001/**
002 * The MIT License (MIT)
003 *
004 * Copyright (c) 2015-2016 decimal4j (tools4j), Marco Terzer
005 *
006 * Permission is hereby granted, free of charge, to any person obtaining a copy
007 * of this software and associated documentation files (the "Software"), to deal
008 * in the Software without restriction, including without limitation the rights
009 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
010 * copies of the Software, and to permit persons to whom the Software is
011 * furnished to do so, subject to the following conditions:
012 *
013 * The above copyright notice and this permission notice shall be included in all
014 * copies or substantial portions of the Software.
015 *
016 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
017 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
018 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
019 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
020 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
021 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
022 * SOFTWARE.
023 */
024package org.decimal4j.arithmetic;
025
026import java.math.BigInteger;
027
028/**
029 * Provides ports of methods that are available in JDK 1.8 to make code run in 
030 * earlier JDK's.
031 */
032public final class JDKSupport {
033
034    /**
035         * Copied from {@code BigInteger.longValueExact()} added in Java 1.8.
036         * <p>
037         * Converts the {@code BigInteger} argument to a {@code long}, checking for lost
038         * information. If the value of this {@code BigInteger} is out of the range
039         * of the {@code long} type, then an {@code ArithmeticException} is thrown.
040         * 
041         * @param value the {@code BigInteger} value to convert to a long
042         * @return {@code value} converted to a {@code long}.
043         * @throws ArithmeticException
044         *             if the {@code value} will not exactly fit in a {@code long}.
045         * @since JDK 1.8
046         */
047        public static final long bigIntegerToLongValueExact(BigInteger value) {
048                if (value.bitLength() <= 63) return value.longValue();
049                else throw new ArithmeticException("BigInteger out of long range: " + value);
050        }
051
052        // no instances
053        private JDKSupport() {
054        }
055
056}