Java Expression and String Program

Splitting a Regular Expression

import java.util.regex.Pattern;

public class PatternSplitExample 

{

   public static void main(String args[]) 

  {

      Pattern p = Pattern.compile(" ");

      String tmp = "this is the Java example";

      String[] tokens = p.split(tmp);

      for (int i = 0; i < tokens.length; i++) 

      {

         System.out.println(tokens[i]);

      }

   }

}

Replace first occurrence of a String

import java.util.regex.Matcher;

import java.util.regex.Pattern;

            public class Main

 {

   public static void main(String args[]) 

  {

      Pattern p = Pattern.compile("hello");

      String instring = "hello hello hello.";

      System.out.println("initial String: "+ instring);

      Matcher m = p.matcher(instring);

      String tmp = m.replaceFirst("Java");

      System.out.println("String after replacing 1st Match: "+tmp);

   }

}

Check Date Format

public class Main

 {

   public static void main(String[] argv) 

  {

      boolean isDate = false;

      String date1 = "8-05-1988";

      String date2 = "08/04/1987" ;

      String datePattern = "\\d{1,2}-\\d{1,2}-\\d{4}";

      isDate = date1.matches(datePattern);

      System.out.println("Date :"+ date1+": matches with

      the this date Pattern:"+datePattern+"Ans:"+isDate);

      isDate = date2.matches(datePattern);

      System.out.println("Date :"+ date2+": matches with 

      the this date Pattern:"+datePattern+"Ans:"+isDate);

   }

}

Replace all occourances of a string

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Main 

{

   public static void main(String args[])

   {

      Pattern p = Pattern.compile("hello");

      String instring = "hello hello hello.";

      System.out.println("initial String: "+ instring);

      Matcher m = p.matcher(instring);

      String tmp = m.replaceAll("Java");

      System.out.println("String after replacing 1st Match: "+tmp);

   }

             }

Make first letter of each word in Uppercase

import java.util.regex.Matcher;

import java.util.regex.Pattern;

            public class Main 

{

   public static void main(String[] args) 

  {

      String str = "this is a java test";

      System.out.println(str);

      StringBuffer stringbf = new StringBuffer();

      Matcher m = Pattern.compile("([a-z])([a-z]*)",

      Pattern.case_insensitive).matcher(str);

      while (m.find()) 

      {

         m.appendReplacement(stringbf, 

         m.group(1).toUpperCase() + m.group(2).toLowerCase());

      }

      System.out.println(m.appendTail(stringbf).toString());

   }

}