Searching Duplicate Words

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Main

   public static void main(String args[]) throws Exception

      String duplicatePattern = "\\b(\\w+) \\1\\b";

      Pattern p = Pattern.compile(duplicatePattern);

      int matches = 0;

      String phrase = " this is a test ";

      Matcher m = p.matcher(phrase);

      String val = null;

      while (m.find()) {

         val = ":" + m.group() + ":";

         matches++;

      if(val>0)

         System.out.println("The string

         has matched with the pattern.");

      else

      System.out.println("The string

      has not matched with the pattern.");

Finding Word Occurrence

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Main

   public static void main(String args[]) throws Exception

      String candidate = "this is a test, A test.";

      String regex = "\\ba\\w*\\b";

      Pattern p = Pattern.compile(regex);

      Matcher m = p.matcher(candidate);

      String val = null;

      System.out.println("Input: " + candidate);

      System.out.println("Regex: " + regex + "\r\n");

      while (m.find())

         val = m.group();

         System.out.println("Match: " + val);

      if (val == null)

         System.out.println("No matches: ");

}