騰訊位置服務GPS軌跡錄製-安卓篇

時間 2021-05-15

標籤 git 架構 app 工具測試 spa code orm rem 欄目騰訊简体版

原文原文鏈接

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」spa

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code

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orm

// 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;
    }