Java Super Program

Pattern matching

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));

         }

      }

   }

}

Removing whitespaces

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Main

             {

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

  {

      String ExString = "This is a Java program. 

      This is another Java Program.";

      String result=removeDuplicateWhitespace(ExString);

      System.out.println(result);

   }

   public static CharSequence 

   removeDuplicateWhitespace(CharSequence inputStr) 

  {

      String patternStr = "\\s+";

      String replaceStr = " ";

      Pattern pattern = Pattern.compile(patternStr);

    Matcher matcher = pattern.matcher(inputStr);

 return matcher.replaceAll(replaceStr);

   }

}

Matching Phone Numbers

public class MatchPhoneNumber 

{

   public static void main(String args[]) 

  {

      isPhoneValid("1-999-585-4009");

      isPhoneValid("999-585-4009");

      isPhoneValid("1-585-4009");

      isPhoneValid("585-4009");

      isPhoneValid("1.999-585-4009");

      isPhoneValid("999 585-4009");

      isPhoneValid("1 585 4009");

      isPhoneValid("111-Java2s");

   }

   public static boolean isPhoneValid(String phone) 

  {

      boolean retval = false;

      String phoneNumberPattern = 

      "(\\d-)?(\\d{3}-)?\\d{3}-\\d{4}";

      retval = phone.matches(phoneNumberPattern);

      String msg = "No match: pattern:" + phone

      + "\r\n regex: " + phoneNumberPattern;

      if (retval)

      {

         msg = " Match: pattern:" + phone 

         + "\r\n regex: " + phoneNumberPattern;

      }

      System.out.println(msg + "\r\n");

      return retval;

   }

}

Counting Group of Words

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class MatcherGroupCountExample 

{

   public static void main(String args[]) 

   {

      Pattern p = Pattern.compile("J(ava)");

      String candidateString = "This is Java.

      This is a Java example.";

      Matcher matcher = p.matcher(candidateString);

      int numberOfGroups = matcher.groupCount();

      System.out.println("numberOfGroups =" + numberOfGroups);

   }

}

Searching a Word

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Main 

{

   public static void main(String args[]) 

  {

      Pattern p = Pattern.compile("j(ava)");

      String candidateString = "This is a java program. 

      This is another java program.";

      Matcher matcher = p.matcher(candidateString);

      int nextIndex = matcher.start(1);

      System.out.println(candidateString);

      System.out.println("The index for java is:" + nextIndex);

   }

}