import java.io.PrintWriter;
import java.io.FileWriter;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.util.Scanner;


/*
  Author:  James Tam
  Version: March 31, 2015

  * Reads 4 lines of text from the user
  * Writes the lines, one-at-a-time to a file
  * Opens and reads the lines from file until the last line
  echoing the contents of each line onscreen.

*/

public class Driver
{
    final static int MAX = 4;
    public static void main(String [] args)
    {
        String line = null;
        String [] paragraph = null;
        int i;
        Scanner in;
 
        PrintWriter pw = null;
        FileWriter fw = null;
        BufferedReader br = null;
        FileReader fr = null;

        in = new Scanner(System.in);
        paragraph = new String[MAX];

        // Get paragraph information from the user.
        for (i = 0; i < MAX; i++)
        {
            System.out.print("Enter line of text: ");
            line = in.nextLine();
            paragraph[i] = line;  
        }

        // Write paragraph to file
        try
	{
            fw = new FileWriter("data.txt");
            pw = new PrintWriter(fw);
            for (i = 0; i < MAX; i++)
	    {
                pw.println(paragraph[i]);
            }
            fw.close();
        }
        catch (IOException e)
	{
	    System.out.println("Error writing to file");
	}

        // Read information from file
        try
	{
	    fr = new FileReader("data.txt");
            br = new BufferedReader(fr);
            line = br.readLine();

            if (line == null)
                System.out.println("Empty file, nothing to read");

            // Although the program just wrote 4 lines of text it's not a good idea
            // to rely on a fixed file size. Consequently programs should check for
            // end of file. 
            // readLine() returns a null string when end of file reached.
            while (line != null)
            {
                System.out.println(line);
                line = br.readLine();
            }
            fr.close();
	}
        catch (FileNotFoundException e)
	{
            System.out.println("Could not open data.txt");
	}
        catch (IOException e)
	{
            System.out.println("Trouble reading from data.txt");
	}
    }
}