Android Long Overflow Check addAndCheck(long a, long b)

Here you can find the source of addAndCheck(long a, long b)

Description

Add two long integers, checking for overflow.

License

Apache License

Parameter

Parameter Description
a an addend
b an addend

Exception

Parameter Description
MathArithmeticException if the result can not be represented as anlong

Return

the sum a+b

Declaration

public static long addAndCheck(long a, long b)
        throws MathArithmeticException 

Method Source Code

/*// ww  w  . j  a  v a 2s  .  c o m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.math.BigInteger;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.commons.math3.exception.MathArithmeticException;
import org.apache.commons.math3.exception.NotPositiveException;
import org.apache.commons.math3.exception.NumberIsTooLargeException;
import org.apache.commons.math3.exception.util.Localizable;
import org.apache.commons.math3.exception.util.LocalizedFormats;

public class Main{
    /**
     * Add two integers, checking for overflow.
     *
     * @param x an addend
     * @param y an addend
     * @return the sum {@code x+y}
     * @throws MathArithmeticException if the result can not be represented
     * as an {@code int}.
     * @since 1.1
     */
    public static int addAndCheck(int x, int y)
            throws MathArithmeticException {
        long s = (long) x + (long) y;
        if (s < Integer.MIN_VALUE || s > Integer.MAX_VALUE) {
            throw new MathArithmeticException(
                    LocalizedFormats.OVERFLOW_IN_ADDITION, x, y);
        }
        return (int) s;
    }
    /**
     * Add two long integers, checking for overflow.
     *
     * @param a an addend
     * @param b an addend
     * @return the sum {@code a+b}
     * @throws MathArithmeticException if the result can not be represented as an
     *         long
     * @since 1.2
     */
    public static long addAndCheck(long a, long b)
            throws MathArithmeticException {
        return ArithmeticUtils.addAndCheck(a, b,
                LocalizedFormats.OVERFLOW_IN_ADDITION);
    }
    /**
     * Add two long integers, checking for overflow.
     *
     * @param a Addend.
     * @param b Addend.
     * @param pattern Pattern to use for any thrown exception.
     * @return the sum {@code a + b}.
     * @throws MathArithmeticException if the result cannot be represented
     * as a {@code long}.
     * @since 1.2
     */
    private static long addAndCheck(long a, long b, Localizable pattern)
            throws MathArithmeticException {
        long ret;
        if (a > b) {
            // use symmetry to reduce boundary cases
            ret = addAndCheck(b, a, pattern);
        } else {
            // assert a <= b

            if (a < 0) {
                if (b < 0) {
                    // check for negative overflow
                    if (Long.MIN_VALUE - b <= a) {
                        ret = a + b;
                    } else {
                        throw new MathArithmeticException(pattern, a, b);
                    }
                } else {
                    // opposite sign addition is always safe
                    ret = a + b;
                }
            } else {
                // assert a >= 0
                // assert b >= 0

                // check for positive overflow
                if (a <= Long.MAX_VALUE - b) {
                    ret = a + b;
                } else {
                    throw new MathArithmeticException(pattern, a, b);
                }
            }
        }
        return ret;
    }
}

Related

  1. addAndCheck(long a, long b, Localizable pattern)
  2. mulAndCheck(long a, long b)
  3. subAndCheck(long a, long b)