close();
      System.out.println("\nNumber of lines: " + numberOfLines);
   }
}