/*
 * T03n04.java -- Using BufferedReader to read lines of a text file.
 * This is how you had to do it before the release of Java 1.5.
 * Be sure to run T03n02.java before attempting to run this program.
 *
 * It's hard not to notice the clutter caused by the three sets of
 * try/catch blocks.  We could put all three sections of code in one
 * try/catch pair, but that doesn't allow us to tailor the error message.
 * We could compress this a bit by putting the common catch code into a
 * static method.
 *
 * We use a priming read on the input loop, because it's possible that
 * the input file is empty.  If so, the first read will get nothing,
 * and we don't want to print a null String.
 * 
 * Why do we need BufferedReader in addition to FileReader?
 * It is entirely possible to read the file w/o a BufferedReader object, but
 * buffering the input stream is usually more efficient.  (Why?  Take a
 * class on OS design to find out!)
 */

import java.io.*;

public class T03n04
{
    public static void main (String [] args) 
    {
        final String     fileName = "T03n02.out";
        File             fileRef;
        FileReader       fileStream;
        BufferedReader   textStream = null;
        String           aLine = null;

        System.out.println("Reading some text from the file '"
                       + fileName + "'...");

        try {

            fileRef = new File(fileName);
            fileStream = new FileReader(fileRef);   // Throws the exception
            textStream = new BufferedReader(fileStream);

        } catch (FileNotFoundException e) {

            System.out.println("I/O ERROR:  Your requested file does not"
                             + "seem to exist.\nHere's what "
                             + "I can tell you:");
            System.out.println("  The Error: " + e.getClass().getName());
            String mesg = e.getMessage();
            if (mesg == null) {
                System.out.println("The message:  None.");
            } else {
                System.out.println("The message: " + mesg);
            }
            System.out.println("The stack trace:");
            e.printStackTrace();

        } 

        System.out.println("-----------------------------------------");

        try {

            aLine = textStream.readLine();
            while (aLine != null) {
                System.out.println(aLine);
                aLine = textStream.readLine();
            }

        } catch (IOException e) {

            System.out.println("I/O ERROR:  Something went wrong with the "
                             + "reading of the text file.\nHere's what "
                             + "I can tell you:");
            System.out.println("  The Error: " + e.getClass().getName());
            String mesg = e.getMessage();
            if (mesg == null) {
                System.out.println("The message:  None.");
            } else {
                System.out.println("The message: " + mesg);
            }
            System.out.println("The stack trace:");
            e.printStackTrace();

        } 

        System.out.println("-----------------------------------------");

        try {

            textStream.close();

        } catch (IOException e) {

            System.out.println("I/O ERROR:  Something went wrong with the "
                             + "closing of the text stream.\nHere's what "
                             + "I can tell you:");
            System.out.println("  The Error: " + e.getClass().getName());
            String mesg = e.getMessage();
            if (mesg == null) {
                System.out.println("The message:  None.");
            } else {
                System.out.println("The message: " + mesg);
            }
            System.out.println("The stack trace:");
            e.printStackTrace();

        } 

        System.out.println("Done!");

    }
}