Android开发之火星坐标转换工具

代码：

import java.io.InputStream;
import java.io.ObjectInputStream;

/*
 * 把获取到的真实地址转换为火星坐标
 */
public class LocationUtils {

    public static double[] standardToChina(Double x, Double y) {

        try {
            double[] haha = new double[2];
            PointDouble pointDouble = new PointDouble(x, y);
            PointDouble s2c = ModifyOffset.getInstance(
                    ModifyOffset.class.getResourceAsStream("axisoffset.dat"))
                    .s2c(pointDouble);
            haha[0] = s2c.x;
            haha[1] = s2c.y;
            return haha;
        } catch ( Exception e ) {
            e.printStackTrace();
        }

        return null;

    }

    static class ModifyOffset {
        private static ModifyOffset modifyOffset;
        static double[] X = new double[660 * 450];
        static double[] Y = new double[660 * 450];

        private ModifyOffset(InputStream inputStream) throws Exception {
            init(inputStream);
        }

        public synchronized static ModifyOffset getInstance(InputStream is)
                throws Exception {
            if ( modifyOffset == null ) {
                modifyOffset = new ModifyOffset(is);
            }
            return modifyOffset;
        }

        public void init(InputStream inputStream) throws Exception {
            ObjectInputStream in = new ObjectInputStream(inputStream);
            try {
                int i = 0;
                while ( in.available() > 0 ) {
                    if ( (i & 1) == 1 ) {
                        Y[(i - 1) >> 1] = in.readInt() / 100000.0d;
                        ;
                    } else {
                        X[i >> 1] = in.readInt() / 100000.0d;
                        ;
                    }
                    i++;
                }
            } finally {
                if ( in != null )
                    in.close();
            }
        }

        // standard -> china
        public PointDouble s2c(PointDouble pt) {
            int cnt = 10;
            double x = pt.x, y = pt.y;
            while ( cnt-- > 0 ) {
                if ( x < 71.9989d || x > 137.8998d || y < 9.9997d || y > 54.8996d )
                    return pt;
                int ix = (int) (10.0d * (x - 72.0d));
                int iy = (int) (10.0d * (y - 10.0d));
                double dx = (x - 72.0d - 0.1d * ix) * 10.0d;
                double dy = (y - 10.0d - 0.1d * iy) * 10.0d;
                x = (x + pt.x + (1.0d - dx) * (1.0d - dy) * X[ix + 660 * iy] + dx
                        * (1.0d - dy) * X[ix + 660 * iy + 1] + dx * dy
                        * X[ix + 660 * iy + 661] + (1.0d - dx) * dy
                        * X[ix + 660 * iy + 660] - x) / 2.0d;
                y = (y + pt.y + (1.0d - dx) * (1.0d - dy) * Y[ix + 660 * iy] + dx
                        * (1.0d - dy) * Y[ix + 660 * iy + 1] + dx * dy
                        * Y[ix + 660 * iy + 661] + (1.0d - dx) * dy
                        * Y[ix + 660 * iy + 660] - y) / 2.0d;
            }
            return new PointDouble(x, y);
        }

        // china -> standard
        public PointDouble c2s(PointDouble pt) {
            int cnt = 10;
            double x = pt.x, y = pt.y;
            while ( cnt-- > 0 ) {
                if ( x < 71.9989d || x > 137.8998d || y < 9.9997d || y > 54.8996d )
                    return pt;
                int ix = (int) (10.0d * (x - 72.0d));
                int iy = (int) (10.0d * (y - 10.0d));
                double dx = (x - 72.0d - 0.1d * ix) * 10.0d;
                double dy = (y - 10.0d - 0.1d * iy) * 10.0d;
                x = (x + pt.x - (1.0d - dx) * (1.0d - dy) * X[ix + 660 * iy] - dx
                        * (1.0d - dy) * X[ix + 660 * iy + 1] - dx * dy
                        * X[ix + 660 * iy + 661] - (1.0d - dx) * dy
                        * X[ix + 660 * iy + 660] + x) / 2.0d;
                y = (y + pt.y - (1.0d - dx) * (1.0d - dy) * Y[ix + 660 * iy] - dx
                        * (1.0d - dy) * Y[ix + 660 * iy + 1] - dx * dy
                        * Y[ix + 660 * iy + 661] - (1.0d - dx) * dy
                        * Y[ix + 660 * iy + 660] + y) / 2.0d;
            }
            return new PointDouble(x, y);
        }


    }

    static class PointDouble {
        double x, y;

        PointDouble(double x, double y) {
            this.x = x;
            this.y = y;
        }

        public String toString() {
            return "x=" + x + ", y=" + y;
        }
    }

}