How can I measure distance and create a bounding box based on two latitude+longitude points in Java?

I am wanting to find the distance between two different points. This I know can be accomplished with the great circle distance. http://www.meridianworlddata.com/Distance-calculation.asp

Once done, with a point and distance I would like to find the point that distance north, and that distance east in order to create a box around the point.

Here is a Java implementation of Haversine formula. I use this in a project to calculate distance in miles between lat/longs.

public static double distFrom(double lat1, double lng1, double lat2, double lng2) {
    double earthRadius = 3958.75; // miles (or 6371.0 kilometers)
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double sindLat = Math.sin(dLat / 2);
    double sindLng = Math.sin(dLng / 2);
    double a = Math.pow(sindLat, 2) + Math.pow(sindLng, 2)
            * Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2));
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    double dist = earthRadius * c;

    return dist;
    }

Or you could use SimpleLatLng. Apache 2.0 licensed and used in one production system that I know of: mine.

Short story:

I was searching for a simple geo library and couldn't find one to fit my needs. And who wants to write and test and debug these little geo tools over and over again in every application? There's got to be a better way!

So SimpleLatLng was born as a way to store latitude-longitude data, do distance calculations, and create shaped boundaries.

I know I'm two years too late to help the original poster, but my aim is to help the people like me who find this question in a search. I would love to have some people use it and contribute to the testing and vision of this little lightweight utility.

We've had some success using OpenMap to plot a lot of positional data. There's a LatLonPoint class that has some basic functionality, including distance.

For a more accurate distance (0.5mm) you can also use the Vincenty approximation:

/**
 * Calculates geodetic distance between two points specified by latitude/longitude using Vincenty inverse formula
 * for ellipsoids
 * 
 * @param lat1
 *            first point latitude in decimal degrees
 * @param lon1
 *            first point longitude in decimal degrees
 * @param lat2
 *            second point latitude in decimal degrees
 * @param lon2
 *            second point longitude in decimal degrees
 * @returns distance in meters between points with 5.10<sup>-4</sup> precision
 * @see <a href="http://www.movable-type.co.uk/scripts/latlong-vincenty.html">Originally posted here</a>
 */
public static double distVincenty(double lat1, double lon1, double lat2, double lon2) {
    double a = 6378137, b = 6356752.314245, f = 1 / 298.257223563; // WGS-84 ellipsoid params
    double L = Math.toRadians(lon2 - lon1);
    double U1 = Math.atan((1 - f) * Math.tan(Math.toRadians(lat1)));
    double U2 = Math.atan((1 - f) * Math.tan(Math.toRadians(lat2)));
    double sinU1 = Math.sin(U1), cosU1 = Math.cos(U1);
    double sinU2 = Math.sin(U2), cosU2 = Math.cos(U2);

    double sinLambda, cosLambda, sinSigma, cosSigma, sigma, sinAlpha, cosSqAlpha, cos2SigmaM;
    double lambda = L, lambdaP, iterLimit = 100;
    do {
        sinLambda = Math.sin(lambda);
        cosLambda = Math.cos(lambda);
        sinSigma = Math.sqrt((cosU2 * sinLambda) * (cosU2 * sinLambda)
                + (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda) * (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda));
        if (sinSigma == 0)
            return 0; // co-incident points
        cosSigma = sinU1 * sinU2 + cosU1 * cosU2 * cosLambda;
        sigma = Math.atan2(sinSigma, cosSigma);
        sinAlpha = cosU1 * cosU2 * sinLambda / sinSigma;
        cosSqAlpha = 1 - sinAlpha * sinAlpha;
        cos2SigmaM = cosSigma - 2 * sinU1 * sinU2 / cosSqAlpha;
        if (Double.isNaN(cos2SigmaM))
            cos2SigmaM = 0; // equatorial line: cosSqAlpha=0 (§6)
        double C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
        lambdaP = lambda;
        lambda = L + (1 - C) * f * sinAlpha
                * (sigma + C * sinSigma * (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));
    } while (Math.abs(lambda - lambdaP) > 1e-12 && --iterLimit > 0);

    if (iterLimit == 0)
        return Double.NaN; // formula failed to converge

    double uSq = cosSqAlpha * (a * a - b * b) / (b * b);
    double A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
    double B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
    double deltaSigma = B
            * sinSigma
            * (cos2SigmaM + B
                    / 4
                    * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B / 6 * cos2SigmaM
                            * (-3 + 4 * sinSigma * sinSigma) * (-3 + 4 * cos2SigmaM * cos2SigmaM)));
    double dist = b * A * (sigma - deltaSigma);

    return dist;
}

This code was freely adapted from http://www.movable-type.co.uk/scripts/latlong-vincenty.html

Corrected Haversine Distance formula....

public static double HaverSineDistance(double lat1, double lng1, double lat2, double lng2) 
{
    // mHager 08-12-2012
    // http://en.wikipedia.org/wiki/Haversine_formula
    // Implementation

    // convert to radians
    lat1 = Math.toRadians(lat1);
    lng1 = Math.toRadians(lng1);
    lat2 = Math.toRadians(lat2);
    lng2 = Math.toRadians(lng2);

    double dlon = lng2 - lng1;
    double dlat = lat2 - lat1;

    double a = Math.pow((Math.sin(dlat/2)),2) + Math.cos(lat1) * Math.cos(lat2) * Math.pow(Math.sin(dlon/2),2);

    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));

    return EARTH_RADIUS * c;
}