CODEWITHSUNDEEP
androiddatabasesqliteblobimage
kirbby
kirbby

Reputation: 53

picture isn't saved properly into the database (as BLOB)

I try to save a picture into the database as a BLOB, but its not stored properly in the database.

The byte[] which is passed is correct and has 4300 characters and in the database it just has 12 characters. That's what is stored in the DB: [B@43e7be68

Here is the code of my SQL_INSERT:

public boolean SQL_INSERT_PICTURE(PictureDatatype type) {
    try{
        this.db = openHelper.getWritableDatabase();
        Log.d(TAG, "Insert picture");
        System.out.println("insert picture");
        db.execSQL("DELETE FROM picture " +
                "where " + LinkPic + " = '" + type.getLink() + "'");
        db.execSQL("INSERT OR REPLACE INTO picture " +
                "( " + NamePic + ", " + LinkPic + ", " + PicturePic + ") " +
                "VALUES ('" + type.getName() + "', '" + type.getLink() +"', '" + 
                type.getPicture() +"')");

        System.out.println("size of the picture (bytearray): " + type.getPicture().length);
        System.out.println("the picture: " + type.getPicture());
        System.out.println("insert complete");
        db.close();
        return true;
    }
        catch(SQLException s){
            System.out.println("Insert failed");
            db.close();
            return false;
        }
}

my question is why isn't the correct byte[] stored in the DB or how can i do it? If u need more information or code pls tell me.

thx kirbby

Upvotes: 1

Views: 1329

Answers (2)

Lior
Lior

Reputation: 7915

Use this code to convert the image to a ByteArray that can be stored as a BLOB:

    private byte[] getBitmapAsByteArray(Bitmap bitmap) {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        // Middle value is quality, but PNG is lossless, so it's ignored.
        bitmap.compress(CompressFormat.PNG, 0, outputStream);
        return outputStream.toByteArray();
    }

OR

    private byte[] getBitmapAsByteArray(Bitmap bitmap) {
        final int width = bitmap.getWidth();
        final int height = bitmap.getHeight();
        ByteBuffer byteBuffer = ByteBuffer.allocate(width * height * 4);

        bitmap.copyPixelsToBuffer(byteBuffer);
        return byteBuffer.array();
    }

First option should always work. Second option assumes 32bits-per-pixel (ARGB_8888 format) thus 4 bytes. if you're bitmap is of another format (e.g 565), it needs some modifications.

When you read the image data from the database, do it like this:

   public Bitmap loadIcon(long iconId) {
       // Prepare the cursor to read from database....
       byte[] bitmapData = cursor.getBlob(cursor.getColumnIndex(Columns.Icons.DATA));

       return BitmapFactory.decodeByteArray(bitmapData, 0, bitmapData.length);
   }

Make sure that the the database is defined as BLOB when you execute your "create table" SQL statement.

Upvotes: 1

Martijn
Martijn

Reputation: 13632

Ouch, that looks like you're trying to pass a byte[] array into a string.

Assembling your SQL strings in this way is a very bad idea, for multiple reasons (security and performance).

See these two questions for prepared statements, and how to bind values to the statement without having to concatenate your SQL:

insert a picture into database(sqlite) with java code. what should i do?

Java Exception Error - Sqlite preparedStatement.setBlob

Upvotes: 0

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