Java tutorial
/** * This file is part of pwt. * * pwt is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser * General Public License as published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * pwt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License along with pwt. If not, * see <http://www.gnu.org/licenses/>. */ package fr.putnami.pwt.core.widget.client.helper; import com.google.gwt.i18n.client.NumberFormat; import com.google.gwt.text.shared.Parser; import java.math.BigInteger; import java.text.ParseException; public final class BigIntegerParser implements Parser<BigInteger> { private static BigIntegerParser instance; private BigIntegerParser() { } @Override public BigInteger parse(CharSequence object) throws ParseException { if ("".equals(object.toString())) { return null; } try { return BigInteger.valueOf((long) NumberFormat.getDecimalFormat().parse(object.toString())); } catch (NumberFormatException e) { throw new ParseException(e.getMessage(), 0); } } public static BigIntegerParser get() { if (BigIntegerParser.instance == null) { BigIntegerParser.instance = new BigIntegerParser(); } return BigIntegerParser.instance; } }