/*
* Weather API.
* Copyright (C) 2010 Denis Nelubin aka Gelin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* http://gelin.ru
* mailto:den@gelin.ru
*/
package ru.gelin.android.weather.v_0_2.google;
import java.io.IOException;
import java.io.Reader;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import ru.gelin.android.weather.v_0_2.*;
/**
* Weather, provided by Google API.
*/
public class GoogleWeather implements Weather {
/** Format for dates in the XML */
static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");
/** Format for times in the XML */
static final SimpleDateFormat TIME_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z");
Location location = new SimpleLocation("");
Date date = new Date(0);
Date time = new Date(0);
UnitSystem unit = UnitSystem.SI;
List<WeatherCondition> conditions = new ArrayList<WeatherCondition>();
/**
* Creates the weather from the input stream with XML
* received from API.
*/
public GoogleWeather(Reader xml) throws WeatherException {
try {
parse(xml);
} catch (Exception e) {
throw new WeatherException("cannot parse xml", e);
}
}
//@Override
public Location getLocation() {
return this.location;
}
//@Override
public Date getTime() {
if (this.time.after(this.date)) { //sometimes time is 0, but the date has correct value
return this.time;
} else {
return this.date;
}
}
//@Override
public UnitSystem getUnitSystem() {
return this.unit;
}
//@Override
public List<WeatherCondition> getConditions() {
return this.conditions;
}
//@Override
public boolean isEmpty() {
return this.conditions.isEmpty();
}
void parse(Reader xml)
throws SAXException, ParserConfigurationException, IOException {
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setNamespaceAware(true); //WTF??? Harmony's Expat is so...
//factory.setFeature("http://xml.org/sax/features/namespaces", false);
//factory.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
SAXParser parser = factory.newSAXParser();
//explicitly decoding from UTF-8 because Google misses encoding in XML preamble
parser.parse(new InputSource(xml), new ApiXmlHandler());
}
/**
* Sets the location.
* Used by the weather source if the location, returned from API is empty.
*/
void setLocation(Location location) {
this.location = location;
}
static enum HandlerState {
CURRENT_CONDITIONS, FIRST_FORECAST, NEXT_FORECAST;
}
class ApiXmlHandler extends DefaultHandler {
HandlerState state;
SimpleWeatherCondition condition;
SimpleTemperature temperature;
@Override
public void startElement(String uri, String localName,
String qName, Attributes attributes) throws SAXException {
String data = attributes.getValue("data");
if ("city".equals(localName)) {
GoogleWeather.this.location = new SimpleLocation(data);
} else if ("forecast_date".equals(localName)) {
try {
GoogleWeather.this.date = DATE_FORMAT.parse(data);
} catch (ParseException e) {
throw new SAXException("invalid 'forecast_date' format: " + data, e);
}
} else if ("current_date_time".equals(localName)) {
try {
GoogleWeather.this.time = TIME_FORMAT.parse(data);
} catch (ParseException e) {
throw new SAXException("invalid 'current_date_time' format: " + data, e);
}
} else if ("unit_system".equals(localName)) {
GoogleWeather.this.unit = UnitSystem.valueOf(data);
} else if ("current_conditions".equals(localName)) {
state = HandlerState.CURRENT_CONDITIONS;
addCondition();
} else if ("forecast_conditions".equals(localName)) {
switch (state) {
case CURRENT_CONDITIONS:
state = HandlerState.FIRST_FORECAST;
break;
case FIRST_FORECAST:
state = HandlerState.NEXT_FORECAST;
addCondition();
break;
default:
addCondition();
}
} else if ("condition".equals(localName)) {
switch (state) {
case FIRST_FORECAST:
//skipping update of condition, because the current conditions are already set
break;
default:
condition.setConditionText(data);
}
} else if ("temp_f".equalsIgnoreCase(localName)) {
if (UnitSystem.US.equals(GoogleWeather.this.unit)) {
try {
temperature.setCurrent(Integer.parseInt(data), UnitSystem.US);
} catch (NumberFormatException e) {
throw new SAXException("invalid 'temp_f' format: " + data, e);
}
}
} else if ("temp_c".equals(localName)) {
if (UnitSystem.SI.equals(GoogleWeather.this.unit)) {
try {
temperature.setCurrent(Integer.parseInt(data), UnitSystem.SI);
} catch (NumberFormatException e) {
throw new SAXException("invalid 'temp_c' format: " + data, e);
}
}
} else if ("humidity".equals(localName)) {
condition.setHumidityText(data);
} else if ("wind_condition".equals(localName)) {
condition.setWindText(data);
} else if ("low".equals(localName)) {
try {
temperature.setLow(Integer.parseInt(data), GoogleWeather.this.unit);
} catch (NumberFormatException e) {
throw new SAXException("invalid 'low' format: " + data, e);
}
} else if ("high".equals(localName)) {
try {
temperature.setHigh(Integer.parseInt(data), GoogleWeather.this.unit);
} catch (NumberFormatException e) {
throw new SAXException("invalid 'high' format: " + data, e);
}
}
}
//@Override
//public void endElement(String uri, String localName, String qName)
// throws SAXException {
// boolean dummy = true;
//}
void addCondition() {
condition = new SimpleWeatherCondition();
temperature = new SimpleTemperature(GoogleWeather.this.unit);
condition.setTemperature(temperature);
GoogleWeather.this.conditions.add(condition);
}
}
}