Object orientatted programming and classes

[hargi]

Really strugling to get my head round OOP.

Im trying to learn Java as well.
Im wanting to do a what i think is a small app. to create usernames from a csv file

If I have 2 files, one a csv file containing firstname , surname and the other is just a wordlist.txt file.

And my output is to a new csv file with firstinitial.surname, firstname,surname,password (from a word list)

I have this so far.

public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
      try
      {
         Readfile read = new Readfile();
         read.run();
      }
      // Report any IOExceptions which occur
      catch (IOException IOEx)
      {
         System.out.println("Problems reading file " + IOEx);
      }
   }
}

and then

import java.io.*;
import java.util.*;
/**
 **
 * 
 */

public class Readfile {

     private FileReader fr;
     private BufferedReader br;
     private PrintWriter pw;

     public void run() throws IOException
    {
        String nextLine;
        Scanner sc = new Scanner(new File("export.csv"));
        while (sc.hasNext())
        {
            nextLine = sc.nextLine();
            System.out.println(nextLine);
        }

        sc.close();
    }

So i can read in from one file and output to the output bar, i take it i will need to make new line an array so i can split the line up with stringtokenizer??

Im old school so not got my head around none linear programming as such.

what kinda classes or methods should i have,

IF you can help thank you so much in advance

 

[hargi]

Thanks drak3.

I have a good book that explains it in cat and dog speak that i understand but the putting it into practice is another thing.

ok I got this so far

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package gmailcsvapp;



/**
 *
 * @author 
 */

import java.io.*;
import java.io.FileNotFoundException;
public class Main {

    /**
     * @param args the command line arguments
     */
    
    public static void main(String args[]) throws FileNotFoundException, EmptyFileException
    {
        String importfile = "export.csv";

      try
        {
            Readfile reader1 = new Readfile(importfile);
            while (reader1.iter.hasNext())
           
            {
               System.out.println(reader1.getNextLine()+reader1.password());
            }
        }
        catch (EmptyFileException message){
            System.out.println(importfile + " threw a Empty File Exception; the details were as follows - " + message);
        }
       catch (FileNotFoundException message){
            System.out.println(importfile + "Throw a File Not Found Error");
       }
    }
}

and then this

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package gmailcsvapp;



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

public class Readfile
{
   public File file;
   

   public ArrayList<String> userCollection = new ArrayList<String>();
   public Iterator <String>iter;
   public static final String NONE_LEFT = "";

   

   public Readfile(String filename) throws FileNotFoundException, EmptyFileException
    {
        file = new File(filename);
        Scanner sc = new Scanner(file);

        if(sc.hasNext())
        {
           while(sc.hasNext())
           {
               //assuming that each line only has one word (would add additional logic to split lines here if necessary)
               userCollection.add(sc.nextLine().toLowerCase());
           }

        }
        else
        {
           throw new EmptyFileException(filename +  " contains no words");
        }
        iter = userCollection.iterator();
    }




    public String getNextLine()
    {
        if(iter.hasNext())
        {
            return iter.next();
        }
        else
        {
            return NONE_LEFT;
        }
    }


    public ArrayList<String> passwordCollection = new ArrayList<String>();
    public Iterator <String>iterpass;
    public File file1;

       public String password() throws FileNotFoundException, EmptyFileException
   {
       file1 = new File("passwordlist.txt");
       Scanner Pass = new Scanner(file1);

        if(Pass.hasNext())
        {
           while(Pass.hasNext())
           {
               //assuming that each line only has one word (would add additional logic to split lines here if necessary)
               passwordCollection.add(Pass.nextLine().toLowerCase());
           }

        }
        else
        {
           throw new EmptyFileException("passwordlist.txt contains no words");
        }
        iterpass = passwordCollection.iterator();
        long number = (Math.round(Math.random() * 100));
        Random generator = new Random();
        int index = generator.nextInt ( passwordCollection.size() );
        if( index >-1 ) return ( ","+passwordCollection.get(index)+number);



       return (","+iterpass.next()+number);
   }

}

Ignorring the password bit which works, this now prints out, firstname,surname,and a randompassword.

anypointers on getting the fitstinitial.surname at the begining

 

[hargi]

Thank you so much for that, I slowly understanding it,

Got it to do everything it needs to do

How difficult would it be to now use some kind of file selector to select a file to open and a file name to export it to rather than it been hard coded