Returns a new string with all the whitespace removed in Java

/*  w w w.j  av a  2 s  .c o m*/
public class Main{
  /**
   * Returns a new string with all the whitespace removed
   * 
   * @param s the source string
   * @return the string without whitespace or null
   */
  public static String removeWhiteSpace(String s)
  {
     String retn = null;
     
     if (s != null)
     {
        int len = s.length();
        StringBuffer sbuf = new StringBuffer(len);
        
        for (int i = 0; i < len; i++)
        {
           char c = s.charAt(i);
           
           if (!Character.isWhitespace(c))
               sbuf.append(c);
        }
        retn = sbuf.toString();
     }
     return retn;
  }
  public static void main(String[] argv){
    System.out.println(removeWhiteSpace("from java2s.c o m"));
  }
}