Search code examples
javabufferedreaderfilereaderfilewriterbufferedwriter

Separate a .txt file by empty line and copy into another .txt file


I've been searching the web but to no avail.

My problem is that I have one log text file that contains text like

2014-03-04 08:28:45 1WKkiT-0008Qr-M9 Message received from xx (1.2.3.41) T="q"
2014-03-04 08:28:45 1WKkiT-0008Qr-M9 Message was delivered to xxxH=xxx[11.11.11.1] C="250 Queued (0.000 seconds)"
2014-03-04 08:28:45 1WKkiT-0008Qr-M9 Completed

2014-03-04 08:28:45 1WKkiT-0008Qr-M9 DKIM: d=x=relaxed/relaxed a=rsa-sha1 t=1393921721 [verification succeeded]
2014-03-04 08:29:12 1WKkit-0005cD-UZ Message received from x x T="x"
2014-03-04 08:29:12 1WKkit-0005cD-UZ Message was delivered to xxxH=x xxx C="250 Queued (0.000 seconds)"
2014-03-04 08:29:12 1WKkit-0005cD-UZ Completed

The actual file is much larger.

What I would like is to read this whole file block by block (the blank line as a separator) and then write each block to another pre-made text file as I do so.

I am currently using a BufferedReader and BufferedWriter but am not married to the idea of using these.

Any help would be greatly appreciated, thanks


Solution

  • I think this is what you want:

    BufferedReader reader = new BufferedReader(new FileReader("text.txt"));
        String line = null;
        ArrayList<String> block = new ArrayList<String>();
        String tmp="";
        while ((line = reader.readLine()) != null) {
            if(line.equals(""))
            {
                block.add(tmp);
                tmp="";
            }
            else
            {
                tmp = tmp + line;
            }
        }
        block.add(tmp);
                reader.close();
        System.out.println(block.size());
        System.out.println(block.toString());
    

    Just run a for loop to copy that to another text file.

    Replace

    tmp = tmp + line";
    

    with

    tmp = tmp + line+"\n";
    

    if you want your string in the same format with the source file