Hi everybody,
This is just a general IO question. When I learned Java, I was taught that when you use a FileWriter or BufferedWriter, it's good practice to call writer.flush() after writing any line. Is this true, or is that a waste of time? I'm just curious.
Thanks,
Jezzica85
> Hi everybody,
> This is just a general IO question. When I learned
> Java, I was taught that when you use a FileWriter or
> BufferedWriter, it's good practice to call
> writer.flush() after writing any line. Is this true,
> or is that a waste of time? I'm just curious.
>
> Thanks,
> Jezzica85
Flush will commit the data you have written to your disk. Sort of like close() but leaves the stream open.
Thank you deAppel,
I did know that about writer.flush(), what I meant by the question is, would it be more efficient to call writer.flush() less, and somehow monitor the size of the buffer, or doesn't it matter how many times you call writer.flush()?
Jezzica85
If you are concerned about losing output when your Java program crashes,
you can flush the output buffers. The reason flushing is not automatic
is that it is more efficient to minimize the number of calls to the underlying
file system's write operation -- buffered steams wait and flush themselves
when the buffer is full. Also see PrintWriter's auto flush property.
Thanks, I didn't know that about buffered streams. I guess I won't worry about flushing them then.
Jezzica85
> Thanks, I didn't know that about buffered streams. I
> guess I won't worry about flushing them then.
What one does have to remember is to close them, because close calls flush. A common error people see is when they run a short program that writes a small amount of text to a file. After the program runs they find the file is empty -- they forgot to close.
