Re: Reading data into an Array

From:

"Jeff Higgins" <oohiggins@yahoo.com>

Newsgroups:

comp.lang.java.help

Date:

Mon, 2 Jul 2007 18:52:20 -0400

Message-ID:

<2mfii.63$4J.8@newsfe12.lga>

<christopher_board@yahoo.co.uk> wrote in message
news:1183412146.507512.51230@n2g2000hse.googlegroups.com...

On 2 Jul, 17:01, Roedy Green <see_webs...@mindprod.com.invalid> wrote:

On Mon, 02 Jul 2007 05:40:43 -0700, christopher_bo...@yahoo.co.uk
wrote, quoted or indirectly quoted someone who said :

i am trying to read data from a text file and add it into an Array so
that I can read the data from the Array back in again. I haven't got a
clue how to create an Array.

seehttp://mindprod.com/jgloss/gotchas.html#ARRAY
seehttp://mindprod.com/jgloss/array.htmlhttp://mindprod.com/jgloss/arraylist.html

Usually you want an ArrayList since you don't know how many elements
there will be to start.
--
Roedy Green Canadian Mind Products
The Java Glossaryhttp://mindprod.com

The program has a text file stored somewhere on the computer which the
program will read. The file will have a long list of numbers inside
the file which may look something like this 49175630573014302316. The
file is read in once at the launch of the program. To save process
power of the computer I only want the file to be read in once. I
thought an Array would be best to do this but I am not sure as I am a
novice to java. I won't know how big the file is, it could be smaller
or larger. There will be a list box that will only display part of the
data for examble if the file reads something like 4917563057301430.
Then the list box will only display every other 2 numbers for example
in this example it would only show 17,30,30,30.

Sorry if this is not clear it is quite hard to explain what the
program is going to do the file.

Any help in what would be the best way in order to do this would
highly appreciated.

Thanks for any help that you can give me in this matter.

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;

public class Test
{
  static char[] array;

  public static void main(String[] args)
  {
    writeData();
    readData();
  }

  static void writeData()
  {
    File f = new File("bytes");
    String fileContents =
      "49175630573014302316";
    try
    {
      FileWriter fos = new FileWriter(f);
      fos.write(fileContents);
      fos.close();
    }
    catch (FileNotFoundException e)
    {
      e.printStackTrace();
    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }

  static void readData()
  {
    try
    {
      File f = new File("bytes");
      FileInputStream fis = new FileInputStream(f);
      int i;
      StringBuffer buf = new StringBuffer();
      while ((i = fis.read()) > -1)
      {
        buf.append((char) i);
      }
      fis.close();
      array = buf.toString().toCharArray();
      for (char c : array)
      {
        System.out.print(c);
      }
    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }
}