ymanv.forex.provider.AProvider.java Source code

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Here is the source code for ymanv.forex.provider.AProvider.java

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/**
 * Copyright (C) 2014 https://github.com/ymanv
 *
 * This software 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.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */
package ymanv.forex.provider;

import java.io.IOException;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import ymanv.forex.http.URLConnectionHandler;
import ymanv.forex.model.entity.rate.RateEntity;

public abstract class AProvider {

    @Autowired
    protected URLConnectionHandler handler;

    protected final static String CURRENCY_NOT_SUPPORTED_MSG = "Currency not supported: {}";

    private static final BigDecimal PRECISION_QUANTITY = new BigDecimal("1000000000");
    private static final BigDecimal ONE = new BigDecimal("1");
    private static final BigDecimal TWO = new BigDecimal("2");

    protected final static String DATE_FORMAT_STRNG = "yyyy-MM-dd";

    /**
     * Returns the latest possible rates value (depending of the implementation).
     * 
     * @return List of latest rates
     * @throws IOException
     */
    public abstract List<RateEntity> getRates() throws IOException;

    protected static BigDecimal divide(BigDecimal dividend, BigDecimal divisor) {
        return dividend.multiply(PRECISION_QUANTITY).divide(divisor, RoundingMode.HALF_UP)
                .divide(PRECISION_QUANTITY);
    }

    protected BigDecimal avg(BigDecimal first, BigDecimal second) {
        return first.add(second).divide(TWO);
    }

    /**
     * Divide 1 by the specified BigDecimal.
     * 
     * @param d
     * @return the divided BigDecimal
     */
    public static BigDecimal invert(BigDecimal d) {
        return divide(ONE, d);
    }

    @Override
    public String toString() {
        return getClass().getSimpleName();
    }
}