/*license*\ XBN-Java: Copyright (C) 2014, Jeff Epstein (aliteralmind __DASH__ github __AT__ yahoo __DOT__ com) This software is dual-licensed under the: - Lesser General Public License (LGPL) version 3.0 or, at your option, any later version; - Apache Software License (ASL) version 2.0. Either license may be applied at your discretion. More information may be found at - http://en.wikipedia.org/wiki/Multi-licensing. The text of both licenses is available in the root directory of this project, under the names "LICENSE_lgpl-3.0.txt" and "LICENSE_asl-2.0.txt". The latest copies may be downloaded at: - LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt - ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt \*license*/ package com.github.xbn.examples.lang.non_xbn; import java.util.Scanner; import org.apache.commons.lang3.math.NumberUtils; /** <p>Confirm a user-input number is a valid number by reading a string an testing it is numeric before converting it to an it--this loops until a valid number is provided.</p> <p>{@code java com.github.xbn.examples.lang.non_xbn.VerifyUserInputIsANumberWithIsNumber}</p> * @since 0.1.0 * @author Copyright (C) 2014, Jeff Epstein ({@code aliteralmind __DASH__ github __AT__ yahoo __DOT__ com}), dual-licensed under the LGPL (version 3.0 or later) or the ASL (version 2.0). See source code for details. <a href="http://xbnjava.aliteralmind.com">{@code http://xbnjava.aliteralmind.com}</a>, <a href="https://github.com/aliteralmind/xbnjava">{@code https://github.com/aliteralmind/xbnjava}</a> **/ public class VerifyUserInputIsANumberWithIsNumber { public static final void main(String[] ignored) { int num = -1; boolean isNum = false; do { System.out.print("Number please: "); String strInput = (new Scanner(System.in)).next(); if(!NumberUtils.isNumber(strInput)) { System.out.println(strInput + " is not a number. Try again."); } else { //Safe to convert num = Integer.parseInt(strInput); isNum = true; } } while(!isNum); System.out.println("Number: " + num); } }