Multiple DataInputStreams from the same FileConnection

[cyberfish]

Hi,

My program needs random access to a binary file, and since DataInputStream (or InputStream) don't support seeking backwards, I'm thinking about opening multiple InputStreams, every time I need to go backwards, and then "skip()" from there.

Does that work?

Are newly opened InputStreams positioned at the beginning of the file?

openOutputStream has an overloaded version that takes an offset, but apparently openInputStream doesn't for some reason.

Also, is skip(long) efficiently implemented in devices? Or is it read and chuck... (the emulator seems to have "real" seek)

Many thanks!

[cyberfish]

I just tried it out on the emulator and all DataInputStream's are positioned at the beginning! Great!

Now the only question that remains is -

Is "skip()" implemented efficiently on phones? (I don't think testing that in the emulator would be enough... and I don't have my phone with me at the moment)

Thanks

[arpit2agrawal]

skip(1MB) takes:
5 milliseconds on Nokia 3110 classic
10 seconds on Nokia E61i
JSR 75 is really inefficient on S60 phones

[cyberfish]

I see. Thanks.