多个redis有序集合组合如何实现分页

多个redis有序集合组合如何实现分页

  需求：现在将不同类别的数据放入不同的redis有序集合key中，查询的时候不区分类别，进行统一的查询。

redis分页实体：

import java.io.Serializable;/** * 中间过滤实体<br>  * 〈功能详细描述〉 * * @author wangmuming * @see [相关类/方法]（可选） * @since [产品/模块版本] （可选） */public class RedisPaging implements Serializable {    /**     */    private static final long serialVersionUID = 8028303213452701294L;        private String key;        private long total;        private int offset;        private int limit;    /**     * @return the key     */    public String getKey() {        return key;    }    /**     * @param key the key to set     */    public void setKey(String key) {        this.key = key;    }            /**     * @return the total     */    public long getTotal() {        return total;    }    /**     * @param total the total to set     */    public void setTotal(long total) {        this.total = total;    }    /**     * @return the offset     */    public int getOffset() {        return offset;    }    /**     * @param offset the offset to set     */    public void setOffset(int offset) {        this.offset = offset;    }    /**     * @return the limit     */    public int getLimit() {        return limit;    }    /**     * @param limit the limit to set     */    public void setLimit(int limit) {        this.limit = limit;    }    /* (non-Javadoc)     * @see java.lang.Object#toString()     */    @Override    public String toString() {        return "RedisPaging [key=" + key + ", total=" + total + ", offset=" + offset + ", limit=" + limit + "]";    }    }

查询方法内的内容：

 //使用linkedhashmap 作为有序集合返回json        Map<String,Object> map = new LinkedHashMap<String,Object>();        map.put("start", page);        map.put("draw", draw);        try {                        String[] keys = key.split(",");            if( keys.length == 1 ) {                // 获取redis 统计信息                long total = RedisUtil.zcard(key);                int offset = page; //分页从0开始//                long pagesize = (total % count) == 0 ? total /count : (total /count)+1;                if(offset <= total) {                    List<String> list = RedisUtil.zrangeByScore(key, sort, offset, count);                    List<OrderlinkAlert> objList = new ArrayList<OrderlinkAlert>();                    OrderlinkAlert obj = null;                    long index = offset + 1l;                    for (String string : list) {                        obj = new OrderlinkAlert();                        obj.setId(index);                        obj.setOrderItemId(string);                        Double time = RedisUtil.zscore(key, string);                        long efficateTime = 0l;                        if( null != time ) {                            efficateTime = time.longValue();                        }                        obj.setExceedRange(DateUtil.formatTime(efficateTime));                        objList.add(obj);                        index++;                    }                    map.put("data", objList);                    map.put("recordsTotal", total);                    map.put("recordsFiltered", total);                    //map.put("page", pagesize);                    map.put("length", count);                }            } else { //并行路径的请求情况                                // 获取redis 统计信息                long total = 0l;                //将多个key值从存储到list中                List<RedisPaging> keyList = new ArrayList<RedisPaging>();                RedisPaging paging = null;                for (String string : keys) {                    long tmp = RedisUtil.zcard(string);                    total = total + tmp;                    paging = new RedisPaging();                    paging.setKey(string);                    paging.setTotal(tmp);                    keyList.add(paging);                }                int offset = page; //分页从0开始//                long pagesize = (total % count) == 0 ? total /count : (total /count)+1;                if(offset <= total) {                    //计算每个key里面去哪些数据                     keyList = computeRedisPaging(keyList,offset,count,total);                                      Map<String,String> mapping = new LinkedHashMap<String,String>();                    // 多个key值存在的逻辑                    for (RedisPaging redisPaging : keyList) {                        List<String> list = RedisUtil.zrangeByScore(redisPaging.getKey(), sort, redisPaging.getOffset(), redisPaging.getLimit());                        if( null != list && !list.isEmpty() ) {                            for (String string : list) {                                Double time = RedisUtil.zscore(redisPaging.getKey(), string);                                long efficateTime = 0l;                                if( null != time ) {                                    efficateTime = time.longValue();                                }                                mapping.put(string, DateUtil.formatTime(efficateTime));                            }                        }                    }                    List<OrderlinkAlert> objList = new ArrayList<OrderlinkAlert>();                    OrderlinkAlert obj = null;                    long index = offset + 1l;                    for (Map.Entry<String,String> entity : mapping.entrySet()) {                        obj = new OrderlinkAlert();                        obj.setId(index);                        obj.setOrderItemId(entity.getKey());                        obj.setExceedRange(entity.getValue());                        objList.add(obj);                        index++;                    }                    map.put("data", objList);                    map.put("recordsTotal", total);                    map.put("recordsFiltered", total);                    //map.put("page", pagesize);                    map.put("length", count);                }                            }                  } catch (Exception e) {            logger.error("query redis data error:", e);            throw new Exception(e);        }        

redis 多有序集合分页逻辑的实现：

 private List<RedisPaging> computeRedisPaging(List<RedisPaging> keyList, int offset, int count, long total) {        //当前需要获取的记录数        long sum = 0;        int indexStart = 0;        int indexEnd = 0;        //计算出两个值 大于 等于 offset  小于等于 offset + count+1的位置        for(int i=0;i<keyList.size();i++) {            sum = sum + keyList.get(i).getTotal();            if( sum >= (offset) ) {                indexStart = i;                break;            }        }        sum = 0;        for(int i=0;i<keyList.size();i++) {            sum = sum + keyList.get(i).getTotal();            if( i >= indexStart && sum >= (offset+count) ) {                indexEnd = i;                break;            } else if (i >= indexStart && i == (keyList.size()-1)  && sum >= offset && sum <= (offset+count)) {                indexEnd = i;                break;            }                       }        //        System.out.println("indexStart :"+indexStart + " indexEnd :"+ indexEnd);        //如果只存在一个 取全部数据        if( indexStart == indexEnd ) {            RedisPaging paging = keyList.get(indexStart);            long t = 0l;            for(int i=0;i<indexStart;i++) {                t = t + keyList.get(i).getTotal();            }            paging.setOffset(offset-(int)t);            paging.setLimit(count);            keyList.clear();            keyList.add(paging);        }                //如果只存在2个 分开去数据 计算第一个 - offset  从第二个里面补剩下的数据        if( (indexEnd-indexStart) == 1 ) {            RedisPaging paging0 = keyList.get(indexStart);            long t = 0l;            for(int i=0;i<indexStart;i++) {                t = t + keyList.get(i).getTotal();            }            long rest0 = offset - t;            paging0.setOffset((int)rest0);            paging0.setLimit((int) (paging0.getTotal()-rest0));            RedisPaging paging1 = keyList.get(indexEnd);            paging1.setOffset(0);            paging1.setLimit((int) (count-(paging0.getTotal()-rest0)));            keyList.clear();            if( paging0.getTotal() > 0 ) {                keyList.add(paging0);            }            if( paging1.getTotal() >0 ) {                keyList.add(paging1);            }                    }                //如果大于等于3 中间的去所有的 开头 和 结束 计算取多少        if( (indexEnd-indexStart) >= 2 ) {            List<RedisPaging> tmp = new ArrayList<RedisPaging>();            tmp.addAll(keyList);            keyList.clear();                        long t = 0l;            for(int i=0;i<indexStart;i++) {                t = t + tmp.get(i).getTotal();            }            long rest0 = offset - t;                        RedisPaging pagingStart = tmp.get(indexStart);            pagingStart.setOffset((int)rest0);            pagingStart.setLimit((int) (pagingStart.getTotal() - rest0 ));            if (pagingStart.getTotal() > 0 ) {                keyList.add(pagingStart);            }            rest0 = pagingStart.getTotal() - rest0 ;            for(int i=(indexStart+1);i<indexEnd;i++) {                RedisPaging paging = tmp.get(i);                paging.setOffset(0);                paging.setLimit((int)tmp.get(i).getTotal());                rest0 = rest0 + tmp.get(i).getTotal();                if (paging.getTotal() > 0 ) {                    keyList.add(paging);                }            }            RedisPaging pagingTop = tmp.get(indexEnd);            pagingTop.setOffset(0);            pagingTop.setLimit((int) (count-rest0));            if (pagingTop.getTotal() > 0 ) {                keyList.add(pagingTop);            }        }                return keyList;    }