determine the encrypted file size

[Peter]

Hi
I use the following code to encrypt a file. How can i determine the size
of the file after encrypt? Because i want to set up a progress bar.

FileInputStream in = new FileInputStream(new
File("file.txt"));
FileOutputStream fileOut = new
FileOutputStream("newfile.txt");

CipherOutputStream out = new CipherOutputStream(fileOut,
encryptCipher);

byte[] buffer = new byte[1024];
int length;
while ( (length = in.read(buffer)) != -1) {
out.write(buffer, 0, length);
}


thanks
from Peter ([email protected])

 

[Roedy Green]

I use the following code to encrypt a file. How can i determine the size
of the file after encrypt? Because i want to set up a progress bar.

You can't, but you can do some samples and get an estimate of the
bloat factor.

You can also do your progress based on how much you have encrypted,
not the final size.

 

[ak]

I use the following code to encrypt a file. How can i determine the
size

of the file after encrypt? Because i want to set up a progress bar.

use input, not output to determine progress

 

[Liz]

Too late, you are writing it as you create it, by the time
you know the length of the file it is already written, so
progress = "done";

 

[Peter]

use input, not output to determine progress

Perfectly solve my problem
thanks.
from Peter