Re: Size of an arraylist in bytes

From:
Lew <lewbloch@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 20 Nov 2011 20:28:16 -0800 (PST)
Message-ID:
<23614233.2468.1321849696743.JavaMail.geo-discussion-forums@prfx4>
On Sunday, November 20, 2011 1:11:00 PM UTC-8, sara wrote:

Here is the code:
 
        ArrayList<Integer> tmp=new ArrayList<Integer>();

*DO NOT USE TAB CHARACTERS TO INDENT USENET CODE LISTINGS!*

         tmp.add(-1);
        tmp.add(-1);
        System.out.println(DiGraph.GetBytes(tmp).length);
        tmp.set(0, 10);
        System.out.println(DiGraph.GetBytes(tmp).length);
 
 
    public static byte[] GetBytes(Object v) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos;
        try {
            oos = new ObjectOutputStream(bos);
            oos.writeObject(v);
            oos.flush();
            oos.close();
            bos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        byte[] data = bos.toByteArray();
        return data;
    }
 
The problem is I need to write multiple arraylists on disk and later


The problem is that the code you posted won't compile.

on I update the elements of them. I store the starting location of
arraylists and their size such that later I can refer to them. If the
size of objects change then it messes up! Could you please help?


Java changes the sizes of things in surprising ways, and makes no promises =
about the size of an 'ArrayList' in the way you're asking.

What do you really want to do?

On Nov 20, 1:05 pm, markspace <-@.> wrote:


*DO NOT TOP-POST!*

--
Lew

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