Java Examples - Pattern matching

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Problem Description:

How to print all the strings that match a given pattern from a file?

Solution:

Following example shows how to print all the strings that match a given pattern from a file with the help of Patternname.matcher() method of Util.regex class.

import java.util.regex.*;
import java.io.*;

public class ReaderIter {
   public static void main(String[] args) 
   throws IOException {
      Pattern patt = Pattern.compile("[A-Za-z][a-z]+");
      BufferedReader r = new BufferedReader
      (new FileReader("ReaderIter.java"));
      String line;
      while ((line = r.readLine()) != null) {
         Matcher m = patt.matcher(line);
         while (m.find()) {
            System.out.println(m.group(0));
            int start = m.start(0);
            int end = m.end(0);
            Use CharacterIterator.substring(offset, end);
            System.out.println(line.substring(start, end));
         }
      }
   }
}

Result:

The above code sample will produce the following result.

Ian 
Darwin
http
www
darwinsys
com
All
rights
reserved
Software
written
by
Ian
Darwin
and
others


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