Java tutorial
/** * Copyright (c) 2010-2015, openHAB.org and others. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html */ package org.openhab.binding.weather.internal.provider; import java.io.ByteArrayInputStream; import java.io.InputStream; import java.util.Calendar; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.HttpVersion; import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager; import org.apache.commons.httpclient.cookie.CookiePolicy; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.params.HttpClientParams; import org.apache.commons.lang.StringUtils; import org.openhab.binding.weather.internal.common.LocationConfig; import org.openhab.binding.weather.internal.common.ProviderConfig; import org.openhab.binding.weather.internal.common.WeatherConfig; import org.openhab.binding.weather.internal.common.WeatherContext; import org.openhab.binding.weather.internal.model.Forecast; import org.openhab.binding.weather.internal.model.ProviderName; import org.openhab.binding.weather.internal.model.Weather; import org.openhab.binding.weather.internal.parser.WeatherParser; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Common base class for all weather providers. Retrieves, parses and returns * weather data. * * @author Gerhard Riegler * @since 1.6.0 */ public abstract class AbstractWeatherProvider implements WeatherProvider { private static final Logger logger = LoggerFactory.getLogger(AbstractWeatherProvider.class); private static HttpClient httpClient = null; private WeatherConfig config = WeatherContext.getInstance().getConfig(); private WeatherParser parser; static { httpClient = new HttpClient(new MultiThreadedHttpConnectionManager()); HttpClientParams params = httpClient.getParams(); params.setConnectionManagerTimeout(15000); params.setSoTimeout(30000); params.setContentCharset("UTF-8"); params.setCookiePolicy(CookiePolicy.IGNORE_COOKIES); params.setVersion(HttpVersion.HTTP_1_0); } public AbstractWeatherProvider(WeatherParser parser) { this.parser = parser; } /** * {@inheritDoc} */ @Override public Weather getWeather(LocationConfig locationConfig) throws Exception { Weather weather = new Weather(getProviderName()); executeRequest(weather, prepareUrl(getWeatherUrl(), locationConfig), locationConfig); String forecastUrl = getForecastUrl(); if (forecastUrl != null && !weather.hasError()) { executeRequest(weather, prepareUrl(forecastUrl, locationConfig), locationConfig); } if (logger.isDebugEnabled()) { logger.debug("{}[{}]: {}", getProviderName(), locationConfig.getLocationId(), weather.toString()); for (Weather fc : weather.getForecast()) { logger.debug("{}[{}]: {}", getProviderName(), locationConfig.getLocationId(), fc.toString()); } } return weather; } /** * Prepares the provider URL by setting the config. */ private String prepareUrl(String url, LocationConfig locationConfig) { ProviderConfig providerConfig = config.getProviderConfig(getProviderName()); if (providerConfig != null) { url = StringUtils.replace(url, "[API_KEY]", providerConfig.getApiKey()); url = StringUtils.replace(url, "[API_KEY_2]", providerConfig.getApiKey2()); } url = StringUtils.replace(url, "[LATITUDE]", locationConfig.getLatitude().toString()); url = StringUtils.replace(url, "[LONGITUDE]", locationConfig.getLongitude().toString()); url = StringUtils.replace(url, "[LANGUAGE]", locationConfig.getLanguage()); return url; } /** * Executes the http request and parses the returned stream. */ private void executeRequest(Weather weather, String url, LocationConfig locationConfig) throws Exception { GetMethod get = null; try { logger.trace("{}[{}]: request : {}", getProviderName(), locationConfig.getLocationId(), url); get = new GetMethod(url); httpClient.executeMethod(get); InputStream is = null; if (logger.isTraceEnabled()) { String response = get.getResponseBodyAsString(100000); response = StringUtils.remove(response, "\n"); response = StringUtils.trim(response); logger.trace("{}[{}]: response: {}", getProviderName(), locationConfig.getLocationId(), response); is = new ByteArrayInputStream(response.getBytes(get.getResponseCharSet())); } else { is = get.getResponseBodyAsStream(); } if (get.getStatusCode() == HttpStatus.SC_OK) { parser.parseInto(is, weather); } // special handling because of bad OpenWeatherMap json structure if (weather.getProvider() == ProviderName.OPENWEATHERMAP && weather.getResponseCode() != null && weather.getResponseCode() == 200) { weather.setError(null); } if (!weather.hasError() && get.getStatusCode() != HttpStatus.SC_OK) { weather.setError(get.getStatusLine().toString()); } if (weather.hasError()) { logger.error("{}[{}]: Can't retreive weather data: {}", getProviderName(), locationConfig.getLocationId(), weather.getError()); } else { setLastUpdate(weather); } } catch (Exception ex) { logger.error(getProviderName() + ": " + ex.getMessage()); weather.setError(ex.getClass().getSimpleName() + ": " + ex.getMessage()); throw ex; } finally { if (get != null) { get.releaseConnection(); } } } /** * Sets the current timestamp in every weather object. */ private void setLastUpdate(Weather weather) { Calendar cal = Calendar.getInstance(); weather.getCondition().setLastUpdate(cal); for (Forecast forecast : weather.getForecast()) { forecast.getCondition().setLastUpdate(cal); } } /** * Returns the provider weather url. */ protected abstract String getWeatherUrl(); /** * Returns the provider forecast url, some providers needs a second http * request. */ protected String getForecastUrl() { return null; } }