SQLiteOpenHelper类中的呼叫活动

Question

In my project, I need to add an image to sqlite database. I add data to the data base just after create the database in onCreate method. To get the image as the bitmap in android, need to use an Activity. Here is my code.

public class MySqlHelper extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 15;
    private static final String DATABASE_NAME = "BirdDB";

    private static final String TABLE_BIRDS = "birds";
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_SINHALA_NAME = "sinhala_name";
    private static final String KEY_SCIENTIFIC_NAME = "scientific_name";
    private static final String KEY_DESCRIPTION = "description";
    private static final String KEY_IMAGE = "image";

    private static final String[] COLUMNS = {KEY_ID,KEY_NAME,KEY_SINHALA_NAME,KEY_SCIENTIFIC_NAME,KEY_DESCRIPTION,KEY_IMAGE};

    public MySqlHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String CREATE_TABLE = "CREATE TABLE "+TABLE_BIRDS+" ( " +
                ""+KEY_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, " +
                ""+KEY_NAME+" TEXT, "+
                ""+KEY_SINHALA_NAME+" TEXT, "+
                ""+KEY_SCIENTIFIC_NAME+" TEXT, "+
                ""+KEY_DESCRIPTION+" TEXT, "+
                ""+KEY_IMAGE+" BLOB )";

        db.execSQL(CREATE_TABLE);

        String name1 = "Sri Lanka Junglefowl";
        String name2 = "Indian Prefowl";

        String sinhalaName1 = "j,s l=l=,d";
        String sinhalaName2 = "fudKrd";

        String sceintficName1 = "Gallus lafayttii";
        String sceintficName2 = "Pavo cristatus";

        String des1 = "Male like a domestic rooster. Female:bare faced,spotted and streaked below,heavily barred on wing. Endemic.";
        String des2 = "Crest of bare-shafted feathers. Male has distinctive train.";

        BirdData bird1 = new BirdData(name1,sinhalaName1,sceintficName1,des1,imageHandler.getImage1());
        BirdData bird2 = new BirdData(name2,sinhalaName2,sceintficName2,des2,imageHandler.getImage2());

        db.insert(TABLE_BIRDS, null, addBirdData(bird1));
        db.insert(TABLE_BIRDS, null, addBirdData(bird2));
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS birds");
        this.onCreate(db);
    }


    public ContentValues addBirdData(BirdData bird){

        ContentValues values = new ContentValues();
        values.put(KEY_NAME, bird.getName());
        values.put(KEY_SINHALA_NAME, bird.getSinhalaName());
        values.put(KEY_SCIENTIFIC_NAME, bird.getScientificName());
        values.put(KEY_DESCRIPTION, bird.getDescription());
        values.put(KEY_IMAGE, bird.getImage());
        return values;
    }

    class ImageHandler extends Activity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            // TODO Auto-generated method stub
            super.onCreate(savedInstanceState);
        }

        public byte[] getImage1(){
            Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable._1);
            ByteArrayOutputStream byteArrayOutputStream1 = new ByteArrayOutputStream();
            bitmap1.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream1);
            byte[] imageByte1 = byteArrayOutputStream1.toByteArray();
            return imageByte1;
        }

        public byte[] getImage2(){
            Bitmap bitmap2 = BitmapFactory.decodeResource(getResources(), R.drawable._2);
            ByteArrayOutputStream byteArrayOutputStream1 = new ByteArrayOutputStream();
            bitmap2.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream1);
            byte[] imageByte2 = byteArrayOutputStream1.toByteArray();
            return imageByte2;
        }
    }

}

In here, I used Activity class as an inner class of SQLiteOpenHelper class. How can I call that activity in SQLiteOpenHelper class?

Answer 1

You do not need an activity to access resources.

getResources() is implemented by the Context class , which is a base class of Activity . So you just need some Context object.

As it happens, your MySqlHelper constructor already has such an object; just save it.

Answer 2

you can call getResources() on the context that you passed vie constructor ...

Full working code :

public class MySqlHelper extends SQLiteOpenHelper {

    private Context context;

    private static final int DATABASE_VERSION = 15;
    private static final String DATABASE_NAME = "BirdDB";

    private static final String TABLE_BIRDS = "birds";
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_SINHALA_NAME = "sinhala_name";
    private static final String KEY_SCIENTIFIC_NAME = "scientific_name";
    private static final String KEY_DESCRIPTION = "description";
    private static final String KEY_IMAGE = "image";

    private static final String[] COLUMNS = {KEY_ID,KEY_NAME,KEY_SINHALA_NAME,KEY_SCIENTIFIC_NAME,KEY_DESCRIPTION,KEY_IMAGE};

    public MySqlHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        // TODO Auto-generated constructor stub
        this.context = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String CREATE_TABLE = "CREATE TABLE "+TABLE_BIRDS+" ( " +
                ""+KEY_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, " +
                ""+KEY_NAME+" TEXT, "+
                ""+KEY_SINHALA_NAME+" TEXT, "+
                ""+KEY_SCIENTIFIC_NAME+" TEXT, "+
                ""+KEY_DESCRIPTION+" TEXT, "+
                ""+KEY_IMAGE+" BLOB )";

        db.execSQL(CREATE_TABLE);

        String name1 = "Sri Lanka Junglefowl";
        String name2 = "Indian Prefowl";

        String sinhalaName1 = "j,s l=l=,d";
        String sinhalaName2 = "fudKrd";

        String sceintficName1 = "Gallus lafayttii";
        String sceintficName2 = "Pavo cristatus";

        String des1 = "Male like a domestic rooster. Female:bare faced,spotted and streaked below,heavily barred on wing. Endemic.";
        String des2 = "Crest of bare-shafted feathers. Male has distinctive train.";

        ImageHanlder imageHandler = new ImageHandler(context);

        BirdData bird1 = new BirdData(name1,sinhalaName1,sceintficName1,des1,imageHandler.getImage1());
        BirdData bird2 = new BirdData(name2,sinhalaName2,sceintficName2,des2,imageHandler.getImage2());

        db.insert(TABLE_BIRDS, null, addBirdData(bird1));
        db.insert(TABLE_BIRDS, null, addBirdData(bird2));
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS birds");
        this.onCreate(db);
    }


    public ContentValues addBirdData(BirdData bird){

        ContentValues values = new ContentValues();
        values.put(KEY_NAME, bird.getName());
        values.put(KEY_SINHALA_NAME, bird.getSinhalaName());
        values.put(KEY_SCIENTIFIC_NAME, bird.getScientificName());
        values.put(KEY_DESCRIPTION, bird.getDescription());
        values.put(KEY_IMAGE, bird.getImage());
        return values;
    }

    class ImageHandler  {

        private Context context;

        ImageHandler(Context context){
             this.context = context;
        }

        public byte[] getImage1(){
            Bitmap bitmap1 = BitmapFactory.decodeResource(context.getResources(), R.drawable._1);
            ByteArrayOutputStream byteArrayOutputStream1 = new ByteArrayOutputStream();
            bitmap1.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream1);
            byte[] imageByte1 = byteArrayOutputStream1.toByteArray();
            return imageByte1;
        }

        public byte[] getImage2(){
            Bitmap bitmap2 = BitmapFactory.decodeResource(context.getResources(), R.drawable._2);
            ByteArrayOutputStream byteArrayOutputStream1 = new ByteArrayOutputStream();
            bitmap2.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream1);
            byte[] imageByte2 = byteArrayOutputStream1.toByteArray();
            return imageByte2;
        }
    }

}