SpringBoot+Redis实现查找附近用户的示例代码

redis > GEOADD cities 116.4074 39.9042 Beijing
redis > GEOADD cities NX 121.4737 31.2304 Shanghai

redis > GEORADIUS User-Location 116.4074 39.9042 100 km

/**
 * 更新用户位置信息
 * {
 *     "longitude": 113.936099,
 *     "latitude": 22.542364
 * }
 */
@PostMapping("updateUserLocation")
@ResponseBody
@CrossOrigin
public <T> T updateUserLocation(@RequestBody HashMap<String, Object> data) {
    return userService.updateUserLocation(data);
}

/**
 * 更新用户位置信息
 * {
 *     "longitude": 113.936099,
 *     "latitude": 22.542364,
 *     "radius": 10
 * }
 */
@PostMapping("nearby")
@ResponseBody
@CrossOrigin
public <T> T nearby(@RequestBody HashMap<String, Object> data) {
    return userService.nearby(data);
}

<T> T updateUserLocation(HashMap<String, Object> data);

<T> T nearby(HashMap<String, Object> data);

@Override
public <T> T updateUserLocation(HashMap<String, Object> data) {
    HashMap<String, Object> responseObj = new HashMap<>();
    // 获取登录用户
    UserDTO userDTO = RequestHolder.getUser();

    // 获取经纬度
    Double longitude = (Double) data.get("longitude"); // 经度
    Double latitude = (Double) data.get("latitude"); // 维度

    String USER_LOCATION_KEY = "User-Location";
    String phone = userDTO.getPhone();
    stringRedisTemplate.opsForGeo().add(USER_LOCATION_KEY, new Point(longitude, latitude), phone);
    responseObj.put("code", 200);
    responseObj.put("success", true);
    responseObj.put("msg", "更新完成");
    return (T) responseObj;
}

@Override
public <T> T nearby(HashMap<String, Object> data) {
    HashMap<String, Object> responseObj = new HashMap<>();
    // 获取登录用户
    UserDTO userDTO = RequestHolder.getUser();

    // 获取经纬度，以及半径
    Double longitude = (Double) data.get("longitude"); // 经度
    Double latitude = (Double) data.get("latitude"); // 维度
    Integer radius = (Integer) data.get("radius"); // 半径

    String USER_LOCATION_KEY = "User-Location";
    String phone = userDTO.getPhone();
    Distance distance = new Distance(radius, Metrics.KILOMETERS); // 距离，单位为千米
    Circle circle = new Circle(new Point(longitude, latitude), distance); // 圆心

    // 使用Redis的地理位置操作对象，在指定范围内查询附近的用户位置信息
    GeoResults<RedisGeoCommands.GeoLocation<String>> geoResults = stringRedisTemplate.opsForGeo().radius(USER_LOCATION_KEY, circle);
    List<Object> nearbyUsers = new ArrayList<>();
    for (GeoResult<RedisGeoCommands.GeoLocation<String>> geoResult : geoResults.getContent()) {
        Object memberId = geoResult.getContent().getName();
        // 排除查询用户本身
        if (!memberId.equals(phone)) {
            nearbyUsers.add(memberId);
        }
    }

    responseObj.put("code", 200);
    responseObj.put("success", true);
    responseObj.put("msg", "更新完成");
    responseObj.put("data", nearbyUsers);
    return (T) responseObj;
}