Here you can find the source of toBoolean(String s)
public static Boolean toBoolean(String s)
//package com.java2s; /*//from w w w.ja v a 2s . c om * Copyright (c) 2016 XCSP3 Team (contact@xcsp.org) * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ public class Main { public static Boolean toBoolean(String s) { s = s.toLowerCase(); if (s.equals("yes") || s.equals("y") || s.equals("true") || s.equals("t") || s.equals("1")) return Boolean.TRUE; if (s.equals("no") || s.equals("n") || s.equals("false") || s.equals("f") || s.equals("0")) return Boolean.FALSE; return null; } }