Checks if the String contains only whitespace in Java

//w w w. jav a2s. c  o m
public class Main {
  public static boolean isWhitespace(String str) {
      if (str == null) {
          return false;
      }
      int sz = str.length();
      for (int i = 0; i < sz; i++) {
          if ((Character.isWhitespace(str.charAt(i)) == false)) {
              return false;
          }
      }
      return true;
  }
  public static void main(String[] argv){
    System.out.println(isWhitespace("java2s.com") );
  }
}