package com.karle.redis.biz;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.stereotype.Service;
import com.alibaba.fastjson.JSONObject;
import com.karle.redis.dao.RedisDao;
import com.karle.redis.vo.NearbyBO;
import com.karle.redis.vo.NearbyPO;
import com.karle.redis.vo.Result;
/**
* 博客:http://csdn.karle.vip/
*
* @author Karle
*
*/
@Service
public class NearbyBiz {
/** 2017-09-01 毫秒值/1000 (秒) **/
private static final int BASE_SORT_NUM = 1504195200;
/** 最大距离 **/
private static final int MAX_DISTANCE = 3000;
/** 8小时(秒) **/
private static final int EIGHT_HOUR_SECOND = 60 * 60 * 8;
/** 附近的人缓存key值,p1-城市编号,p2-地区编号 **/
private static final String NEARBY_CACHE_KEY = "nearby_%s_%s";
/** 附近的人用户缓存key值,p1-城市编号,p2-地区编号,p3-用户id **/
private static final String NEARBY_USER_CACHE_KEY = "nearby_user_%s_%s_%s";
@Autowired
private RedisDao redisDao;
// 线程池
@Autowired
private ThreadPoolTaskExecutor threadPoolTaskExecutor;
// 附近的人最新版
public Result<List<NearbyBO>> nearbyNew(NearbyPO paramObj) {
// 缓存key值
String cacheKey = String.format(NEARBY_CACHE_KEY, paramObj.getCityCode(), paramObj.getAdCode());
long currentTimeMillis = System.currentTimeMillis();
// 设置当前用户缓存时间
paramObj.setSaveTime(currentTimeMillis);
// 使用hash更加快速的定位到用户缓存信息,便于删除更新
redisDao.hset(cacheKey, paramObj.getId() + "", JSONObject.toJSONString(paramObj));
// 从当前地区缓存中获取全部用户(包括用户自己)
Map<String, String> cacheAll = redisDao.hGetAll(cacheKey);
if (cacheAll.isEmpty() || cacheAll.size() == 1) {
return new Result<List<NearbyBO>>(true, new ArrayList<>());
}
// 结果集,-1是要排除用户自己
List<NearbyBO> result = new ArrayList<NearbyBO>(cacheAll.size() - 1);
for (String item : cacheAll.keySet()) {
NearbyPO cacheData = JSONObject.parseObject(cacheAll.get(item), NearbyPO.class);
// 计算缓存时长
long twoDayMinute = (cacheData.getSaveTime() - currentTimeMillis) / 60000;
// 八小时有效
if (twoDayMinute > 480) {
// 被动触发删除过期缓存
redisDao.hdel(cacheKey, paramObj.getId() + "");
continue;
}
// 排除用户自己
if (paramObj.getId().equals(cacheData.getId())) {
continue;
}
double distance = countDistance(paramObj.getLongitude(), paramObj.getLatitude(), cacheData.getLongitude(),
cacheData.getLatitude());
// 10KM之内有效
if (distance > 10000) {
continue;
}
result.add(new NearbyBO(cacheData.getId(), cacheData.getName(), distance));
}
return new Result<List<NearbyBO>>(true, result);
}
// 附近的人
@Deprecated
public Result<List<NearbyBO>> nearby(NearbyPO paramObj) {
int nowSortNum = (int) (new Date().getTime() / 1000);
// 此处仅为了减低排序的序号( 获取缓存集合最大排序下标)
int endIndex = nowSortNum - BASE_SORT_NUM;
// 缓存key值
String cacheKey = String.format(NEARBY_CACHE_KEY, paramObj.getCityCode(), paramObj.getAdCode());
// 取同一城市地区&&八小时区间范围数据(八小时之前缓存数据会删除)
Set<String> redisNearby = redisDao.getSetByKeyAndScore(cacheKey, endIndex - EIGHT_HOUR_SECOND, endIndex);
// 开启新线程写入数据(让主线程“专心”处理主业务)
threadPoolTaskExecutor.execute(new InsertCache(paramObj, cacheKey, endIndex));
if (redisNearby.size() == 0)
return new Result<List<NearbyBO>>(false, "附近查无用户", null);
List<NearbyBO> result = new ArrayList<NearbyBO>(redisNearby.size());
boolean oneself = true;
for (String item : redisNearby) {
NearbyPO cacheNearby = JSONObject.parseObject(item, NearbyPO.class);
// 缓存里可能有用户自己
if (cacheNearby.getId().intValue() == paramObj.getId())
continue;
double distance = countDistance(paramObj.getLongitude(), paramObj.getLatitude(), cacheNearby.getLongitude(),
cacheNearby.getLatitude());
// 大于限定距离
if (distance > MAX_DISTANCE)
continue;
result.add(new NearbyBO(cacheNearby.getId(), cacheNearby.getName(), distance));
oneself = false;
}
if (oneself)
return new Result<List<NearbyBO>>(false, "附近查无用户", null);
return new Result<List<NearbyBO>>(true, "获取成功", result);
}
// 把用户定位信息写入缓存
private class InsertCache implements Runnable {
// 用户提交的最新坐标信息
private NearbyPO paramObj;
// “附近的人”缓存集合key
private String cacheKey;
// 获取缓存集合最大排序下标
private Integer endIndex;
public InsertCache(NearbyPO paramObj, String cacheKey, Integer endIndex) {
this.paramObj = paramObj;
this.cacheKey = cacheKey;
this.endIndex = endIndex;
}
@Override
public void run() {
String userCacheKey = String.format(NEARBY_USER_CACHE_KEY, paramObj.getCityCode(), paramObj.getAdCode(),
paramObj.getId());
String cacheNewData = JSONObject.toJSONString(paramObj);
String cacheUserPosition = redisDao.getOneStringByKey(userCacheKey);
// 确保用户坐标信息缓存清除慢于“附近的人”坐标信息
redisDao.setOneStringByKey(userCacheKey, cacheNewData, EIGHT_HOUR_SECOND + 60);
// 保存用户坐标信息至“附近的人”缓存集合
redisDao.addOneStringToZSet(cacheKey, cacheNewData, cacheUserPosition, endIndex);
}
}
/**
* 计算两经纬度点之间的距离(单位:米)
*
* @param longitude1
* 坐标1经度
* @param latitude1
* 坐标1纬度
* @param longitude2
* 坐标2经度
* @param latitude2
* 坐标1纬度
* @return
*/
private static double countDistance(double longitude1, double latitude1, double longitude2, double latitude2) {
double radLat1 = Math.toRadians(latitude1);
double radLat2 = Math.toRadians(latitude2);
double a = radLat1 - radLat2;
double b = Math.toRadians(longitude1) - Math.toRadians(longitude2);
double s = 2 * Math.asin(Math.sqrt(
Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
s = s * 6378137.0;
s = Math.round(s * 10000) / 10000;
return s;
}
}