Java - Write code to check if a string is Blank

Requirements

Write code to check if a string is Blank

Demo

//package com.book2s;

public class Main {
    public static void main(String[] argv) {
        String str = "book2s.com";
        System.out.println(isBlank(str));
    }//from   w w w. ja  va2 s  .  c o m

    public static boolean isBlank(String str) {
        int length;

        if ((str == null) || ((length = str.length()) == 0)) {
            return true;
        }

        for (int i = 0; i < length; i++) {
            if (!Character.isWhitespace(str.charAt(i))) {
                return false;
            }
        }

        return true;
    }

}