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How can I support sqlite data. When a user clears data from the application manager

In my Android application, I use a SQLite database to store and retrieve data.

When the user clears the data from the application manager, the data will be cleared. But my requirement is that when the user clears the data from the application manager, my data will be static, they will not be deleted.

How can I manage this database?

Please provide any solutions.

Thanks in advance.

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3 answers

, . , . , , onCreate SQLiteHelper, .

:

DBHelper

package vn.mve.db;

import java.util.List;

public interface DBHelper<T> {
    boolean insert(T val);
    boolean update(T val);
    boolean delete(T val);
    List<T> getList(int type);
    T getChild(Object val);
}

DBHandler

public class DBHandler extends SQLiteOpenHelper {
    private static final String TAG = DBHandler.class.getSimpleName();
    protected SQLiteDatabase db; 
    private final Context context;  
    private static String PACKAGE_NAME = "";
    private static int DATABASE_VERSION = 1;

    public DBHandler(Context context) {
        super(context, Def.DBNAME, null, DATABASE_VERSION);
        this.context = context; 
        PACKAGE_NAME = this.context.getPackageName();
        Def.FOLDER_DB = "/data/data/" + PACKAGE_NAME + "/databases/";
        Log.d(TAG, Def.FOLDER_DB);
        try {
            this.createDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }       
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            this.createDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        context.deleteDatabase(Def.DBNAME);
        onCreate(db);
    }

    public void createDataBase() throws IOException{
        // for first database;
        boolean dbExist = checkDataBase();
        if(!dbExist){
            try {
                copyDataBase("db/" + Def.DBNAME);
            } catch (Exception e) {
                Log.e(TAG, "createDatabse -> Copy failed!");
                throw new Error("Error copying database");
            }
        } else {
            open();
            boolean isExist = false;
            Cursor cursor = db.rawQuery("select DISTINCT tbl_name from sqlite_master where tbl_name = 'config'", null);
            if (cursor != null) {
                isExist = true;
                cursor.close();
            } else {
                isExist = false;
            }
            close();
            Log.d(TAG, isExist + "");
            if (!isExist) {
                this.context.deleteDatabase(Def.DBNAME);
                try {
                    Log.d(TAG, "createDatabase when database has existed");
                    copyDataBase(Def.DBNAME);
                } catch (Exception e) {
                    Log.e(TAG, "createDatabse -> Copy failed!");
                    throw new Error("Error copying database");
                }               
            }
        }
    }   
    /**
     * Copies your database from your local assets-folder to the just created empty database in the
     * system folder, from where it can be accessed and handled.
     * This is done by transfering bytestream.
     * */
    private void copyDataBase(String DB) {
        //Open your local db as the input stream
        InputStream myInput = null;
        //Open the empty db as the output stream
        OutputStream myOutput = null;
        try {
            myInput = context.getResources().getAssets().open(DB);

            // Path to the just created empty db
            String outFileName = Def.FOLDER_DB + Def.DBNAME; 
            myOutput = new FileOutputStream(outFileName);

            //transfer bytes from the inputfile to the outputfile
            byte[] buffer = new byte[1024];
            int length;
            while ((length = myInput.read(buffer)) > 0){
                myOutput.write(buffer, 0, length);
            }
        } catch (FileNotFoundException e) {
            Log.e(TAG, "copyDatabase -> File not found.");
            e.printStackTrace();
        } catch (IOException e) {
            Log.e(TAG, "copyDatabase");
        } finally {
              //Close the streams
            try {
                myOutput.flush();
                myOutput.close();
                myInput.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }   
    private boolean checkDataBase(){
        boolean checkDB = false;
        try{
            String myPath = Def.FOLDER_DB + Def.DBNAME;
            File dbFile = new File(myPath); 
            checkDB = dbFile.isFile();
            Log.d(TAG, "checkDatabase: " + String.valueOf(checkDB));
            try {
                File fTmp = new File(Def.FOLDER_DB);
                if (!fTmp.exists()) {
                    fTmp.mkdir();
                }
            } catch (Exception e) {
                Log.e(TAG, "checkDatabase" + e.getMessage());
            }
        }catch(SQLiteException e){}
        return checkDB;
    }
    public void open() {
        try {
            String myPath = Def.FOLDER_DB + Def.DBNAME;
            db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);          
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    @Override
    public synchronized void close() {
            if(db != null)
                db.close();
            super.close();
    }           
    public SQLiteDatabase getSqlDb() {
        return db;
    }
    public void setSqlDb(SQLiteDatabase sqlDb) {
        this.db = sqlDb;
    }    
}

:

public class MVideo extends DBHandler implements DBHelper<Video> {
    public static final String TAG = MVideo.class.getSimpleName();
    public MVideo(Context context) {
        super(context);
    }

    @Override
    public boolean insert(Video val) {
        open();
        ContentValues cValues = new ContentValues();
        cValues.put(Def.Video.ID, val.getId());
        cValues.put(Def.Video.TITLE, val.getTitle());
        cValues.put(Def.Video.THUMBNAIL, val.getThumbnail());
        cValues.put(Def.Video.DESCRIPTION, val.getDescription());
        cValues.put(Def.Video.ENGLISH, val.getEnglish());
        cValues.put(Def.Video.VIETNAMESE, val.getVietnamese());
        cValues.put(Def.Video.ISVIEW, val.getIsView());
        long result = db.insert(Def.Video.NAME, null, cValues);
        close();        
        return result > 0;
    }

    public boolean insertList(List<Video> list) {
        open();
        db.execSQL("BEGIN IMMEDIATE TRANSACTION");
        for (Video v : list) {
            db.execSQL(String.format("INSERT INTO " + Def.Video.NAME + " (\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",\"%s\") VALUES" + 
                    " (\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",\"%s\")",
                    Def.Video.ID, Def.Video.TITLE, Def.Video.THUMBNAIL, Def.Video.DESCRIPTION, 
                    Def.Video.ENGLISH, Def.Video.VIETNAMESE, Def.Video.ISVIEW,
                    v.getId(), v.getTitle(), v.getThumbnail(), v.getDescription(), v.getEnglish(), v.getVietnamese(), v.getIsView() + ""));
            Log.d(TAG, "insertList -> " + v.toString());
        }
        db.execSQL("COMMIT TRANSACTION");
        close();        
        return true;
    }

    @Override
    public boolean update(Video val) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean delete(Video val) {
        open();
        db.delete(Def.Video.NAME, Def.Video.ID + "=?", new String[]{val.getId()});
        close();
        return false;
    }

    @Override
    public List<Video> getList(int type) {
        List<Video> list = new ArrayList<Video>();
        open();
        Cursor c = db.rawQuery(Def.Video.GET_ALL, null);
        if (c.moveToFirst()) {
            while (c.moveToNext()) {
                String ID = c.getString(0);
                String title = c.getString(1);
                String thumbnail = c.getString(2);
                String description = c.getString(3);
                String english = c.getString(4);
                String vietnamese = c.getString(5);
                boolean isView = Boolean.parseBoolean(c.getString(6));
                list.add(new Video(ID, title, thumbnail, description, english, vietnamese, isView));
            }
        }
        close();
        return list;
    }

    @Override
    public Video getChild(Object val) {
        open();
        Cursor c = db.query(Def.Video.NAME, new String[]{
                Def.Video.ID, Def.Video.TITLE, Def.Video.THUMBNAIL, Def.Video.DESCRIPTION, 
                Def.Video.ENGLISH, Def.Video.VIETNAMESE, Def.Video.ISVIEW
        }, Def.Video.ID + "=?", new String[]{val.toString()}, null, null, null, null);
        if (c != null) {
            c.moveToFirst();
        }
        Video v = new Video(c.getString(0), c.getString(1), 
                c.getString(2), c.getString(3), c.getString(4), 
                c.getString(5), Boolean.parseBoolean(c.getString(6)));
        close();
        return v;
    } 
}
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