java 商品评价计算算法

　　

import java.io.Serializable;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.math.BigDecimal;
import java.math.RoundingMode;

/**
 * 商品评价算法
 * 
 * @project  icomment
 * @fileName ProductScore.java
 * @Description
 * @author light-zhang
 * @date 2018年1月15日下午4:44:40
 * @version 1.0.0
 */
public abstract class CommentUtils implements Serializable {
    
    private static final long serialVersionUID = 8143504152635422263L;
    /*************************** 方案一 *******************************************/
    private static final double baby_ratio = 0.837;// 宝贝评价计算占比(0.837/千)
    private static final double merchant_ratio = 0.113;// 卖家态度计算占比(0.113/千)
    private static final double logistics_ratio = 0.0278;// 物流评价计算占比(0.0278/万)
    private static final double aplatfrom_ration = 0.0037;// 平台影响分A(0.0037/万)
    private static final double bplatfrom_ration = 0.0185; // 平台影响分B (0.0185/万)
    private static final double basic_score = 4.7463;// 最高分 
    /**************************************************************************/
    /**
     * 方案一 宝贝占比较高,防止卖假货 宝贝评价 0.837(千分比) 5 卖家态度 0.113(千分比) 4 物流服务 0.0278(万分比) 3 平台影响
     * 0.0037(万分比) 2 平台影响 0.0185(万分比) 1
     * 
     * @return
     */
    public static BigDecimal babyScore(int baby, int merchant, int logistics) {
        double value = baby * baby_ratio + (merchant - 1) * merchant_ratio + (logistics - 2) * logistics_ratio
                + (2 * aplatfrom_ration) + (1 * bplatfrom_ration);
        final BigDecimal result = getTemp(new BigDecimal(value));
        if (result.doubleValue() == basic_score) {
            return result.setScale(0, RoundingMode.HALF_UP);
        }
        return result.setScale(1, RoundingMode.HALF_UP);
    }

    /**************************
     * 方案二
     ************************************************/
    private static final double syn_baby_ratio = 0.35;
    private static final double syn_merchant_ratio = 0.25;
    private static final double syn_logistics_ratio = 0.35;
    private static final double syn_aplatfrom_ration = 0.3;
    private static final double syn_bplatfrom_ration = 0.2;
    private static final double syn_basic_score = 4.6;

    /**************************************************************************/
    /**
     * 综合占比率 
     * @param baby
     * @param merchant
     * @param logistics
     * @return
     */
    public static BigDecimal synthetical(int baby, int merchant, int logistics) {
        double value = baby * syn_baby_ratio + (merchant - 1) * syn_merchant_ratio
                + (logistics - 2) * syn_logistics_ratio + 2 * syn_aplatfrom_ration + 1 * syn_bplatfrom_ration;
        final BigDecimal result = getTemp(new BigDecimal(value));
        if (result.doubleValue() == syn_basic_score) {
            return result.setScale(0, RoundingMode.HALF_UP);
        }
        return result.setScale(1, RoundingMode.HALF_UP);
    }

    /**
     * 宝贝梯度 梯度 0失望 1不满意 2一般 3满意 4惊喜 默认返回3满意
     * 
     * @param avgf
     * @return
     */
    public static int grads(double avgf) {
        return (avgf <= 1.5) ? 0
                : (avgf > 1.5 && avgf <= 2.3) ? 1
                        : (avgf > 2.3 && avgf <= 3.1) ? 2
                                : (avgf > 3.1 && avgf <= 4.0) ? 3 : (avgf > 4.0 && avgf <= 5.0) ? 4 : 3;
    }

    private static <T> T getTemp(T classOfType) {
        ReferenceQueue<T> queue = new ReferenceQueue<T>();
        WeakReference<T> weakRef = new WeakReference<T>(classOfType, queue);
        if (null == weakRef.get()) {
            weakRef = new WeakReference<T>(classOfType);
        }
        return weakRef.get();
    }  
    
    public static void main(String[] args) {
        int baby = 2;
        int merchant = 2;
        int logistics = 5;
        System.out.println("评测1 " + babyScore(baby, merchant, logistics));// 方案一 防止卖假货采用方案
        System.out.println("梯度1 >>>>> " + grads(babyScore(baby, merchant, logistics).doubleValue()));

        System.out.println("评测2 " + synthetical(baby, merchant, logistics));// 方案二 综合商家,宝贝,物流采用方案
        System.out.println("梯度2 >>>>>  " + grads(synthetical(baby, merchant, logistics).doubleValue()));
    } 
}