Java tutorial
/* * Copyright (C) 2013 The CyanogenMod Project * * 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 com.phonemetra.lockclock.weather; import android.content.Context; import android.location.Location; import android.net.Uri; import android.text.Html; import android.text.TextUtils; import android.util.Log; import com.phonemetra.lockclock.weather.WeatherInfo.DayForecast; import com.phonemetra.lockclock.R; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.xml.sax.Attributes; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; import java.io.IOException; import java.io.StringReader; import java.util.ArrayList; import java.util.List; import java.util.Locale; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; public class YahooWeatherProvider implements WeatherProvider { private static final String TAG = "YahooWeatherProvider"; private static final String URL_WEATHER = "http://weather.yahooapis.com/forecastrss?w=%s&u=%s"; private static final String URL_LOCATION = "http://query.yahooapis.com/v1/public/yql?format=json&q=" + Uri.encode("select woeid, postal, admin1, admin2, admin3, " + "locality1, locality2, country from geo.places where " + "(placetype = 7 or placetype = 8 or placetype = 9 " + "or placetype = 10 or placetype = 11 or placetype = 20) and text ="); private static final String URL_PLACEFINDER = "http://query.yahooapis.com/v1/public/yql?format=json&q=" + Uri.encode("select woeid, city, neighborhood, county from geo.placefinder where " + "gflags=\"R\" and text ="); private static final String[] LOCALITY_NAMES = new String[] { "locality1", "locality2", "admin3", "admin2", "admin1" }; private static final String[] PLACE_NAMES = new String[] { "city", "neigborhood", "county" }; private Context mContext; public YahooWeatherProvider(Context context) { mContext = context; } @Override public int getNameResourceId() { return R.string.weather_source_yahoo; } @Override public List<LocationResult> getLocations(String input) { String language = getLanguage(); String params = "\"" + input + "\" and lang = \"" + language + "\""; String url = URL_LOCATION + Uri.encode(params); JSONObject jsonResults = fetchResults(url); if (jsonResults == null) { return null; } try { JSONArray places = jsonResults.optJSONArray("place"); if (places == null) { // Yahoo returns an object instead of an array when there's only one result places = new JSONArray(); places.put(jsonResults.getJSONObject("place")); } ArrayList<LocationResult> results = new ArrayList<LocationResult>(); for (int i = 0; i < places.length(); i++) { LocationResult result = parsePlace(places.getJSONObject(i)); if (result != null) { results.add(result); } } return results; } catch (JSONException e) { Log.e(TAG, "Received malformed places data (input=" + input + ", lang=" + language + ")", e); } return null; } @Override public WeatherInfo getWeatherInfo(String id, String localizedCityName, boolean metric) { String url = String.format(URL_WEATHER, id, metric ? "c" : "f"); String response = HttpRetriever.retrieve(url); if (response == null) { return null; } SAXParserFactory factory = SAXParserFactory.newInstance(); try { SAXParser parser = factory.newSAXParser(); StringReader reader = new StringReader(response); WeatherHandler handler = new WeatherHandler(); parser.parse(new InputSource(reader), handler); if (handler.isComplete()) { // There are cases where the current condition is unknown, but the forecast // is not - using the (inaccurate) forecast is probably better than showing // the question mark if (handler.conditionCode == 3200) { handler.condition = handler.forecasts.get(0).condition; handler.conditionCode = handler.forecasts.get(0).conditionCode; } WeatherInfo w = new WeatherInfo(mContext, id, localizedCityName != null ? localizedCityName : handler.city, handler.condition, handler.conditionCode, handler.temperature, handler.temperatureUnit, handler.humidity, handler.windSpeed, handler.windDirection, handler.speedUnit, handler.forecasts, System.currentTimeMillis()); Log.d(TAG, "Weather updated: " + w); return w; } else { Log.w(TAG, "Received incomplete weather XML (id=" + id + ")"); } } catch (ParserConfigurationException e) { Log.e(TAG, "Could not create XML parser", e); } catch (SAXException e) { Log.e(TAG, "Could not parse weather XML (id=" + id + ")", e); } catch (IOException e) { Log.e(TAG, "Could not parse weather XML (id=" + id + ")", e); } return null; } private static class WeatherHandler extends DefaultHandler { String city; String temperatureUnit, speedUnit; int windDirection, conditionCode; float humidity, temperature, windSpeed; String condition; ArrayList<DayForecast> forecasts = new ArrayList<DayForecast>(); @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { if (qName.equals("yweather:location")) { city = attributes.getValue("city"); } else if (qName.equals("yweather:units")) { temperatureUnit = attributes.getValue("temperature"); speedUnit = attributes.getValue("speed"); } else if (qName.equals("yweather:wind")) { windDirection = (int) stringToFloat(attributes.getValue("direction"), -1); windSpeed = stringToFloat(attributes.getValue("speed"), -1); } else if (qName.equals("yweather:atmosphere")) { humidity = stringToFloat(attributes.getValue("humidity"), -1); } else if (qName.equals("yweather:condition")) { condition = attributes.getValue("text"); conditionCode = (int) stringToFloat(attributes.getValue("code"), -1); temperature = stringToFloat(attributes.getValue("temp"), Float.NaN); } else if (qName.equals("yweather:forecast")) { DayForecast day = new DayForecast(/* low */ stringToFloat(attributes.getValue("low"), Float.NaN), /* high */ stringToFloat(attributes.getValue("high"), Float.NaN), /* condition */ attributes.getValue("text"), /* conditionCode */ (int) stringToFloat(attributes.getValue("code"), -1)); if (!Float.isNaN(day.low) && !Float.isNaN(day.high) && day.conditionCode >= 0) { forecasts.add(day); } } } public boolean isComplete() { return temperatureUnit != null && speedUnit != null && conditionCode >= 0 && !Float.isNaN(temperature) && !forecasts.isEmpty(); } private float stringToFloat(String value, float defaultValue) { try { if (value != null) { return Float.parseFloat(value); } } catch (NumberFormatException e) { // fall through to the return line below } return defaultValue; } } @Override public WeatherInfo getWeatherInfo(Location location, boolean metric) { String language = getLanguage(); String params = String.format(Locale.US, "\"%f %f\" and locale=\"%s\"", location.getLatitude(), location.getLongitude(), language); String url = URL_PLACEFINDER + Uri.encode(params); JSONObject results = fetchResults(url); if (results == null) { return null; } try { JSONObject result = results.getJSONObject("Result"); String woeid = result.getString("woeid"); String city = null; for (String name : PLACE_NAMES) { if (!result.isNull(name)) { city = result.getString(name); if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, String.format(Locale.US, "Placefinder for location %f %f " + "matched %s using %s", location.getLatitude(), location.getLongitude(), city, name)); } break; } } // The city name in the placefinder result is HTML encoded :-( if (city != null) { city = Html.fromHtml(city).toString(); } else { Log.w(TAG, "Can not resolve place name for " + location); } Log.d(TAG, "Resolved location " + location + " to " + city + " (" + woeid + ")"); WeatherInfo info = getWeatherInfo(woeid, city, metric); if (info != null) { return info; } } catch (JSONException e) { Log.e(TAG, "Received malformed placefinder data (location=" + location + ", lang=" + language + ")", e); } return null; } private LocationResult parsePlace(JSONObject place) throws JSONException { LocationResult result = new LocationResult(); JSONObject country = place.getJSONObject("country"); result.id = place.getString("woeid"); result.country = country.getString("content"); result.countryId = country.getString("code"); if (!place.isNull("postal")) { result.postal = place.getJSONObject("postal").getString("content"); } for (String name : LOCALITY_NAMES) { if (!place.isNull(name)) { result.city = place.getJSONObject(name).getString("content"); break; } } if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "JSON data " + place.toString() + " -> id=" + result.id + ", city=" + result.city + ", country=" + result.countryId); } if (result.id == null || result.city == null || result.countryId == null) { return null; } return result; } private JSONObject fetchResults(String url) { String response = HttpRetriever.retrieve(url); if (response == null) { return null; } if (Log.isLoggable(TAG, Log.VERBOSE)) { Log.v(TAG, "Request URL is " + url + ", response is " + response); } try { JSONObject rootObject = new JSONObject(response); return rootObject.getJSONObject("query").getJSONObject("results"); } catch (JSONException e) { Log.w(TAG, "Received malformed places data (url=" + url + ")", e); } return null; } private String getLanguage() { Locale locale = mContext.getResources().getConfiguration().locale; String country = locale.getCountry(); String language = locale.getLanguage(); if (TextUtils.isEmpty(country)) { return language; } return language + "-" + country; } }