Android开发实现距离位置变化

来源：互联网发布：java布尔类型的程序编辑：程序博客网时间：2024/04/25 07:14

Android开发实现距离位置变化（类似滴滴打车附件的车辆)

使用技术点：
1.百度定位sdk
2.sqlite数据库(用于保存经纬度和实时更新的距离)
3.通过经纬度计算距离的算法方式
4.TimerTask 、Handler

大概思路：
1）创建项目，上传应用到百度定位sdk获得应用对应key，并配置定位服务成功。
2）将配置的定位代码块放入service中，使程序在后台不断更新经纬度
3）为应用创建数据库和相应的数据表，编写增删改查业务逻辑方法
4）编写界面，通过点击按钮控制是否开始计算距离，并引用数据库，初始化表数据，实时刷新界面
5）在service的定位代码块中计算距离，并将距离和经纬度实时的保存在数据库(注：只要经纬度发生改变，计算出来的距离就要进行保存)
6）界面的刷新显示

以下是MainActivity中的代码，通过注释可以理解思路流程.
[java] view plaincopyprint?
1. package app.ui.activity;
2. import java.util.Timer;
3. import java.util.TimerTask;
4. import android.content.Intent;
5. import android.os.Bundle;
6. import android.os.Handler;
7. import android.os.Message;
8. import android.view.View;
9. import android.view.WindowManager;
10. import android.widget.Button;
11. import android.widget.TextView;
12. import android.widget.Toast;
13. import app.db.DistanceInfoDao;
14. import app.model.DistanceInfo;
15. import app.service.LocationService;
16. import app.ui.ConfirmDialog;
17. import app.ui.MyApplication;
18. import app.ui.R;
19. import app.utils.ConstantValues;
20. import app.utils.LogUtil;
21. import app.utils.Utils;
23. public class MainActivity extends Activity {
25. private TextView mTvDistance; //控件
26. private Button mButton;
27. private TextView mLng_lat;
28. private boolean isStart = true; //是否开始计算移动距离
30. private DistanceInfoDao mDistanceInfoDao; //数据库
31. private volatile boolean isRefreshUI = true; //是否暂停刷新UI的标识
32. private static final int REFRESH_TIME = 5000; //5秒刷新一次
34. private Handler refreshHandler = new Handler(){ //刷新界面的Handler
35. public void handleMessage(Message msg) {
36. switch (msg.what) {
37. case ConstantValues.REFRESH_UI:
38. if (isRefreshUI) {
39. LogUtil.info(DistanceComputeActivity.class, "refresh ui");
40. DistanceInfo mDistanceInfo = mDistanceInfoDao.getById(MyApplication.orderDealInfoId);
41. LogUtil.info(DistanceComputeActivity.class, "界面刷新---> "+mDistanceInfo);
42. if (mDistanceInfo != null) {
43. mTvDistance.setText(String.valueOf(Utils.getValueWith2Suffix(mDistanceInfo.getDistance())));
44. mLng_lat.setText("经:"+mDistanceInfo.getLongitude()+" 纬:"+mDistanceInfo.getLatitude());
45. mTvDistance.invalidate();
46. mLng_lat.invalidate();
47. }
48. }
49. break;
50. }
51. super.handleMessage(msg);
52. }
53. };
55. //定时器，每5秒刷新一次UI
56. private Timer refreshTimer = new Timer(true);
57. private TimerTask refreshTask = new TimerTask() {
58. @Override
59. public void run() {
60. if (isRefreshUI) {
61. Message msg = refreshHandler.obtainMessage();
62. msg.what = ConstantValues.REFRESH_UI;
63. refreshHandler.sendMessage(msg);
64. }
65. }
66. };
68. @Override
69. protected void onCreate(Bundle savedInstanceState) {
70. super.onCreate(savedInstanceState);
71. getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,
72. WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); //保持屏幕常亮
73. setContentView(R.layout.activity_expensecompute);
75. startService(new Intent(this,LocationService.class)); //启动定位服务
76. Toast.makeText(this,"已启动定位服务...", 1).show();
77. init(); //初始化相应控件
78. }
80. private void init(){
81. mTvDistance = (TextView) findViewById(R.id.tv_drive_distance);
82. mDistanceInfoDao = new DistanceInfoDao(this);
83. refreshTimer.schedule(refreshTask, 0, REFRESH_TIME);
84. mButton = (Button)findViewById(R.id.btn_start_drive);
85. mLng_lat = (TextView)findViewById(R.id.longitude_Latitude);
86. }
89. @Override
90. public void onClick(View v) {
91. super.onClick(v);
92. switch (v.getId()) {
93. case R.id.btn_start_drive: //计算距离按钮
94. if(isStart)
95. {
96. mButton.setBackgroundResource(R.drawable.btn_selected);
97. mButton.setText("结束计算");
98. isStart = false;
99. DistanceInfo mDistanceInfo = new DistanceInfo();
100. mDistanceInfo.setDistance(0f); //距离初始值
101. mDistanceInfo.setLongitude(MyApplication.lng); //经度初始值
102. mDistanceInfo.setLatitude(MyApplication.lat); //纬度初始值
103. int id = mDistanceInfoDao.insertAndGet(mDistanceInfo); //将值插入数据库，并获得数据库中最大的id
104. if (id != -1) {
105. MyApplication.orderDealInfoId = id; //将id赋值到程序全局变量中(注：该id来决定是否计算移动距离)
106. Toast.makeText(this,"已开始计算...", 0).show();
107. }else{
108. Toast.makeText(this,"id is -1,无法执行距离计算代码块", 0).show();
109. }
110. }else{
111. //自定义提示框
112. ConfirmDialog dialog = new ConfirmDialog(this, R.style.dialogNoFrame){
113. @Override
114. public void setDialogContent(TextView content) {
115. content.setVisibility(View.GONE);
116. }
117. @Override
118. public void setDialogTitle(TextView title) {
119. title.setText("确认结束计算距离？");
120. }
121. @Override
122. public void startMission() {
123. mButton.setBackgroundResource(R.drawable.btn_noselect);
124. mButton.setText("开始计算");
125. isStart = true;
126. isRefreshUI = false; //停止界面刷新
127. if (refreshTimer != null) {
128. refreshTimer.cancel();
129. refreshTimer = null;
130. }
131. mDistanceInfoDao.delete(MyApplication.orderDealInfoId); //删除id对应记录
132. MyApplication.orderDealInfoId = -1; //停止定位计算
133. Toast.makeText(DistanceComputeActivity.this,"已停止计算...", 0).show();
134. }
135. };
136. dialog.show();
137. }
138. break;
139. }
140. }
141. }
以下是LocationService中的代码，即配置的百度定位sdk代码块，放在继承了service的类中 LocationService.java (方便程序在后台实时更新经纬度)
[java] view plaincopyprint?
1. package app.service;
2. import java.util.concurrent.Callable;
3. import java.util.concurrent.ExecutorService;
4. import java.util.concurrent.Executors;
5. import android.app.Service;
6. import android.content.Intent;
7. import android.os.IBinder;
8. import app.db.DistanceInfoDao;
9. import app.model.GpsLocation;
10. import app.model.DistanceInfo;
11. import app.ui.MyApplication;
12. import app.utils.BDLocation2GpsUtil;
13. import app.utils.FileUtils;
14. import app.utils.LogUtil;
15. import com.baidu.location.BDLocation;
16. import com.baidu.location.BDLocationListener;
17. import com.baidu.location.LocationClient;
18. import com.baidu.location.LocationClientOption;
19. import com.computedistance.DistanceComputeInterface;
20. import com.computedistance.impl.DistanceComputeImpl;
22. public class LocationService extends Service {
24. public static final String FILE_NAME = "log.txt"; //日志
25. LocationClient mLocClient;
26. private Object lock = new Object();
27. private volatile GpsLocation prevGpsLocation = new GpsLocation(); //定位数据
28. private volatile GpsLocation currentGpsLocation = new GpsLocation();
29. private MyLocationListenner myListener = new MyLocationListenner();
30. private volatile int discard = 1; //Volatile修饰的成员变量在每次被线程访问时，都强迫从共享内存中重读该成员变量的值。
31. private DistanceInfoDao mDistanceInfoDao;
32. private ExecutorService executor = Executors.newSingleThreadExecutor();
34. @Override
35. public IBinder onBind(Intent intent) {
36. return null;
37. }
39. @Override
40. public void onCreate() {
41. super.onCreate();
42. mDistanceInfoDao = new DistanceInfoDao(this); //初始化数据库
43. //LogUtil.info(LocationService.class, "Thread id ----------->:" + Thread.currentThread().getId());
44. mLocClient = new LocationClient(this);
45. mLocClient.registerLocationListener(myListener);
46. //定位参数设置
47. LocationClientOption option = new LocationClientOption();
48. option.setCoorType("bd09ll"); //返回的定位结果是百度经纬度，默认值gcj02
49. option.setAddrType("all"); //返回的定位结果包含地址信息
50. option.setScanSpan(5000); //设置发起定位请求的间隔时间为5000ms
51. option.disableCache(true); //禁止启用缓存定位
52. option.setProdName("app.ui.activity");
53. option.setOpenGps(true);
54. option.setPriority(LocationClientOption.GpsFirst); //设置GPS优先
55. mLocClient.setLocOption(option);
56. mLocClient.start();
57. mLocClient.requestLocation();
59. }
61. @Override
62. @Deprecated
63. public void onStart(Intent intent, int startId) {
64. super.onStart(intent, startId);
65. }
67. @Override
68. public void onDestroy() {
69. super.onDestroy();
70. if (null != mLocClient) {
71. mLocClient.stop();
72. }
73. startService(new Intent(this, LocationService.class));
74. }
76. private class Task implements Callable<String>{
77. private BDLocation location;
78. public Task(BDLocation location){
79. this.location = location;
80. }
82. /**
83. * 检测是否在原地不动
84. *
85. * @param distance
86. * @return
87. */
88. private boolean noMove(float distance){
89. if (distance < 0.01) {
90. return true;
91. }
92. return false;
93. }
95. /**
96. * 检测是否在正确的移动
97. *
98. * @param distance
99. * @return
100. */
101. private boolean checkProperMove(float distance){
102. if(distance <= 0.1 * discard){
103. return true;
104. }else{
105. return false;
106. }
107. }
109. /**
110. * 检测获取的数据是否是正常的
111. *
112. * @param location
113. * @return
114. */
115. private boolean checkProperLocation(BDLocation location){
116. if (location != null && location.getLatitude() != 0 && location.getLongitude() != 0){
117. return true;
118. }
119. return false;
120. }
122. @Override
123. public String call() throws Exception {
124. synchronized (lock) {
125. if (!checkProperLocation(location)){
126. LogUtil.info(LocationService.class, "location data is null");
127. discard++;
128. return null;
129. }
131. if (MyApplication.orderDealInfoId != -1) {
132. DistanceInfo mDistanceInfo = mDistanceInfoDao.getById(MyApplication.orderDealInfoId); //根据MainActivity中赋值的全局id查询数据库的值
133. if(mDistanceInfo != null) //不为空则说明车已经开始行使，并可以获得经纬度，计算移动距离
134. {
135. LogUtil.info(LocationService.class, "行驶中......");
136. GpsLocation tempGpsLocation = BDLocation2GpsUtil.convertWithBaiduAPI(location); //位置转换
137. if (tempGpsLocation != null) {
138. currentGpsLocation = tempGpsLocation;
139. }else{
140. discard ++;
141. }
142. //日志
143. String logMsg = "(plat:--->" + prevGpsLocation.lat + " plgt:--->" + prevGpsLocation.lng +")\n" +
144. "(clat:--->" + currentGpsLocation.lat + " clgt:--->" + currentGpsLocation.lng + ")";
145. LogUtil.info(LocationService.class, logMsg);
147. /** 计算距离 */
148. float distance = 0.0f;
149. DistanceComputeInterface distanceComputeInterface = DistanceComputeImpl.getInstance(); //计算距离类对象
150. distance = (float) distanceComputeInterface.getLongDistance(prevGpsLocation.lat,prevGpsLocation.lng,
151. currentGpsLocation.lat,currentGpsLocation.lng); //移动距离计算
152. if (!noMove(distance)) { //是否在移动
153. if (checkProperMove(distance)) { //合理的移动
154. float drivedDistance = mDistanceInfo.getDistance();
155. mDistanceInfo.setDistance(distance + drivedDistance); //拿到数据库原始距离值，加上当前值
156. mDistanceInfo.setLongitude(currentGpsLocation.lng); //经度
157. mDistanceInfo.setLatitude(currentGpsLocation.lat); //纬度
159. //日志记录
160. FileUtils.saveToSDCard(FILE_NAME,"移动距离--->:"+distance+drivedDistance+"\n"+"数据库中保存的距离"+mDistanceInfo.getDistance());
161. mDistanceInfoDao.updateDistance(mDistanceInfo);
162. discard = 1;
163. }
164. }
165. prevGpsLocation = currentGpsLocation;
166. }
167. }
168. return null;
169. }
170. }
171. }
173. /**
174. * 定位SDK监听函数
175. */
176. public class MyLocationListenner implements BDLocationListener {
177. @Override
178. public void onReceiveLocation(BDLocation location) {
179. executor.submit(new Task(location));
181. LogUtil.info(LocationService.class, "经度："+location.getLongitude());
182. LogUtil.info(LocationService.class, "纬度："+location.getLatitude());
183. //将经纬度保存于全局变量，在MainActivity中点击按钮时初始化数据库字段
184. if(MyApplication.lng <=0 && MyApplication.lat <= 0)
185. {
186. MyApplication.lng = location.getLongitude();
187. MyApplication.lat = location.getLatitude();
188. }
189. }
191. public void onReceivePoi(BDLocation poiLocation) {
192. if (poiLocation == null){
193. return ;
194. }
195. }
196. }
197. }
以下是应用中需要使用的DBOpenHelper数据库类 DBOpenHelper.java
[java] view plaincopyprint?
1. package app.db;
2. import android.content.Context;
3. import android.database.sqlite.SQLiteDatabase;
4. import android.database.sqlite.SQLiteOpenHelper;
6. public class DBOpenHelper extends SQLiteOpenHelper{
7. private static final int VERSION = 1; //数据库版本号
8. private static final String DB_NAME = "distance.db"; //数据库名
10. public DBOpenHelper(Context context){ //创建数据库
11. super(context, DB_NAME, null, VERSION);
12. }
14. @Override
15. public void onCreate(SQLiteDatabase db) { //创建数据表
16. db.execSQL("CREATE TABLE IF NOT EXISTS milestone(id INTEGER PRIMARY KEY AUTOINCREMENT, distance INTEGER,longitude DOUBLE, latitude DOUBLE )");
17. }
19. @Override
20. public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //版本号发生改变的时
21. db.execSQL("drop table milestone");
22. db.execSQL("CREATE TABLE IF NOT EXISTS milestone(id INTEGER PRIMARY KEY AUTOINCREMENT, distance INTEGER,longitude FLOAT, latitude FLOAT )");
23. }
25. }
以下是应用中需要使用的数据库业务逻辑封装类 DistanceInfoDao.java
[java] view plaincopyprint?
1. package app.db;
2. import android.content.Context;
3. import android.database.Cursor;
4. import android.database.sqlite.SQLiteDatabase;
5. import app.model.DistanceInfo;
6. import app.utils.LogUtil;
8. public class DistanceInfoDao {
9. private DBOpenHelper helper;
10. private SQLiteDatabase db;
12. public DistanceInfoDao(Context context) {
13. helper = new DBOpenHelper(context);
14. }
16. public void insert(DistanceInfo mDistanceInfo) {
17. if (mDistanceInfo == null) {
18. return;
19. }
20. db = helper.getWritableDatabase();
21. String sql = "INSERT INTO milestone(distance,longitude,latitude) VALUES('"+ mDistanceInfo.getDistance() + "','"+ mDistanceInfo.getLongitude() + "','"+ mDistanceInfo.getLatitude() + "')";
22. LogUtil.info(DistanceInfoDao.class, sql);
23. db.execSQL(sql);
24. db.close();
25. }
27. public int getMaxId() {
28. db = helper.getReadableDatabase();
29. Cursor cursor = db.rawQuery("SELECT MAX(id) as id from milestone",null);
30. if (cursor.moveToFirst()) {
31. return cursor.getInt(cursor.getColumnIndex("id"));
32. }
33. return -1;
34. }
36. /**
37. * 添加数据
38. * @param orderDealInfo
39. * @return
40. */
41. public synchronized int insertAndGet(DistanceInfo mDistanceInfo) {
42. int result = -1;
43. insert(mDistanceInfo);
44. result = getMaxId();
45. return result;
46. }
48. /**
49. * 根据id获取
50. * @param id
51. * @return
52. */
53. public DistanceInfo getById(int id) {
54. db = helper.getReadableDatabase();
55. Cursor cursor = db.rawQuery("SELECT * from milestone WHERE id = ?",new String[] { String.valueOf(id) });
56. DistanceInfo mDistanceInfo = null;
57. if (cursor.moveToFirst()) {
58. mDistanceInfo = new DistanceInfo();
59. mDistanceInfo.setId(cursor.getInt(cursor.getColumnIndex("id")));
60. mDistanceInfo.setDistance(cursor.getFloat(cursor.getColumnIndex("distance")));
61. mDistanceInfo.setLongitude(cursor.getFloat(cursor.getColumnIndex("longitude")));
62. mDistanceInfo.setLatitude(cursor.getFloat(cursor.getColumnIndex("latitude")));
63. }
64. cursor.close();
65. db.close();
66. return mDistanceInfo;
67. }
69. /**
70. * 更新距离
71. * @param orderDealInfo
72. */
73. public void updateDistance(DistanceInfo mDistanceInfo) {
74. if (mDistanceInfo == null) {
75. return;
76. }
77. db = helper.getWritableDatabase();
78. String sql = "update milestone set distance="+ mDistanceInfo.getDistance() +",longitude="+mDistanceInfo.getLongitude()+",latitude="+mDistanceInfo.getLatitude()+" where id = "+ mDistanceInfo.getId();
79. LogUtil.info(DistanceInfoDao.class, sql);
80. db.execSQL(sql);
81. db.close();
82. }
83. }
以下是需要使用到的实体类 DistanceInfo.java (set数据到对应变量，以实体类作为参数更新数据库)
[java] view plaincopyprint?
1. package app.model;
2. public class DistanceInfo {
3. private int id;
4. private float distance;
5. private double longitude;
6. private double latitude;
8. public int getId() {
9. return id;
10. }
11. public void setId(int id) {
12. this.id = id;
13. }
14. public float getDistance() {
15. return distance;
16. }
17. public void setDistance(float distance) {
18. this.distance = distance;
19. }
20. public double getLongitude() {
22. return longitude;
23. }
24. public void setLongitude(double longitude) {
26. this.longitude = longitude;
27. }
28. public double getLatitude() {
30. return latitude;
31. }
32. public void setLatitude(double latitude) {
34. this.latitude = latitude;
35. }
36. @Override
37. public String toString() {
39. return "DistanceInfo [id=" + id + ", distance=" + distance
40. + ", longitude=" + longitude + ", latitude=" + latitude + "]";
41. }
42. }
保存经纬度信息的类 GpsLocation
[java] view plaincopyprint?
1. package app.model;
2. public class GpsLocation {
3. public double lat;//纬度
4. public double lng;//经度
5. }
将从百度定位中获得的经纬度转换为精准的GPS数据 BDLocation2GpsUtil.java
[java] view plaincopyprint?
1. package app.utils;
2. import it.sauronsoftware.base64.Base64;
3. import java.io.BufferedReader;
4. import java.io.IOException;
5. import java.io.InputStreamReader;
6. import java.net.HttpURLConnection;
7. import java.net.URL;
8. import org.json.JSONObject;
9. import app.model.GpsLocation;
10. import com.baidu.location.BDLocation;
11. public class BDLocation2GpsUtil {
12. static BDLocation tempBDLocation = new BDLocation(); // 临时变量，百度位置
13. static GpsLocation tempGPSLocation = new GpsLocation(); // 临时变量，gps位置
14. public static enum Method{
15. origin, correct;
16. }
17. private static final Method method = Method.correct;
18. /**
19. * 位置转换
20. *
21. * @param lBdLocation 百度位置
22. * @return GPS位置
23. */
24. public static GpsLocation convertWithBaiduAPI(BDLocation lBdLocation) {
25. switch (method) {
26. case origin: //原点
27. GpsLocation location = new GpsLocation();
28. location.lat = lBdLocation.getLatitude();
29. location.lng = lBdLocation.getLongitude();
30. return location;
31. case correct: //纠偏
32. //同一个地址不多次转换
33. if (tempBDLocation.getLatitude() == lBdLocation.getLatitude() && tempBDLocation.getLongitude() == lBdLocation.getLongitude()) {
34. return tempGPSLocation;
35. }
36. String url = "http://api.map.baidu.com/ag/coord/convert?from=0&to=4&"
37. + "x=" + lBdLocation.getLongitude() + "&y="
38. + lBdLocation.getLatitude();
39. String result = executeHttpGet(url);
40. LogUtil.info(BDLocation2GpsUtil.class, "result:" + result);
41. if (result != null) {
42. GpsLocation gpsLocation = new GpsLocation();
43. try {
44. JSONObject jsonObj = new JSONObject(result);
45. String lngString = jsonObj.getString("x");
46. String latString = jsonObj.getString("y");
47. // 解码
48. double lng = Double.parseDouble(new String(Base64.decode(lngString)));
49. double lat = Double.parseDouble(new String(Base64.decode(latString)));
50. // 换算
51. gpsLocation.lng = 2 * lBdLocation.getLongitude() - lng;
52. gpsLocation.lat = 2 * lBdLocation.getLatitude() - lat;
53. tempGPSLocation = gpsLocation;
54. LogUtil.info(BDLocation2GpsUtil.class, "result:" + gpsLocation.lat + "||" + gpsLocation.lng);
55. } catch (Exception e) {
56. e.printStackTrace();
57. return null;
58. }
59. tempBDLocation = lBdLocation;
60. return gpsLocation;
61. }else{
62. LogUtil.info(BDLocation2GpsUtil.class, "百度API执行出错,url is:" + url);
63. return null;
64. }
65. }
66. }
67. }
需要声明相关权限，且项目中所用到的jar有：
android-support-v4.jar
commons-codec.jar
commons-lang3-3.0-beta.jar
javabase64-1.3.1.jar
locSDK_3.1.jar

项目中目前尚有部分不健全的地方，如：
1.在行驶等待时间较长后，使用TimerTask 、Handler刷新界面是偶尔会出现卡住的现象，车仍在行驶，
但是数据不动了，通过改善目前测试近7次未出现此问题。
2.较大的消耗电量,因为定位服务本身就是个消耗电量的玩意
前段时间因为项目需求，通过百度定位adk写了一个实时更新距离的程序（类似大家坐的士时，车上的里程表），遇到很多技术点，总结了一下发表出来和大家相互学习。直接要求定位具体的位置应该是不难的，只需要引入百度定位adk，并配置相关参数就可以完成，显示百度地图也类似，但是如果需要不断的实时显示移动距离，GPS定位从一个点，到第二个点，从第二个点，到第三个点，从第三个点......，移动距离是多少呢？不得不说，要实现这种需求的确存在一定的难度。
目标：使用百度定位sdk开发实时移动距离计算功能，根据经纬度的定位，计算行驶公里数并实时刷新界面显示。
大家都知道定位有三种方式：GPS 、Wifi 、基站 .
误差方面的话，使用GPS误差在10左右，Wifi则在20 - 300左右，而使用基站则误差在100 - 300左右的样子，因为在室内GPS是定位不到的，必须在室外，
而我们项目的需求正好需要使用GPS定位，所以我们这里设置GPS优先。车，不可能在室内跑吧。

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