Re: FileReader / BufferedReader Help
DJ wrote:
Please don't top-post, it makes reading the thread very difficult.
"Knute Johnson" <nospam@rabbitbrush.frazmtn.com> wrote in message
news:pCQti.38753$dA7.32233@newsfe16.lga...
DJ wrote:
Perhaps my use of "terminator" is incorrect.
I have two simple text files such that file1.txt consists of a single
line of text (no crlf), and file2.txt consists of the identical line of
text followed by a second blank line (implying the line is terminated
with crlf, no?). After retrieving each line using readLine and assigning
the lines to strings, the equals method indicates the two strings are
equal.
I would have thought they'd be different given that the line read from
file2.txt is terminated with crlf.
"Roedy Green" <see_website@mindprod.com.invalid> wrote in message
news:bgafb3pcppk35t1oa1j4l3a1t3mfsmndpb@4ax.com...
On Mon, 6 Aug 2007 18:40:42 -0400, "DJ" <ddjames@tampabay.rr.com>
wrote, quoted or indirectly quoted someone who said :
For instance, a line of text terminated with crlf (newline) was
determined equal to the same line of text without the crlf termination.
that makes no sense. You don't have a line unless there is a
terminator. BufferedReader treats \r\n and \n both as line
terminators in Windows.
If you were interested in the details of the line terminator, use read
rather than readLine so that it gets passed through to the app.
See http://mindprod.com/applet/fileio.html
--
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com
Do you know where to find the docs?
http://java.sun.com/javase/6/docs/specific
See BufferedReader
"readLine
public String readLine()
throws IOException
Reads a line of text. A line is considered to be terminated by any one
of a line feed ('\n'), a carriage return ('\r'), or a carriage return
followed immediately by a linefeed.
Returns:
A String containing the contents of the line, not including any
line-termination characters, or null if the end of the stream has been
reached
Throws:
IOException - If an I/O error occurs"
--
Knute Johnson
email s/nospam/knute/
Knute,
Okay - I'll take my lumps now. I missed the whole "not including any
line-termination characters..." bit. Guess I was glossing over the material
too quickly..
Moving forward, since the line terminators are important, I can see I'll
have to use read instead of readLine as Roedy suggested. That said, I'm not
clear on how to implement read to get an entire lines' worth of text from
each file so that I can compare the files "line" for "line". Read returns an
integer value for each character, but how do I determine when I've read the
entire line? Test for a crlf (10/13) pair? I'm also not sure how to convert
read's int values to characters so I can write the lines that don't match to
my results file.
Any clues? I'm not looking to have the code written for me. Rather, just
point me in the right direction(s).
BTW, I know where the docs live. And I really am trying to get more out of
this exercise than honing my copy&paste skills. ;)
Thanks,
~ Dave
The problem isn't the line-termination.
You have two files with a differing number of lines (file2 actually has two
lines, the second is empty apart from its line terminator). Your while loop
terminates the comparison when it reaches the end of either file, so it stops
comparing the files when the end of the shorter file is reached. In this
instance that is after the comparison of the first line of each file. The
second attempted read fails for file1, so the loop terminates and the second
line of file2 is never read.
--
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555