Re: Easy way to read the contants of a folder/directory and output contents to file?

From:
Eric Sosman <esosman@ieee-dot-org.invalid>
Newsgroups:
comp.lang.java.help
Date:
Mon, 12 Dec 2011 10:03:36 -0500
Message-ID:
<jc5549$sj3$1@dont-email.me>
On 12/12/2011 9:42 AM, Thee Chicago Wolf [MVP] wrote:

Iterating through the array wasn't too hard with listFiles (thanks for
that BTW) but I wound up using the following to accomplish what I
needed to get output to the file to work. It was just a simple matter
of the for loop

FileWriter folderOutput = new FileWriter("filelist.txt");
PrintWriter outFile = new PrintWriter(folderOutput);
for(int i = 0; i< list.length; i++)
{
outFile.write(String.valueOf(list[i]+"\n"));
}
folderOutput.close();


     This looks like it might work, but it also might not. I'd
suggest using outFile.close() instead of folderOutput.close() to
avoid the possibility that the PrintWriter might be holding on
to a few characters that have not yet been flushed. It might be
best to get rid of the `folderOutput' name altogether, just to
make this particular mistake harder to make.

     There are also a few simplifications available. First, there's
an easier way to iterate through an array (rather oddly named `list').
Second, there's no need to use String.valueOf() on a String argument.
Finally, you could use PrintWriter's own methods to deal with line
termination instead of worrying about it yourself.

     Putting it all together yields

    PrintWriter outFile = new PrintWriter(
        new FileWriter("filelist.txt"));
    for (File f : list) {
        outFile.println(f);
    }
    outFile.close();

     "Production grade" code would probably use outFile.checkError()
to detect any I/O errors that the PrintWriter may have encountered.

--
Eric Sosman
esosman@ieee-dot-org.invalid

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