Object Serialization

[Ole Kristian]

Hi!
I need some help here. I have a file which contains serialized objects. What I want to do is to seek backwards in this file. That is : Seek backwards from anywhere in the file and read the objects. It's easy enough to read and write objects when I go from the beginning to the end of the file, but what about the other way?
Appreciate some help here:-)

[Cindy Glass]

Do you have (or could you put) a delimiter in the file that you could tokenize on?

[pascal betz]

hi,
perhaps you can put the size of the serialiezed object in the file too ?

pascal

[Chris Camisa]

If you look in "Java 2 - Unleashed" by Jamie Jaworski
...
...
In the Input/Output Streams section it reads.
{
The Random AccessFile Class
The RandomAccessFile class provides the capability to perform I/O directly to specific locations within a file. The name random access comes from the fact that data can be read from or written to random locations within a file rather than as a continus stream of information. Random access is supported through the seek() method, which allows the pointer corresponding to the current file position to be set to arbitrary locations within the file.
RandomAccessFile implements both the DataInput and DataOutput interfaces. This provides the cability to perform I/O using primitive types.
RandomAccessFile also supports basic file read/write permissions, allowing files to be accessed in read-only or read-write modes. A mode stream argument is passed to the RandomAccessFile constructor as r or rw, indicating read-only and read-write file access. The read-only access attribute may be used to prevent a file from being inadvertently modified.
RandomAccessFile introduces several new methods besides those inherited from Object and implemented from DataInput and DataOutput. These methods include seek(), getFilePointer(), and length(). The seek() method sets the file pointer to a particular location within the file. The getFilePointer() method returns the current location of the file pointer. The length() method returns the length of the file in bytes.
}

Wouldn't that allow you to rebuild the file with primitive types?
If you rebuild it, put them in the order you need so that they can be read from the beginning to the end.
Do you think that would work? Could you just put the parts of the file together yourself in the order you need?
...since you can't read it backwards anyway...?
--==]Chris Camisa[==--

[Ole Kristian]

Well, I had hoped that I could use some sort of readObject() method on this problem..
The readObject()/writeObject() methods don't work with RandomAccessFile do they?
It's just primitive types that can be written and read to/from a file then?
I have also thought about loading the whole file in the computers memory (use an array of some sort), but I don't like the idea because these files I talking about can have a size uptil 10 MB.
Isn't that bad memory managent to use so much memory?