表结构

--抽奖设置
create table AWARD_INFO
(ID         NUMBER(11) not null,ACT_ID     NUMBER(11),    --活动IDNUM        NUMBER(11),    --奖品总量（0为不限量）REST       NUMBER(11),    --奖品余量ODDS       NUMBER(11) default 0,    --中奖概率START_DATE DATE,          --开始日期（可为空）END_DATE   DATE,          --结束日期（可为空）PRODUCT_ID NUMBER(11),    --奖品IDSTATE      NUMBER(5) default 0,    --状态 0-有效 1-失效INFO_TYPE  NUMBER(5) default 0     --0-正常
);
alter table AWARD_INFOadd constraint PK_AWARD_INFO primary key (ID);--中奖纪录
create table AWARD_LOG
(id         number(11),    act_id     number(11),    --活动IDget_time   date,    --中奖时间product_id number(11),    --奖品IDnum        number(11) default 1,    --中奖数量person     varchar2(50),    --中奖人info_id    number(11),    --抽奖设置IDstate      number(5)    --状态 0-有效 1-失效
);
alter table AWARD_LOGadd constraint PK_AWARD_LOG primary key (ID);

代码实现

   public static class AwardResult{public int ret;    //返回结果public int logId;  //AWARD_LOG id}/*** 抽奖算法* @param actId 抽奖活动ID* @param person 抽奖人* @param productId 奖品ID -1则为该活动ID下所有奖品* @param excludeId 排除奖品ID -1 则不排除，与productId不能同时>0* @param checkDate 是否检查时间* @return -1 没有抽奖数据；-2 奖品已抽完； -3 其他错误；>=0 中奖productId; -4 排除id* @throws Exception*/public static AwardResult getAwardFull(int actId, String person, int productId, int[] excludeIds, boolean checkDate) throws SQLException{AwardResult result = new AwardResult(); Connection conn = JDBC.getConnection();conn.setAutoCommit(false);try{List<Map<String,Object>> rows;String sql;String checkDateStr = "";String baseSql = "select t.id, t.product_id, t.num, t.rest, t.odds, t.info_type from award_info t where t.act_id=? and t.state=0 ";if(checkDate){checkDateStr = " and t.start_Date <= sysdate and t.end_Date >= sysdate ";}if(productId > 0){//抢购sql = baseSql + " and t.product_id=? " + checkDateStr + " for update";rows = JDBC.getRows(sql, new Object[]{actId, productId}, conn);}else{//活动所有物品抽奖sql = baseSql + checkDateStr + " for update";rows = JDBC.getRows(sql, new Object[]{actId}, conn);}if(rows.isEmpty()){//没有抽奖数据log.info("没有抽奖数据  actId={} person={} productId={} excludeIds={} checkDate={}", actId, person, productId, excludeIds, checkDate);conn.commit();result.ret = -1;return result;}int infoId = -1;int getProductId = -1;int num = -1;int rest = -1;if(rows.size() == 1){//抢购num = ((Number)rows.get(0).get("NUM")).intValue();rest =  ((Number)rows.get(0).get("REST")).intValue();infoId = ((Number)rows.get(0).get("ID")).intValue();getProductId = ((Number)rows.get(0).get("PRODUCT_ID")).intValue();}else{//抽奖int[][] temp = new int[rows.size()][3];int sum = -1;int i = 0;for(int k = 0;  k < rows.size(); k++){//设置奖品池int odds = ((BigDecimal)rows.get(k).get("ODDS")).intValue();sum++;temp[i][0] = sum; //起始值sum = sum + odds;temp[i][1] = sum; //结束值temp[i][2] = k;   //rows indexi++;}//抽奖Random random = new Random();int r = random.nextInt(sum + 1);int j = 0;for(int k = 0; k < i; k++){if(r >= temp[k][0] && r <= temp[k][1]){j = k;break;}}infoId = ((BigDecimal)rows.get(temp[j][2]).get("ID")).intValue();getProductId = ((BigDecimal)rows.get(temp[j][2]).get("PRODUCT_ID")).intValue();num = ((Number)rows.get(temp[j][2]).get("NUM")).intValue();rest = ((Number)rows.get(temp[j][2]).get("REST")).intValue();}//判断是否排除idif(ArrayUtils.contains(excludeIds, getProductId)){log.info("是排除ID  actId={} person={} productId={} excludeIds={} checkDate={}", actId, person, productId, excludeIds, checkDate);conn.commit();result.ret = -4;return result;}//存量不足if(num > 0 && rest <= 0){log.info("奖品已清空  actId={} person={} productId={} excludeIds={} checkDate={}", actId, person, productId, excludeIds, checkDate);JDBC.commit(conn);result.ret = -2;return result;}//更新奖品记录if(num > 0){//非不限量sql = "update award_info set rest = rest - 1 where id = ?";JDBC.update(sql, new Object[]{infoId}, conn);}//记录获奖名单AwardLog log = new AwardLog();log.setActId(actId);log.setNum(1);log.setPerson(person);log.setProductId(getProductId);log.setInfoId(infoId);Number logId = log.save(conn);if(logId == null){throw new SQLException("save award_log error");}result.logId = logId.intValue();conn.commit();result.ret = getProductId;return result;}catch(SQLException e){log.error("getAward error", e);conn.rollback();}finally{JDBC.close(conn);}result.ret = -3;return result;}

应用场景

• 单件奖品抢购（可限时）
• 多件奖品按概率中奖（可限时、可不限量）