程序员的量化交易之路（28）--Cointrader之Offer报价实体（15）

转载须注明出处：http://blog.csdn.net/minimicall?viewmode=contents，http://cloudtrade.top/

Offer:报价。

bid：买方报价

ask:卖方报价

很简单的一个类。是PriceData的子类。还记得PriceData有什么吧。

时间戳、量、价，

而PriceData又是MarketData的子类，MarketData封装了Market。Market包含市场数据，Exchange,Listing，priceBasis，volumeBasis等。

package org.cryptocoinpartners.schema;

import org.joda.time.Instant;

import javax.persistence.Entity;
import javax.persistence.Transient;

/**
 * Offers represent a bid or ask, usually from a Book.  Asks are represented by using a negative volumeCount
 *
 * @author Tim Olson
 */
@Entity
public class Offer extends PriceData {

    /** same as new Offer() */
    public static Offer bid(Market market, Instant time, Instant timeReceived, Long priceCount, Long volumeCount) {
        return new Offer( market, time, timeReceived, priceCount, volumeCount );
    }

    /** same as new Offer() except the volumeCount is negated */
    public static Offer ask(Market market, Instant time, Instant timeReceived, Long priceCount, Long volumeCount) {
        return new Offer( market, time, timeReceived, priceCount, -volumeCount );
    }

    public Offer(Market market, Instant time, Instant timeReceived, Long priceCount, Long volumeCount) {
        super(time, timeReceived, null, market, priceCount, volumeCount);
    }

    @Override
    public String toString() {
        return "Offer{" +
                       ", market=" + getMarket() +
                       ", priceCount=" + getPriceCount() +
                       ", volumeCount=" + getVolumeCount() +
                       '}';
    }

    @SuppressWarnings("ConstantConditions")
    @Transient
    public Side getSide() { return getVolumeCount() >= 0 ? Side.BUY : Side.SELL; }

    // JPA
    protected Offer() {}

}