Finding duplication of words : Validation « Regular Expressions « Java Tutorial

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

public class MainClass {
  public static void main(String args[]) {

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

    Pattern p = null;
    try {
      p = Pattern.compile(duplicatePattern);
    } catch (PatternSyntaxException pex) {
    // count the number of matches.
    int matches = 0;

    // get the matcher
    Matcher m = p.matcher(phrase);
    String val = null;

    // find all matching Strings
    while (m.find()) {
      val = ":" + + ":";

8.10.1.Primitive address validation
8.10.2.Date format consists of one or two digits followed by a hyphen, followed by one or two digits, followed by a hypen, followed by four digits
8.10.3.Finding duplication of words
8.10.4.Name validation
8.10.5.Phone number validation
8.10.6.Zip code validation
8.10.7.String manipulation using English synonyms
8.10.8.Match a digit