spring.travel.site.services.WeatherService.java Source code

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Here is the source code for spring.travel.site.services.WeatherService.java

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/**
 * Copyright 2014 Andy Godwin
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package spring.travel.site.services;

import com.fasterxml.jackson.core.type.TypeReference;
import com.google.common.cache.Cache;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import spring.travel.site.model.weather.DailyForecast;
import spring.travel.site.model.weather.Location;

import java.util.Optional;
import java.util.concurrent.CompletableFuture;

import static uk.co.sdev.async.Futures.some;
import static uk.co.sdev.async.Futures.withFallback;

@Service
public class WeatherService {

    @Autowired
    private HttpClient client;

    @Autowired
    private Cache<String, DailyForecast> weatherCache;

    @Value("${weather.service.url}")
    private String weatherServiceUrl;

    public CompletableFuture<Optional<DailyForecast>> forecast(Location location, int numberOfDays) {
        String url = url(location.getCityId(), numberOfDays);

        DailyForecast dailyForecast = weatherCache.getIfPresent(url);
        if (dailyForecast != null) {
            return some(dailyForecast);
        }

        return client.get(url, new TypeReference<Optional<DailyForecast>>() {
        }).handle(withFallback(Optional.<DailyForecast>empty()))
                .whenComplete((result, t) -> result.ifPresent(r -> weatherCache.put(url, r)));
    }

    private String url(int cityId, int numberOfDays) {
        return new StringBuilder(weatherServiceUrl).append("?id=").append(cityId).append("&cnt=")
                .append(numberOfDays).append("&mode=json").toString();
    }
}