kopia lustrzana https://github.com/N0BOY/FT8CN
406 wiersze
13 KiB
Java
406 wiersze
13 KiB
Java
package com.bg7yoz.ft8cn.maidenhead;
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/**
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* 梅登海德网格的处理。包括经纬度换算、距离计算。
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* @author BGY70Z
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* @date 2023-03-20
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*/
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import android.annotation.SuppressLint;
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import android.content.Context;
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import android.location.Location;
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import android.location.LocationManager;
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import com.bg7yoz.ft8cn.GeneralVariables;
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import com.bg7yoz.ft8cn.R;
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import com.google.android.gms.maps.model.LatLng;
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import java.util.List;
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public class MaidenheadGrid {
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private static final String TAG = "MaidenheadGrid";
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private static final double EARTH_RADIUS = 6371393; // 平均半径,单位：m；不是赤道半径。赤道为6378左右
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/**
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* 计算梅登海德网格的经纬度，4字符或6字符。如果网格数据不正确，返回null。如果是四字符的，尾部加ll,取中间的位置。
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*
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* @param grid 梅登海德网格数据
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* @return LatLng 返回经纬度，如果数据不正确，返回null
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*/
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public static LatLng gridToLatLng(String grid) {
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if (grid==null) return null;
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if (grid.length()==0) return null;
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//判断是不是符合梅登海德网格的规则
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if (grid.length() != 2&&grid.length() != 4 && grid.length() != 6) {
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return null;
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}
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if (grid.equalsIgnoreCase("RR73")) return null;
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if (grid.equalsIgnoreCase("RR")) return null;
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double x=0;
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double y=0;
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double z=0;
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//纬度
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double lat=0;
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if (grid.length()==2){
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x=grid.toUpperCase().getBytes()[1]-'A'+0.5f;
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}else {
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x=grid.toUpperCase().getBytes()[1]-'A';
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}
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x*=10;
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if (grid.length()==4){
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y=grid.getBytes()[3]-'0'+0.5f;
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}else if (grid.length()==6){
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y=grid.getBytes()[3]-'0';
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}
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if (grid.length()==6){
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z=grid.toUpperCase().getBytes()[5]-'A'+0.5f;
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z=z*(1/18f);
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}
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lat=x+y+z-90;
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//经度
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x=0;
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y=0;
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z=0;
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double lng=0;
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if (grid.length()==2){
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x=grid.toUpperCase().getBytes()[0]-'A'+0.5;
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}else {
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x=grid.toUpperCase().getBytes()[0]-'A';
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}
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x*=20;
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if (grid.length()==4){
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y=grid.getBytes()[2]-'0'+0.5;
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}else if (grid.length()==6){
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y=grid.getBytes()[2]-'0';
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}
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y*=2;
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if (grid.length()==6){
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z=grid.toUpperCase().getBytes()[4]-'A'+0.5;
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z=z*(2/18f);
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}
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lng=x+y+z-180;
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if (lat>85) lat=85;//防止在地图上越界
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if (lat<-85) lat=-85;//防止在地图上越界
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return new LatLng(lat,lng);
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}
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public static LatLng[] gridToPolygon(String grid) {
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if (grid.length() != 2 && grid.length() != 4 && grid.length() != 6) {
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return null;
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}
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LatLng[] latLngs = new LatLng[4];
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//纬度1
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double x;
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double y = 0;
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double z = 0;
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double lat1;
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x = grid.toUpperCase().getBytes()[1] - 'A';
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x *= 10;
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if (grid.length() > 2) {
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y = grid.getBytes()[3] - '0';
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}
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if (grid.length() > 4) {
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z = grid.toUpperCase().getBytes()[5] - 'A';
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z = z * (1f / 18f);
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}
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lat1 = x + y + z - 90;
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if (lat1<-85.0){
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lat1=-85.0;
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}
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if (lat1>85.0){
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lat1=85.0;
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}
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//纬度2
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x = 0;
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y = 0;
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z = 0;
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double lat2;
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if (grid.length() == 2) {
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x = grid.toUpperCase().getBytes()[1] - 'A' + 1;
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} else {
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x = grid.toUpperCase().getBytes()[1] - 'A';
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}
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x *= 10;
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if (grid.length() == 4) {
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y = grid.getBytes()[3] - '0' + 1;
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} else if (grid.length() == 6) {
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y = grid.getBytes()[3] - '0';
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}
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if (grid.length() == 6) {
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z = grid.toUpperCase().getBytes()[5] - 'A' + 1;
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z = z * (1f / 18f);
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}
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lat2 = x + y + z - 90;
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if (lat2<-85.0){
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lat2=-85.0;
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}
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if (lat2>85.0){
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lat2=85.0;
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}
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//经度1
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x=0;y=0;z=0;
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double lng1;
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x=grid.toUpperCase().getBytes()[0]-'A';
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x*=20;
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if (grid.length()>2){
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y=grid.getBytes()[2]-'0';
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y*=2;
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}
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if (grid.length()>4){
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z=grid.toUpperCase().getBytes()[4]-'A';
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z=z*2/18f;
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}
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lng1=x+y+z-180;
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//经度2
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x=0;y=0;z=0;
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double lng2;
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if (grid.length()==2){
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x=grid.toUpperCase().getBytes()[0]-'A'+1;
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}else {
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x=grid.toUpperCase().getBytes()[0]-'A';
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}
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x*=20;
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if (grid.length()==4){
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y=grid.getBytes()[2]-'0'+1;
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}else if (grid.length()==6){
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y=grid.getBytes()[2]-'0';
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}
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y*=2;
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if (grid.length()==6){
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z=grid.toUpperCase().getBytes()[4]-'A'+1;
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z=z*2/18f;
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}
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lng2=x+y+z-180;
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latLngs[0] = new LatLng(lat1,lng1);
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latLngs[1] = new LatLng(lat1,lng2);
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latLngs[2] = new LatLng(lat2,lng2);
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latLngs[3] = new LatLng(lat2,lng1);
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return latLngs;
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}
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/**
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* 此函数根据纬度计算 6 字符 Maidenhead网格。
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* 经纬度采用 NMEA 格式。换句话说，西经和南纬度为负数。它们被指定为double类型
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*
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* @param location 经纬度
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* @return String 梅登海德字符
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*/
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public static String getGridSquare(LatLng location) {
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double tempNumber;//用于中间计算
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int index;//确定要显示的字符
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double _long = location.longitude;
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double _lat = location.latitude;
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StringBuilder buff = new StringBuilder();
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/*
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* 计算第一对两个字符
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*/
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_long += 180; // 从太平洋中部开始
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tempNumber = _long / 20; // 每个主要正方形都是 20 度宽
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index = (int) tempNumber; // 大写字母的索引
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buff.append(String.valueOf((char) (index + 'A'))); // 设置第一个字符
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_long = _long - (index * 20); // 第 2 步的剩余部分
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_lat += 90; //从南极开始 180 度
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tempNumber = _lat / 10; // 每个大正方形高 10 度
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index = (int) tempNumber; // 大写字母的索引
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buff.append(String.valueOf((char) (index + 'A')));//设置第二个字符
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_lat = _lat - (index * 10); // 第 2 步的剩余部分
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/*
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* 现在是第二对两数字：
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*/
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tempNumber = _long / 2; // 步骤 1 的余数除以 2
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index = (int) tempNumber; // 数字索引
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buff.append(String.valueOf((char) (index + '0')));//设置第三个字符
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_long = _long - (index * 2); //第 3 步的剩余部分
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tempNumber = _lat; // 步骤 1 的余数除以 1
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index = (int) tempNumber; // 数字索引
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buff.append(String.valueOf((char) (index + '0')));//设置第四个字符
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_lat = _lat - index; //第 3 步的剩余部分
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/*
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*现在是第三对两个小写字符：
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*/
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tempNumber = _long / 0.083333; //步骤 2 的余数除以 0.083333
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index = (int) tempNumber; // 小写字母的索引
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buff.append(String.valueOf((char) (index + 'a')));//设置第五个字符
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tempNumber = _lat / 0.0416665; // 步骤 2 的余数除以 0.0416665
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index = (int) tempNumber; // 小写字母的索引
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buff.append(String.valueOf((char) (index + 'a')));//设置第五个字符
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return buff.toString().substring(0, 4);
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}
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/**
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* 计算经纬度之间的距离
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*
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* @param latLng1 经纬度
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* @param latLng2 经纬度
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* @return 距离，公里。
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*/
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public static double getDist(LatLng latLng1, LatLng latLng2) {
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double radiansAX = Math.toRadians(latLng1.longitude); // A经弧度
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double radiansAY = Math.toRadians(latLng1.latitude); // A纬弧度
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double radiansBX = Math.toRadians(latLng2.longitude); // B经弧度
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double radiansBY = Math.toRadians(latLng2.latitude); // B纬弧度
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// 公式中“cosβ1cosβ2cos（α1-α2）+sinβ1sinβ2”的部分，得到∠AOB的cos值
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double cos = Math.cos(radiansAY) * Math.cos(radiansBY) * Math.cos(radiansAX - radiansBX)
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+ Math.sin(radiansAY) * Math.sin(radiansBY);
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double acos = Math.acos(cos); // 反余弦值
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return EARTH_RADIUS * acos / 1000; // 最终结果km
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}
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/**
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* 计算梅登海德网格之间的距离
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*
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* @param mGrid1 梅登海德网格
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* @param mGrid2 梅登海德网格2
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* @return double 两个网格之间的距离
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*/
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public static double getDist(String mGrid1, String mGrid2) {
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LatLng latLng1 = gridToLatLng(mGrid1);
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LatLng latLng2 = gridToLatLng(mGrid2);
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if (latLng1 != null && latLng2 != null) {
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return getDist(latLng1, latLng2);
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} else {
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return 0;
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}
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}
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/**
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* 计算两个网格之间的距离
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*
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* @param mGrid1 网格
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* @param mGrid2 网格
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* @return 距离
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*/
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@SuppressLint("DefaultLocale")
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public static String getDistStr(String mGrid1, String mGrid2) {
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double dist = getDist(mGrid1, mGrid2);
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if (dist == 0) {
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return "";
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} else {
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return String.format(GeneralVariables.getStringFromResource(R.string.distance), dist);
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}
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}
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public static String getDistLatLngStr(LatLng latLng1,LatLng latLng2){
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return String.format(GeneralVariables.getStringFromResource(R.string.distance), getDist(latLng1,latLng2));
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}
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/**
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* 计算两个网格之间的距离，以英文显示公里数
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*
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* @param mGrid1 网格
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* @param mGrid2 网格
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* @return 距离
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*/
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@SuppressLint("DefaultLocale")
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public static String getDistStrEN(String mGrid1, String mGrid2) {
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double dist = getDist(mGrid1, mGrid2);
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if (dist == 0) {
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return "";
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} else {
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return String.format("%.0f km", dist);
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}
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}
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/**
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* 获取本设备的经纬度
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*
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* @param context context
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* @return 经纬度
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*/
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public static LatLng getLocalLocation(Context context) {
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// 获取位置服务
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String serviceName = Context.LOCATION_SERVICE;
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// 调用getSystemService()方法来获取LocationManager对象
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LocationManager locationManager = (LocationManager) context.getSystemService(serviceName);
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// 指定LocationManager的定位方法
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//String provider = LocationManager.GPS_PROVIDER;
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// 调用getLastKnownLocation()方法获取当前的位置信息
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List<String> providers = locationManager.getProviders(true);
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Location location = null;
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for (String s : providers) {
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@SuppressLint("MissingPermission") Location l = locationManager.getLastKnownLocation(s);
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if (l == null) {
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continue;
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}
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if (location == null || l.getAccuracy() < location.getAccuracy()) {
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// Found best last known location: %s", l);
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location = l;
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}
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}
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if (location != null) {
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return new LatLng(location.getLatitude(), location.getLongitude());
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} else {
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return null;
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}
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}
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/**
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* 获取本机的梅登海德网格数据。需要定位的权限。
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*
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* @param context context
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* @return String 返回6字符的梅登海德网格。
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*/
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public static String getMyMaidenheadGrid(Context context) {
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LatLng latLng = getLocalLocation(context);
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if (latLng != null) {
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return getGridSquare(latLng);
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} else {
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//ToastMessage.show("无法定位，请确认是否有定位的权限。");
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return "";
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}
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}
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/**
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* 检查是不是梅登海德网格。如果不是返回false。
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*
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* @param s 梅登海德网格
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* @return boolean 是否是梅登海德网格。
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*/
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public static boolean checkMaidenhead(String s) {
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if (s.length() != 4 && s.length() != 6) {
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return false;
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} else {
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if (s.equals("RR73")) {
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return false;
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}
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return Character.isAlphabetic(s.charAt(0))
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&& Character.isAlphabetic(s.charAt(1))
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&& Character.isDigit(s.charAt(2))
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&& Character.isDigit(s.charAt(3));
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}
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}
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} |