Java - Write code to return default value If string is Blank

Requirements

Write code to return default value If string is Blank

Demo

//package com.book2s;

public class Main {
    public static void main(String[] argv) {
        String str = "book2s.com";
        System.out.println(defaultIfBlank(str));
    }//from w  ww  . j  a  va  2  s.com

    public static final String EMPTY_STRING = "";

    public static String defaultIfBlank(String str) {
        return isBlank(str) ? EMPTY_STRING : str;
    }

    public static String defaultIfBlank(String str, String defaultStr) {
        return isBlank(str) ? defaultStr : str;
    }

    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;
    }

}