如何改写Java转盘抽奖算法为长尾？

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javapublic class LuckDraw { public int getPrizeIndex(List prizes) throws Exception { int random=-1; // 计算总权重 double sumWeight=0; for (GoodsEntity p : prizes) { sumWeight +=p.getPrizeWeight(); } // 生成随机数 random=(int) (Math.random() * sumWeight); return random; }}

转盘抽奖算法（java）

public class LuckDraw { public int getPrizeIndex(List prizes) throws Exception { int random = -1; //计算总权重 double sumWeight = 0; for (GoodsEntity p : prizes) { sumWeight += p.getPrizeWeight(); } //产生随机数 double randomNumber; randomNumber = Math.random(); //根据随机数在所有奖品分布的区域并确定所抽奖品 double d1 = 0; double d2 = 0; for (int i = 0; i < prizes.size(); i++) { d2 += Double.parseDouble(String.valueOf(prizes.get(i).getPrizeWeight())) / sumWeight; if (i == 0) { d1 = 0; } else { d1 += Double.parseDouble(String.valueOf(prizes.get(i - 1).getPrizeWeight())) / sumWeight; } if (randomNumber > d1 && randomNumber <= d2) { random = i; break; } } return random; } } 实体类

@Entity @Table(name = "goods") public class GoodsEntity { private Long goodsId; private String goodsName; private Byte dataStatus; private Timestamp createTime; private Byte ranking; private Integer prizeWeight; private BigDecimal price; private Integer version; @Id @Column(name = "goods_id", nullable = false) public Long getGoodsId() { return goodsId; } public void setGoodsId(Long goodsId) { this.goodsId = goodsId; } @Basic @Column(name = "goods_name", nullable = true, length = 50) public String getGoodsName() { return goodsName; } public void setGoodsName(String goodsName) { this.goodsName = goodsName; } @Basic @Column(name = "data_status", nullable = true) public Byte getDataStatus() { return dataStatus; } public void setDataStatus(Byte dataStatus) { this.dataStatus = dataStatus; } @Basic @Column(name = "create_time", nullable = false) public Timestamp getCreateTime() { return createTime; } public void setCreateTime(Timestamp createTime) { this.createTime = createTime; } @Basic @Column(name = "ranking", nullable = true) public Byte getRanking() { return ranking; } public void setRanking(Byte ranking) { this.ranking = ranking; } @Basic @Column(name = "prize_weight", nullable = true) public Integer getPrizeWeight() { return prizeWeight; } public void setPrizeWeight(Integer prizeWeight) { this.prizeWeight = prizeWeight; } @Basic @Column(name = "version", nullable = true) public Integer getVersion() { return version; } public void setVersion(Integer version) { this.version = version; } @Basic @Column(name = "price", nullable = true) public BigDecimal getPrice() { return price; } public void setPrice(BigDecimal price) { this.price = price; } } Controller代码

public Map luckDraw() { Map result = new HashMap (); try { List goodsEntityList = goodsService.getGoods();//参与抽奖的商品列表 int selected = luckDraw.getPrizeIndex(goodsEntityList); ResponseGoods responseGoods = new ResponseGoods(); responseGoods.setGoodsName(goodsEntityList.get(selected).getGoodsName()); responseGoods.setPrice(goodsEntityList.get(selected).getPrice()); result.put("result", responseGoods); } catch (Exception e) { e.printStackTrace(); } return result; }