why is int required as FileOutputStream's argument?

[Sriram Sharma]

Dear All,

I was trying some very basic stuffs using input and output streams.
Here below is the snippet...

            fis = new FileInputStream("F:\\fileToRead.txt");
            fos = new FileOutputStream("writtenFile.txt");
            int c;
            while((c = fis.read())!=-1)
            {
                fos.write(c);
            }

The above stated code snippet works fine if executed as such. But......
If I give "fos.write(fis.read())" instead of "fos.write(c)", the output file contains only some junk characters.
Can somebody explain me why this is so???

Regards,
Ram

[Paul Clapham]

Well, for one thing you would only be writing every other byte from the input to the output, instead of every byte.

[Sriram Sharma]

Hi Paul/other ranchers,

Thanks for replying...
But still, I did not get what you wanted to communicate.
Could you please elaborate it for me?

Regards,
Ram

[Rob Spoor]

InputStream.read() reads one character, moves forward and then returns the read character. So if you call read() twice in the loop, once in the guard and once in the writing, then the first, third, fifth etc bytes are not written. Also, if there is an odd number of bytes then the guard will return something other than -1, but the read used in the write returns -1 and this is then written as a byte.

You could try without reading in the guard but you wouldn't know when to stop:

boolean done = false;
while (!done)
{
    fos.write(fos.read());
    // but how will done be set to true?
}

[Sriram Sharma]

Thanks a lot Rob. That was pretty good explanation
-Ram