Android Open Source - Sunshine Weather Data Parser

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License

The source code is released under:
MIT License
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Java Source Code

package net.alteridem.sunshine;
/*from w ww.  j  a v a 2 s.  c  o m*/
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.util.Log;

import net.alteridem.sunshine.data.WeatherContract;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Vector;

public class WeatherDataParser {

    private static final String LOG_TAG = WeatherDataParser.class.getSimpleName();
    private Context mContext;
    private String mLocationSetting;

    public WeatherDataParser(Context context, String locationSetting) {
        this.mContext = context;
        mLocationSetting = locationSetting;
    }

    /* The date/time conversion code is going to be moved outside the asynctask later,
         * so for convenience we're breaking it out into its own method now.
         */
    private static String getReadableDateString(long time){
        // Because the API returns a unix timestamp (measured in seconds),
        // it must be converted to milliseconds in order to be converted to valid date.
        Date date = new Date(time * 1000);
        SimpleDateFormat format = new SimpleDateFormat("E, MMM d");
        return format.format(date);
    }

    private static double convertToImperial(double celsius) {
        return 1.8 * celsius + 32;
    }

    /**
     * Prepare the weather high/lows for presentation.
     */
    private static String formatHighLows(double high, double low) {
        // For presentation, assume the user doesn't care about tenths of a degree.
        long roundedHigh = Math.round(high);
        long roundedLow = Math.round(low);

        return roundedHigh + "/" + roundedLow;
    }

    /**
     * Take the String representing the complete forecast in JSON Format and
     * pull out the data we need to construct the Strings needed for the wireframes.
     *
     * Fortunately parsing is easy:  constructor takes the JSON string and converts it
     * into an Object hierarchy for us.
     */
    public String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
            throws JSONException {
        // These are the names of the JSON objects that need to be extracted.
        // Location information
        final String OWM_CITY = "city";
        final String OWM_CITY_NAME = "name";
        final String OWM_COORD = "coord";
        final String OWM_COORD_LAT = "lat";
        final String OWM_COORD_LONG = "lon";

        // Weather information.  Each day's forecast info is an element of the "list" array.
        final String OWM_LIST = "list";

        final String OWM_DATETIME = "dt";
        final String OWM_PRESSURE = "pressure";
        final String OWM_HUMIDITY = "humidity";
        final String OWM_WINDSPEED = "speed";
        final String OWM_WIND_DIRECTION = "deg";

        // All temperatures are children of the "temp" object.
        final String OWM_TEMPERATURE = "temp";
        final String OWM_MAX = "max";
        final String OWM_MIN = "min";

        final String OWM_WEATHER = "weather";
        final String OWM_DESCRIPTION = "main";
        final String OWM_WEATHER_ID = "id";

        JSONObject forecastJson = new JSONObject(forecastJsonStr);
        JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);

        JSONObject cityJson = forecastJson.getJSONObject(OWM_CITY);
        String cityName = cityJson.getString(OWM_CITY_NAME);
        JSONObject coordJSON = cityJson.getJSONObject(OWM_COORD);
        double cityLatitude = coordJSON.getDouble(OWM_COORD_LAT);
        double cityLongitude = coordJSON.getDouble(OWM_COORD_LONG);

        Log.v(LOG_TAG, cityName + ", with coord: " + cityLatitude + " " + cityLongitude);

        // Insert the location into the database.
        // The function referenced here is not yet implemented, so we've commented it out for now.
        long locationID = insertLocationInDatabase(mLocationSetting, cityName, cityLatitude, cityLongitude);

        // Get and insert the new weather information into the database
        Vector<ContentValues> cVVector = new Vector<ContentValues>(weatherArray.length());

        String[] resultStrs = new String[numDays];

        for(int i = 0; i < weatherArray.length(); i++) {
            // These are the values that will be collected.

            long dateTime;
            double pressure;
            int humidity;
            double windSpeed;
            double windDirection;

            double high;
            double low;

            String description;
            int weatherId;

            // Get the JSON object representing the day
            JSONObject dayForecast = weatherArray.getJSONObject(i);

            // The date/time is returned as a long.  We need to convert that
            // into something human-readable, since most people won't read "1400356800" as
            // "this saturday".
            dateTime = dayForecast.getLong(OWM_DATETIME);

            pressure = dayForecast.getDouble(OWM_PRESSURE);
            humidity = dayForecast.getInt(OWM_HUMIDITY);
            windSpeed = dayForecast.getDouble(OWM_WINDSPEED);
            windDirection = dayForecast.getDouble(OWM_WIND_DIRECTION);

            // Description is in a child array called "weather", which is 1 element long.
            // That element also contains a weather code.
            JSONObject weatherObject =
                    dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
            description = weatherObject.getString(OWM_DESCRIPTION);
            weatherId = weatherObject.getInt(OWM_WEATHER_ID);

            // Temperatures are in a child object called "temp".  Try not to name variables
            // "temp" when working with temperature.  It confuses everybody.
            JSONObject temperatureObject = dayForecast.getJSONObject(OWM_TEMPERATURE);
            high = temperatureObject.getDouble(OWM_MAX);
            low = temperatureObject.getDouble(OWM_MIN);

            ContentValues weatherValues = new ContentValues();

            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_LOC_KEY, locationID);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_DATETEXT,
                    WeatherContract.getDbDateString(new Date(dateTime * 1000L)));
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_HUMIDITY, humidity);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_PRESSURE, pressure);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_WIND_SPEED, windSpeed);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_DEGREES, windDirection);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_MAX_TEMP, high);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_MIN_TEMP, low);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_SHORT_DESC, description);
            weatherValues.put(WeatherContract.WeatherEntry.COLUMN_WEATHER_ID, weatherId);

            cVVector.add(weatherValues);

            String highAndLow = formatHighLows(high, low);
            String day = getReadableDateString(dateTime);
            resultStrs[i] = day + " - " + description + " - " + highAndLow;
        }
        insertWeatherInDatabase(cVVector);
        deleteOldWeatherData();
        return resultStrs;
    }

    private long insertLocationInDatabase(String locationSetting, String cityName, double cityLatitude, double cityLongitude) {
        Log.v(LOG_TAG, "inserting " + cityName + ", with coord: " + cityLatitude + ", " + cityLongitude);
        // First, check if the location with this city name exists in the db
        Cursor cursor = mContext.getContentResolver().query(
                WeatherContract.LocationEntry.CONTENT_URI,
                new String[]{WeatherContract.LocationEntry._ID},
                WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING + " = ?",
                new String[]{locationSetting},
                null);

        if (cursor.moveToFirst()) {
            Log.v(LOG_TAG, "Found it in the database!");
            int locationIdIndex = cursor.getColumnIndex(WeatherContract.LocationEntry._ID);
            return cursor.getLong(locationIdIndex);
        }

        Log.v(LOG_TAG, "Didn't find it in the database, inserting now!");
        ContentValues values = new ContentValues();
        values.put(WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING, locationSetting);
        values.put(WeatherContract.LocationEntry.COLUMN_CITY_NAME, cityName);
        values.put(WeatherContract.LocationEntry.COLUMN_COORD_LAT, cityLatitude);
        values.put(WeatherContract.LocationEntry.COLUMN_COORD_LONG, cityLongitude);

        Uri returnUri = mContext.getContentResolver().insert(WeatherContract.LocationEntry.CONTENT_URI, values);
        return ContentUris.parseId(returnUri);
    }

    private void insertWeatherInDatabase(Vector<ContentValues> cVVector) {
        if (cVVector.size() > 0) {
            ContentValues[] values = new ContentValues[cVVector.size()];
            int rows = mContext.getContentResolver().bulkInsert(
                    WeatherContract.WeatherEntry.CONTENT_URI,
                    cVVector.toArray(values)
            );
            Log.v(LOG_TAG, "inserting " + rows + " weather values into the database");
        }
    }

    private void deleteOldWeatherData() {
        // Calculate yesterday's date string
        Calendar yesterday = Calendar.getInstance();
        yesterday.add(Calendar.DATE, -1);
        String[] selectionArgs = new String[]{WeatherContract.getDbDateString(yesterday.getTime())};

        mContext.getContentResolver().delete(
                WeatherContract.WeatherEntry.CONTENT_URI,
                WeatherContract.WeatherEntry.COLUMN_DATETEXT + " <= ?",
                selectionArgs
        );
        Log.v(LOG_TAG, "deleting old weather values from the database");
    }
}
Java Source Code List
