根据经纬度周边范围搜索

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import cn.quinn.dabei.cache.HeartBeatFactory;
import cn.quinn.dabei.model.business.DriverHeartbeatEntity;

/**
 * 
 * 
 * @date 2013年8月18日下午2:50:09<br>
 */
public class MapUtils {


	public static final int ONE_LNG = 0x1b2d7;

	public final static int ONE_LAT = 0xe31f;

	public static double[] countCoordinates(double dist) {
		double l[] = new double[2];
		l[0] = 1d / ONE_LNG * dist;
		l[1] = 1d / ONE_LAT * dist;
		return l;
	}

	/**
	 * 
	 * @param lng1
	 *            经度
	 * @param lat1
	 *            纬度
	 * @param lng2
	 * @param lat2
	 * @return<br>
	 * @date 2013年8月28日下午10:36:04<br>
	 * @author 
	 */
	public static double distanceByLngLat(double lng1, double lat1, double lng2, double lat2) {
		double radLat1 = lat1 * Math.PI / 180;
		double radLat2 = lat2 * Math.PI / 180;
		double a = radLat1 - radLat2;
		double b = lng1 * Math.PI / 180 - lng2 * Math.PI / 180;
		double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
		s = s * 6378137.0;
		s = Math.round(s * 10000) / 10000;
		return s;
	}

	public static synchronized List<DriverHeartbeatEntity> getInRangeDriver(final double fromLat, final double fromLng) {
		final List<DriverHeartbeatEntity> list = new ArrayList<DriverHeartbeatEntity>();
		final Iterator<DriverHeartbeatEntity> drivers = HeartBeatFactory.getInstance().getDriver().values().iterator();
		while (drivers.hasNext()) {
			final DriverHeartbeatEntity driver = drivers.next();
			if (driver.getStatus() == DriverHeartbeatEntity.STATUS_OFF_WORK)
				continue;
			final int distance = driver.getDistance();
			final double dou[] = MapUtils.countCoordinates(distance);
			final double lat = driver.getLatitude();
			final double lng = driver.getLongitude();
			final double bigLat = lat + dou[1];
			final double smlLat = lat - dou[1];
			final double bigLng = lng + dou[0];
			final double smlLng = lng - dou[0];
			if ((fromLat <= bigLat && smlLat <= fromLat) && (fromLng <= bigLng && fromLng >= smlLng))
				list.add(driver);
		}
		return list;
	}

	public static void main(String[] args) {
		DriverHeartbeatEntity d1 = new DriverHeartbeatEntity();
		d1.setCreateTime(System.currentTimeMillis());
		d1.setLatitude(104.068791);
		d1.setLongitude(30.62948);
		d1.setUsername("a1");
		d1.setDistance(3000);
		HeartBeatFactory.getInstance().putDriver(d1);
		List<DriverHeartbeatEntity> list = getInRangeDriver(104.068699,30.629431);
		if (list != null)
			for (DriverHeartbeatEntity d : list)
				System.out.println(d.getUsername());
	}
}