Writing objects to a file

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Marcelo - 19 Oct 2005 18:09 GMT

Hi everybody,

I am searching the web in order to find how to write objects (Vector
objects) inside a file.

However, I don't find anything about it. Do you a class that can make
this? I just want a name in order to find the information (it's that i
don't know where to search./..)

thanks

Marcelo

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Oliver Wong - 19 Oct 2005 18:21 GMT

> Hi everybody,
>
[quoted text clipped - 6 lines]
>
> thanks

Try searching for "Serialization", "Serializable", "Serialize" and other
varations on the term.

- Oliver

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Monique Y. Mudama - 19 Oct 2005 18:25 GMT

> Hi everybody,
>
[quoted text clipped - 8 lines]
>
> Marcelo

Try searching on the word 'serialize'

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monique

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Steve Horsley - 19 Oct 2005 21:39 GMT

> Hi everybody,
>
[quoted text clipped - 8 lines]
>
> Marcelo

java.io.ObjectOutputStream
java io.ObjectInputStream

Steve

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Roedy Green - 19 Oct 2005 23:28 GMT

>I am searching the web in order to find how to write objects (Vector
>objects) inside a file.

The term you are looking for is serialization.

See http://mindprod.com/jgloss/serialization.html

for sample code generated see
http://mindprod.com/applets/fileio.html

and tell it you want to read/write serialised objects.

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http://mindprod.com Again taking new Java programming contracts.

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Marcelo - 20 Oct 2005 09:53 GMT

Hello, thanks for helping me.

I have another problem. What should I do in order to remove an Object in
my file? should i copy everything of my file into another file without
the given element and then replace the old file? Is there a another way?

thanks

Marcelo

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Thomas Weidenfeller - 20 Oct 2005 11:26 GMT

> I have another problem. What should I do in order to remove an Object in
> my file? should i copy everything of my file into another file without
> the given element and then replace the old file?

Yes.

> Is there a another way?

- Design an own, more flexible file format than just a sequence of
serialized objects, or

- Use a database.

/Thomas

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Roedy Green - 20 Oct 2005 12:08 GMT

>I have another problem. What should I do in order to remove an Object in
>my file? should i copy everything of my file into another file without
>the given element and then replace the old file? Is there a another way?

You use a database with blobs of serialised objects. The SQL engine
deals with the problem. You can't do anything other than copy with a
sequential file.

You might consider a RandomAccessFile with variable length records of
serialised groups of objects, but that gets pretty hairy pretty
quickly and is not worth the effort given how many free SQL engine
there are.

See http://mindprod.com/projects/hermitcrab.html
if you get the urge to invent a streamlined wheel.

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http://mindprod.com Again taking new Java programming contracts.

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Writing objects to a file

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