前言
在地圖的使用中，尤爲在導航場景下，進行GPS軌跡錄製是十分必要而且有用的，本文會對於安卓系統下的軌跡錄製部分作一個分享。git
系統架構
對於一個GPSRecordSystem（GPS軌跡錄製系統）主要分紅3個部分：開始錄製，錄製GPS定位，結束錄製並存儲，如上圖右方所示。在實際應用中，以導航系統爲例：（1）在開始導航時（start navi）,進行錄製工做的相關配置；（2）收到安卓系統的onLocationChanged的callback進行GPSLocation的記錄；（3）結束導航（stop navi）時，中止記錄並存入文件。架構
相關代碼展現
用到的相關變量app
private LocationManager mLocationManager; // 系統locationManager private LocationListener mLocationListener; // 系統locationListener private boolean mIsRecording = false; // 是否正在錄製 private List<String> mGpsList; // 記錄gps的list private String mRecordFileName; // gps文件名稱
- 開始錄製
開始錄製通常是在整個系統工做之初，好比在導航場景下，當「開始導航」時，能夠開始進行「startRecordLocation」 的配置工具
public void startRecordLocation(Context context, String fileName) {
// 已經在錄製中不進行錄製
if (mIsRecording) {
return;
}
Toast.makeText(context, "start record location...", Toast.LENGTH_SHORT).show();
// 初始化locationManager和locationListener
mLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
mLocationListener = new MyLocationListener();
try {
// 添加listener
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mLocationListener);
} catch (SecurityException e) {
Toast.makeText(context, "start record location error!!!", Toast.LENGTH_SHORT).show();
Log.e(TAG, "startRecordLocation Exception", e);
e.printStackTrace();
}
// 記錄文件名稱，筆者這裏使用「realLocationRecord + routeID」形式進行記錄
mRecordFileName = fileName;
if (!mRecordFileName.endsWith(".gps")) {
mRecordFileName += ".gps";
}
mIsRecording = true;
}
- 錄製中記錄軌跡 記錄location通常是在獲取安卓系統onLocationChanged回調時調用「recordGPSLocation」
public void recordGPSLocation(Location location) {
if (mIsRecording && location != null) {
// 記錄location to list
mGpsList.add(locationToString(location));
}
}
locationToString工具方法測試
驅動導航工做的GPS軌跡點通常要包含如下幾個要素，經度，緯度，精度，角度，速度，時間，海拔高度，因此在此記錄下，爲後期軌跡回放作準備。ui
private String locationToString(Location location) {
StringBuilder sb = new StringBuilder();
long time = System.currentTimeMillis();
String timeStr = gpsDataFormatter.format(new Date(time));
sb.append(location.getLatitude());
sb.append(",");
sb.append(location.getLongitude());
sb.append(",");
sb.append(location.getAccuracy());
sb.append(",");
sb.append(location.getBearing());
sb.append(",");
sb.append(location.getSpeed());
sb.append(",");
sb.append(timeStr);
sb.append(",");
sb.append(df.format((double) time / 1000.0));
// sb.append(df.format(System.currentTimeMillis()/1000.0));
// sb.append(df.format(location.getTime()/1000.0));
sb.append(",");
sb.append(location.getAltitude());
sb.append("\n");
return sb.toString();
}
- 結束錄製並保存gps文件
結束錄製通常做用在整個系統的結尾，例如在導航場景下，「結束導航」時中止錄製調用「stopRecordLocation」code
public void stopRecordLocation(Context context) {
Toast.makeText(context, "stop record location, save to file...", Toast.LENGTH_SHORT).show();
// 移除listener
mLocationManager.removeUpdates(mLocationListener);
String storagePath = StorageUtil.getStoragePath(context); // 存儲的路徑
String filePath = storagePath + mRecordFileName;
saveGPS(filePath);
mIsRecording = false;
}
GPS軌跡存儲工具方法orm
private void saveGPS(String path) {
OutputStreamWriter writer = null;
try {
File outFile = new File(path);
File parent = outFile.getParentFile();
if (parent != null && !parent.exists()) {
parent.mkdirs();
}
OutputStream out = new FileOutputStream(outFile);
writer = new OutputStreamWriter(out);
for (String line : mGpsList) {
writer.write(line);
}
} catch (Exception e) {
Log.e(TAG, "saveGPS Exception", e);
e.printStackTrace();
} finally {
if (writer != null) {
try {
writer.flush();
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG, "Failed to flush output stream", e);
}
try {
writer.close();
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG, "Failed to close output stream", e);
}
}
}
}
StorageUtil的getStoragePath工具方法blog
// 存儲在跟路徑下/TencentMapSDK/navigation
private static final String NAVIGATION_PATH = "/tencentmapsdk/navigation";
// getStoragePath工具方法
public static String getStoragePath(Context context) {
if (context == null) {
return null;
}
String strFolder;
boolean hasSdcard;
try {
hasSdcard = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);
} catch (Exception e) {
Log.e(TAG, "getStoragePath Exception", e);
e.printStackTrace();
hasSdcard = false;
}
if (!hasSdcard) {
strFolder = context.getFilesDir().getPath() + NAVIGATION_PATH;
File file = new File(strFolder);
if (!file.exists()) {
file.mkdirs();
}
} else {
strFolder = Environment.getExternalStorageDirectory().getPath() + NAVIGATION_PATH;
File file = new File(strFolder);
if (!file.exists()) { // 目錄不存在，建立目錄
if (!file.mkdirs()) {
strFolder = context.getFilesDir().getPath() + NAVIGATION_PATH;
file = new File(strFolder);
if (!file.exists()) {
file.mkdirs();
}
}
} else { // 目錄存在，建立文件測試是否有權限
try {
String newFile = strFolder + "/.test";
File tmpFile = new File(newFile);
if (tmpFile.createNewFile()) {
tmpFile.delete();
}
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG, "getStoragePath Exception", e);
strFolder = context.getFilesDir().getPath() + NAVIGATION_PATH;
file = new File(strFolder);
if (!file.exists()) {
file.mkdirs();
}
}
}
}
return strFolder;
}
結果展現
最終存儲在了手機目錄下的navigation目錄rem
後續工做
後續能夠對於錄製的gps文件講解在導航場景下進行軌跡回放的分享