uk.org.todome.Util.java Source code

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Here is the source code for uk.org.todome.Util.java

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/*
 * Copyright (C) 2011  Chris Baines
 * Copyright (C) 2011  Rebecca Brannum
 * Copyright (C) 2011  Harry Cutts
 * Copyright (C) 2011  John Preston
 * Copyright (C) 2011  James Robinson
 * 
 * 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package uk.org.todome;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashSet;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.osmdroid.util.GeoPoint;

import android.location.Location;
import android.util.Log;

public class Util {

    // Server comms

    public static String getFileFromServer(String request) {
        StringBuilder builder = new StringBuilder();
        HttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(request);
        Log.i("Util.getFileFromServer", "Request used: " + request);
        try {
            HttpResponse response = client.execute(httpGet);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            if (statusCode == 200) {
                HttpEntity entity = response.getEntity();
                InputStream content = entity.getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(content));
                String line;
                while ((line = reader.readLine()) != null) {
                    builder.append(line);
                }
            } else {
                Log.e("", "Failed to download file");
            }
        } catch (Exception ex) {
            Log.e("Util.getFileFromServer", ex.getClass().toString() + " " + ex.getMessage());
        }

        return builder.toString();
    }

    // Data conversion

    public static int doubleToIntE6(double dub) {
        return (int) (dub * 1e6);
    }

    public static double E6IntToDouble(int integer) {
        return (double) (integer / 1e6);
    }

    public static GeoPoint locationToGeoPoint(Location loc) {
        return new GeoPoint(doubleToIntE6(loc.getLatitude()), doubleToIntE6(loc.getLongitude()));
    }

    public static Location geoPointToLocation(GeoPoint point) {
        Location loc = new Location("");
        loc.setLatitude(E6IntToDouble(point.getLatitudeE6()));
        loc.setLongitude(E6IntToDouble(point.getLongitudeE6()));
        return loc;
    }

    // Maths

    public static boolean isPointsWithinRange(GeoPoint point1, GeoPoint point2, double radius) {
        return (getDistanceBetween(point1, point2) <= radius);
    }

    public static double getDistanceBetween(GeoPoint point1, GeoPoint point2) {
        // Implemented from code at
        // http://www.movable-type.co.uk/scripts/latlong.html
        int R = 6371; // radius of Earth in km

        double lat2 = Math.toRadians(point2.getLatitudeE6() * 1e-6);
        double lat1 = Math.toRadians(point1.getLatitudeE6() * 1e-6);

        double dLat = lat2 - lat1;
        double dLon = Math.toRadians((point2.getLongitudeE6() - point1.getLongitudeE6()) * 1e-6);

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
                + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double d = R * c;

        return d;
    }

    public static <E> HashSet<E> intersection(HashSet<E> x, HashSet<E> y) {
        HashSet<E> t = new HashSet<E>(x);
        t.retainAll(y);
        return t;
    }
}