/**
This program shows how to read a txt file that already exist.
To read a txt file, we use mainly two calsses:
BufferReader and FileReader:

FileReader TheFileToRead = new FileReader (NameOfFile);
BufferReader TheInputFile = new BufferReader (TheFileToRead);
Or, in one line:

BufferReader TheInputFile = new BufferReader(new FileReader (NameOfFile));

To read, we apply the method readLine() to the object TheInputFile of the 
Java predefined class BufferReader:
TheInputFile.readLine();

We use TheInputFile.close(); to close the file.


In this program, we can read  a file , test whther we have  a palindrome, 
swap, sort and gives the largest palindrome in the file Words.txt. This 
former is a simple table with a single column; otherwise, we 
might use substring Java method to locate the related string the 
long of the line.
Author: Abdurrazzak Ajaja, 2007. Version 1.0
*/


import java.io.*; //Input and Output stream packages

public class ReadFiles {


public static void main (String[] args)	throws IOException {  
//The file to read to fetch a plindrome
ReadTheFile("C:/Documents and Settings/Ajaja/My Documents/Abder/NewJava/Files/Words.txt");     
  }
  
  static  void ReadTheFile (String ThisFile)throws IOException{
  BufferedReader Entrance = new BufferedReader(new FileReader (ThisFile));
  boolean TheEndOfFile = false;
  int TheLengthOfWord;
  int StringMax = Integer.MIN_VALUE;//MIN_VALUE: predefined
  String TheLargest =  null;
  
  while(!TheEndOfFile){
  String TheLine = Entrance.readLine();
  if (TheLine != null){
  // System.out.println(TheLine); To uncomment to list the words in the list
  TheLengthOfWord = TheLine.length(); // the length of the line
  // System.out.println(TheLengthOfWord); To uncomment if we want 
  //the size (nmber of characters) of the words in the list

  if(isPalindrome(TheLine) && (TheLengthOfWord > StringMax)){
	StringMax = TheLengthOfWord;  //swap  Integer.parseInt
	TheLargest = TheLine;} 
  }
  else TheEndOfFile = true;
   
  }
  Entrance.close();
  
   if(TheLargest != null)
   System.out.println ("\n\t The largest palindrome in the list is: " + TheLargest); 
  //if we have palindromes
   else
   System.out.println("\n\t No palindrome is available in the list.");// if not
  }

    static boolean isPalindrome(String s) { // Test if a string is a word
    int Left = 0;
    int Right = s.length() - 1;
    while (Left < Right) {
      if (s.charAt(Left) != s.charAt(Right))
        return false;
      Left++;
      Right--;
    }
    return true;
  }
  
}//end of the class ReadFiles

BufferReader TheInputFile = new BufferReader(new FileReader (NameOfFile));