Re: Read a file to get an ArrayList

From:
Nigel Wade <nmw@ion.le.ac.uk>
Newsgroups:
comp.lang.java.help
Date:
Thu, 22 Jul 2010 13:24:54 +0100
Message-ID:
<i29dc3$7jf$1@south.jnrs.ja.net>
On 22/07/10 03:48, bH wrote:

On Jul 21, 10:01 pm, Joshua Cranmer <Pidgeo...@verizon.invalid> wrote:

On 07/21/2010 09:09 PM, bH wrote:

Hi All,
I want/need a coding example of getting this
data type below from a file named "t.tmp"
ArrayList<String> dimensions = new ArrayList<String>();
and a
ArrayList<String> clr = new ArrayList<String>();

These data types were written to a file before,
now I can't get the data out of the file.


How were they written into the file? If you cannot answer that, could
you describe the file as it would look in a text or hex editor? How you
read data from a file is heavily influenced by what the format of the
file is.

--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth


Hi Joshua,
Here is what was written to the
file using these named ArrayList
      ArrayList<String> dimensions = new ArrayList<String>();
      ArrayList<String> colorpxl = new ArrayList<String>();
      ......
With this :
String respName = "ColorPixlData.txt";
      System.out.println("File Saved as "+ respName);
            try {
        FileOutputStream fout = new FileOutputStream(respName);
        ObjectOutputStream out = new ObjectOutputStream(fout);

        out.writeObject(dimensions);
        out.writeObject(colorpxl);

        out.flush();
        out.close();
      }catch (IOException e) {e.printStackTrace();}

    }

Here is the start of the contents of this file.


The contents of the file won't help, as the data were written using
ObjectOutputStream it's just a stream of Java objects.

You simply read it back in the way it was written out:

 FileInputStream fis = new FileInputStream("t.tmp");
 ObjectInputStream ois = new ObjectInputStream(fis);
 ArrayList<String> dimensions = (ArrayList<String>) ois.readObject();
 ArrayList<String> colorpxl = (ArrayList<String>) ois.readObject();
 ois.close();

--
Nigel Wade

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