Here you can find the source of isEmpty(String input)
public static boolean isEmpty(String input)
//package com.java2s; public class Main { public static boolean isEmpty(String input) { if (input == null || "".equals(input) || "null".equals(input)) return true; for (int i = 0; i < input.length(); i++) { char c = input.charAt(i); if (c != ' ' && c != '\t' && c != '\r' && c != '\n') { return false; }/*from w w w . ja v a 2 s .c o m*/ } return true; } }