Find certain areas of text from a text file

Question

Hello all java Gurus! I need your help on something I am trying to do in order to learn java. I am very newbie and please show mercy if I don't understand every answer you probably give me. Here is my problem. I have text file with certain areas I need to "isolate" (to insert the data in a jTable after I solve this first).
Let's say we have the following data in a text file:
FILE IS "A.txt"
***first***
this is 1 line in first
this is  2 line in first
this is 3 line in first
***second***
this is 1 line in second
this is  2 line in second
this is 3 line in second
***third***
this is 1 line in third
this is  2 line in third
this is 3 line in third
**************I now need to read the "segment" that start with " *** blablabab *** " and ends with " ************** " and store the lines of this segment to another text file "B.txt".
So "B.txt" has let's say this "segment".
***second***
this is 1 line in second
this is  2 line in second
this is 3 line in second
**************How can I do this? I know how to read/write from/to a text file with FileReader and BufferReader but I have no idea how to experiment with this. Is there anyone who can give me a hint or a help to start?
I am very new to java so be gentle :-)
Thank you very much in advance.
Kostas

Answer 1

Well this is a very good and I think efficient way to
do but unfortunately I don't have a clue about regex
and how they work. This is something I should learn.
With the expression you wrote I would have each text
block at a time? This will be stored then to an
Arraylist like above? If you have another idea please
suggest. I am interested in learning new tricks :-)
Thanks for your reply notivago!!!
KostasRegular expressions have a somewhat steep learning curve but they are worthy the effort, they are fast and powerfull text finding tools, the whole idea is that you search the text for some pattern. I will provide you a sample code, it is half way to solve your problem, you will have to make some minor adjustements to use it you your real application(none in the RE itself I hope).
To understand it, look at the Pattern class documentation and the Matcher class documentation in the API.
* SectionExtractor.java
* version 1.0
* 25/05/2005
package samples;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
* @author notivago
public class SectionExtractor {
     * @param args
    public static void main(String[] args) {
        String text =
                 "***first***\r\n" +
                  "this is 1 line in first\r\n" +
                  "this is  2 line in first\r\n" +
                  "this is 3 line in first\r\n" +
                  "**************\r\n" +
                  "***second***\r\n" +
                  "this is 1 line in second\r\n" +
                  "this is  2 line in second\r\n" +
                  "this is 3 line in second\r\n" +
                  "**************\r\n" +
                  "***third***\r\n" +
                  "this is 1 line in third\r\n" +
                  "this is  2 line in third\r\n" +
                  "this is 3 line in third\r\n" +
        Pattern pattern = Pattern.compile( "\\*{3}(.+?)\\*{3}$(.*?)\\*{14}", Pattern.DOTALL | Pattern.MULTILINE);
        Matcher matcher = pattern.matcher(text);
        matcher.find();
        System.out.println( "Header: " + matcher.group(1) );
        System.out.println( "Text Body: \n" + matcher.group(2) );
}The sample as is, runs and give you output that should be clear on how the expression works. Try running it.
May the code be with you.