Help with serialization

[Christo]

as part of a project at uni i have been asked to provide object persistance
through files

I have opted for serialization

my question is quite simple

when u use serialization is an object saved to a single file or are more
than one object(s) saved to a single file?

say i have three objects, will they all be saved into one file or will there
be three seperate files each having one object saved into them?

also say i have a superclass implmenting the java.io.Seriali zable

will all subclasses of that superclass automatically implement the
java.io.Seriali zable or will i need to make those subclasses implement the
Serializable seperately?

any help would be appreciated

PS -
public class UserData implements java.io.Seriali zablei understand that
but..public class UserData extends User...how would i implement the
java.io.Seriali zable in that class? would it be...public class UserData
implements java.io.Seriali zable extends UserORpublic class UserData extends
User implements java.io.Seriali zableThanks in advanceChristo

[Eric A. Maginniss]

Re: Help with serialization

Christo wrote:[color=blue]
> as part of a project at uni i have been asked to provide object persistance
> through files
>
> I have opted for serialization
>
> my question is quite simple
>
> when u use serialization is an object saved to a single file or are more
> than one object(s) saved to a single file?
>
> say i have three objects, will they all be saved into one file or will there
> be three seperate files each having one object saved into them?
>
> also say i have a superclass implmenting the java.io.Seriali zable
>
> will all subclasses of that superclass automatically implement the
> java.io.Seriali zable or will i need to make those subclasses implement the
> Serializable seperately?
>
> any help would be appreciated
>
> PS -
> public class UserData implements java.io.Seriali zablei understand that
> but..public class UserData extends User...how would i implement the
> java.io.Seriali zable in that class? would it be...public class UserData
> implements java.io.Seriali zable extends UserORpublic class UserData extends
> User implements java.io.Seriali zableThanks in advanceChristo
>
>[/color]

Serialization is about converting objects into Streams of
reconstitutable data. What you do with the stream is up to you. Also,
once a class implements an interface all subclasses automatically
implement it.

Java API Javadocs are your friend:
http://java.sun.com/j2se/1.4.2/docs/...putStream.html

Another thing to look up is the java keyword "transient"