My developer app problem with opening database on Android 9

问题

Can you help my?

I have created and published the app on Google play store that contains a database, I have tested it on different android phones. My app works perfect on android version (Android 10,8,5 etc...) except on Android 9, do you know how can I fix that problem? I find that problem on Huawei Smart Z, Honor P20, Samsung Y6,Xiaomi Mi. Play store console says that my app can run on that models. I am beginner in app development.

This happening on mine Huawei Smart: when I install the app it opens and crashes when I want to enter in database, and when I want to enter in app again it crashes and on logcat:

E/Path 1: data/data/com.gema/databases/ 
E/SQLiteLog: (14) cannot open file at line 36906 of [c255889bd9]
E/SQLiteLog: (14) os_unix.c:36906: (2) open(//data/data/com.gematranslate/databases/gema_recnik.db) - 
E/SQLiteDatabase: Failed to open database 'data/data/com.gematranslate/databases/gema_recnik.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (Sqlite code 14 SQLITE_CANTOPEN): Could not open database, (OS error - 2:No such file or directory)

In android manifest I put:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

This is my code for check db:

public boolean checkDataBase() {
    SQLiteDatabase checkDB = null;
    try {
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READONLY);
        myContext.getDatabasePath(DB_NAME).getPath();
        checkDB.disableWriteAheadLogging();
    } catch (SQLException e)
    {
        //
    }
    if (checkDB!= null){
        checkDB.close();
    }
    return checkDB != null? true : false;

This is my code for opening db:

public void openDataBase() {
    String myPath = DB_PATH + DB_NAME;
    myContext.getDatabasePath(DB_NAME).getPath();
    db = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.OPEN_READWRITE);
    db.disableWriteAheadLogging();

If anyone can help me, thanks a lot.

回答1:

This is a solution that is supported on all versions of Android

public class DataBase extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "database.db";
private static String DATABASE_PATH = "";
private static String LAST_DATABASE_PATH = "";
private SQLiteDatabase mDataBase;
private final Context ctx;

public DataBase2(@Nullable Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    DATABASE_PATH = context.getDatabasePath(DATABASE_NAME).getPath();
    this.ctx = context;

    if (!checkIfDBExists()) {
        createDataBase();
    }

    File dbFile = new File(Environment.getDataDirectory().getPath()+"/data/"+ BuildConfig.APPLICATION_ID +"/databases");
    if (dbFile.isDirectory()) {
        String[] child = dbFile.list();
        assert child != null;
        for (int i = 0; i < child.length; i++) {
            if (!(child[i].equals("database.db") || child[i].equals(DATABASE_NAME))) {
                new File(dbFile, child[i]).delete();
            }
        }
    }
}

public void createDataBase() {
    this.getReadableDatabase();
    this.close();
    try {
        copyDataBase();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    try {
        File DbFile = ctx.getDatabasePath(DATABASE_NAME);
        if (DbFile.exists()) {
            copyDataBase();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private boolean checkIfDBExists() {
    File dbFile = new File(DATABASE_PATH);
    return dbFile.exists();
}



public void openDataBase() {
    close();
    mDataBase = SQLiteDatabase.openDatabase(DATABASE_PATH, null, CREATE_IF_NECESSARY);
}

private void copyDataBase() throws IOException {
    InputStream mInput = ctx.getAssets().open("database.db");
    String outfileName = DATABASE_PATH;
    OutputStream mOutput = new FileOutputStream(outfileName);
    byte[] buffer = new byte[1024];
    int mLength;
    while ((mLength = mInput.read(buffer)) > 0) {
        mOutput.write(buffer, 0, mLength);
    }
    mOutput.flush();
    mInput.close();
    mOutput.close();
}

@Override
public void onCreate(SQLiteDatabase db) {
}


@Override
public synchronized void close() {
    if (mDataBase != null)
        mDataBase.close();

    SQLiteDatabase.releaseMemory();
    super.close();
}

}

来源：https://stackoverflow.com/questions/62106093/my-developer-app-problem-with-opening-database-on-android-9