Re: Speeding up reading from files

From:
Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 21 Jan 2010 10:14:56 -0800
Message-ID:
<AQ06n.126$Yt6.32@newsfe23.iad>
On 1/21/2010 2:31 AM, Mark wrote:

Hi,

I am using a BufferedReader to read character data in from a file. It
works but it's incredibly slow. (The file consists of a number of
separate messages, each separated by a special character. Each
message must be read into a separate string.)

I use the following code (exception handling removed for brevity):

             String text = new String("");
             BufferedReader in = null;
             in = new BufferedReader(new InputStreamReader(new
FileInputStream(_msgFile)));
             int c;
             while ((c = in.read()) != -1) {
                 if (c == '@') {
                     _msgList.add(text);
                     text = "";
                 } else {
                     text += (char)c;
                 }
             }
             if (text.length()> 0) {
                 _msgList.add(text);
             }


I would go at this a little differently. Use a BufferedInputStream with
a very large buffer and pass it to a Scanner. That way you can pull off
the Strings directly.

--

Knute Johnson
email s/nospam/knute2010/

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