用redis实现一个投票（java版）

代码

import java.util.*;import redis.clients.jedis.Jedis;import redis.clients.jedis.ZParams;public class Vote {    private static final int ONE_WEEK_IN_SECONDS = 7 * 86400;    private static final int VOTE_SCORE = 432;    private static final int ARTICLES_PER_PAGE = 25;    public String postArticle(Jedis conn,String user,String title,String link){//发表文章        String articleId=String.valueOf(conn.incr("article:"));//自动匹配一个文章id号        String voted="voted:"+articleId;        conn.sadd(voted, user);  //表示该用户已为这篇文章投票。        conn.expire(voted, ONE_WEEK_IN_SECONDS);//给这篇文章设定投票期限        long now=System.currentTimeMillis()/1000;        String article="article:"+articleId;        HashMap<String, String> articleData=new HashMap<>();//对文章的信息进行封装        articleData.put("title",title);        articleData.put("link", link);        articleData.put("user", user);        articleData.put("now", String.valueOf(now));        articleData.put("votes", "1");        articleData.put("againsts", "0");        conn.hmset(article, articleData);//hmset用于同时将多个键值对存储于一个哈希表内        conn.zadd("score:", now+VOTE_SCORE,article);//将文章添加到根据评分排序的有序集合        conn.zadd("time:", now, article);//将文章添加到根据时间排序的有序集合中        return articleId;    }    public void articleVote(Jedis conn,String user,String article,boolean against){//投票或者投反对票        long cutoff=(System.currentTimeMillis()/1000);//        if(conn.zscore("time:", article)+ONE_WEEK_IN_SECONDS<cutoff){//判读文章是否过期            return;        }        String articleId=article.substring(article.indexOf(":")+1);        if(against){ //投反对票            if(conn.sadd("against:"+articleId, user)==1){                conn.hincrBy(article, "against", 1);  //给反对票数组自增1            }        }        else if(conn.sadd("voted:"+articleId, user)==1){//判读该用户是否对这篇文章投过票            conn.zincrby("score:", VOTE_SCORE, article);//为score：表中的article自增分数            conn.hincrBy(article, "votes", 1);//为article:表中"votes"自增1        }    }    public void addGroups(Jedis conn,String articleId,String[] toAdd){        String article="article:"+articleId;        for(String group:toAdd){            conn.sadd("group:"+group, article);        }    }    public void removeGroups(Jedis conn,String articleId,String[] toRemove){        String article="article:"+articleId;        for(String group:toRemove){            conn.srem("group:"+group, article);        }    }    public List<Map<String, String>> getArticles(Jedis conn,int page){        return getArticles(conn, page, "score:");    }    public List<Map<String, String>> getArticles(Jedis conn,int page,String order){//根据页数和排序方式返回所有文章        int start=(page-1)*ARTICLES_PER_PAGE;        int end=start+ARTICLES_PER_PAGE-1;        Set<String> ids=conn.zrevrange(order, start, end);//获取从大到小的顺序的集合        List<Map<String, String>> articles=new ArrayList<>();        for(String id:ids){            Map<String, String> articleData=conn.hgetAll(id);            articleData.put("id", id);            articles.add(articleData);          }        return articles;    }    public List<Map<String, String>> getGroupArticles(Jedis conn,String group,int page){        return getGroupArticles(conn, group, page, "score:");    }    public List<Map<String, String>> getGroupArticles(Jedis conn,String group,int page,String order){        String key=order+group;        if(!conn.exists(key)){            ZParams params=new ZParams().aggregate(ZParams.Aggregate.MAX);            conn.zinterstore(key, params,"group:"+group,order);            conn.expire(key, 60);                                            }        return getArticles(conn, page, key);    }    private void printArticles(List<Map<String, String>> articles){        for(Map<String, String> article:articles){            System.out.println("  id: "+article.get("id"));            for(Map.Entry<String, String> entry:article.entrySet()){                if(entry.getKey().equals("id"))                    continue;                System.out.println("    "+entry.getKey()+": "+entry.getValue());            }               }    }}