org.javamoney.moneta.function.Reciprocal Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of moneta-bp Show documentation

JSR 354 provides an API for representing, transporting, and performing comprehensive calculations with Money and Currency. This module implements JSR 354.

There is a newer version: 1.4.1

Show newest version

/**
 * Copyright (c) 2012, 2014, Credit Suisse (Anatole Tresch), Werner Keil and others by the @author tag.
 *
 * Licensed 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.
 */
package org.javamoney.moneta.function;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Objects;

import javax.money.MonetaryAmount;
import javax.money.MonetaryOperator;
import javax.money.NumberValue;

/**
 * This class allows to extract the reciprocal value (multiplicative inversion)
 * of a {@link MonetaryAmount} instance.
 *
 * @author Anatole Tresch
 */
final class Reciprocal implements MonetaryOperator{


    /**
     * Access the shared instance of {@link Reciprocal} for use.
     */
    Reciprocal(){
    }


    /**
     * Gets the amount as reciprocal / multiplicative inversed value (1/n).
     * 
     * E.g. 'EUR 2.0' will be converted to 'EUR 0.5'.
     *
     * @return the reciprocal / multiplicative inversed of the amount
     * @throws ArithmeticException if the arithmetic operation failed
     */
    @Override
    public MonetaryAmount apply(MonetaryAmount amount){
        Objects.requireNonNull(amount, "Amount required.");
        NumberValue num = amount.getNumber();
        BigDecimal one = new BigDecimal("1.0").setScale(num.getScale() < 5 ? 5 : num.getScale(), RoundingMode.HALF_EVEN);
        return amount.getFactory().setNumber(one.divide(num.numberValue(BigDecimal.class), RoundingMode.HALF_EVEN))
                .create();
    }

}