I am trying to create local image database using SQLite. The app works well in the AVD, but when I try to run in my Samsung S6(Android 7.0, API 24). After several attempts of failures in running the app I have restore my device. Then app worked once or twice then it started showing the same errors as given below.
06-12 19:34:10.292 17670-22492/com.example.eberhardt.test16 E/CursorWindow: Failed to read row 0, column 1 from a CursorWindow which has 0 rows, 2 columns.
06-12 19:34:10.343 17670-22492/com.example.eberhardt.test16 E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #3
Process: com.example.eberhardt.test16, PID: 17670
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:318)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:762)
Caused by: java.lang.IllegalStateException: Couldn't read row 0, col 1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
at android.database.CursorWindow.nativeGetBlob(Native Method)
at android.database.CursorWindow.getBlob(CursorWindow.java:416)
at android.database.AbstractWindowedCursor.getBlob(AbstractWindowedCursor.java:45)
at com.example.eberhardt.test16.MainActivity$featureDetection.doInBackground(MainActivity.java:343)
at com.example.eberhardt.test16.MainActivity$featureDetection.doInBackground(MainActivity.java:314)
at android.os.AsyncTask$2.call(AsyncTask.java:304)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:762)
Codes for creating the image database is
package com.example.eberhardt.test16;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import static android.provider.BaseColumns._ID;
public class imageDatabase extends SQLiteOpenHelper {
private static final String TAG = imageDatabase.class.getSimpleName();
private static final String DATABASE_NAME = "features.db";
private static final int DATABASE_VERSION = 1;
ContentResolver mContentResolver;
public final static String COLUMN_NAME = "imagename";
public final static String TABLE_NAME = "imagetable";
public imageDatabase(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
final String SQT_CREATE_IMAGE_TABLE = "CREATE TABLE " + TABLE_NAME + "(" + _ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_NAME + " BLOB" + ");";
db.execSQL(SQT_CREATE_IMAGE_TABLE);
Log.e(TAG, "Database creates successfully");
}
public void addToDb(byte[] image) throws SQLException {
ContentValues cv = new ContentValues();
cv.put(COLUMN_NAME, image);
SQLiteDatabase db = this.getWritableDatabase();
db.insert(TABLE_NAME, null, cv);
db.close();
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL(" DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
}
To store the Images
switch (requestCode){
case OPEN_GALLERY:
if(resultCode == RESULT_OK && data != null){
Uri uri = data.getData();
try {
imageBitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
} catch (IOException e) {
e.printStackTrace();
}
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream);
byte[] uploadData = outputStream.toByteArray();
imageDatabase dataBase = new imageDatabase(this);
dataBase.addToDb(uploadData);
}
break;
}
To read the images
protected Void doInBackground(Void... voids) {
imageDatabase imageDatabase = new imageDatabase(MainActivity.this);
SQLiteDatabase mDatabase = imageDatabase.getReadableDatabase();
Cursor cursor = mDatabase.rawQuery("Select * FROM imagetable", null);
cursor.moveToFirst();
Log.e("Number of rows", String.valueOf(cursor.getCount()));
for(int i = 1; i <= cursor.getCount(); i++) {
foundImage = false;
byte[] imageReceive = cursor.getBlob(1);
imageRDBitmap = BitmapFactory.decodeByteArray(imageReceive, 0, imageReceive.length);
Mat imageConverted = new Mat(imageRDBitmap.getHeight(), imageRDBitmap.getWidth(), CvType.CV_8UC4);
Utils.bitmapToMat(imageRDBitmap, imageConverted);
initializeFeatures(imageConverted);
int matchedPoints = recognizeFeature(ImageFrame);
//Log.e("Checking for matched", String.valueOf(matchedPoints));
if (matchedPoints > 20){
columnID = cursor.getInt(0);
foundImage = true;
break;
}else{
cursor.moveToNext();
}
}
if(cursor != null && !cursor.isClosed()){
cursor.close();
Log.e("RECEIVED FROM DATABASE", "is empty");
}
return null;
}
The above piece of code is to store and retrieve the images. Also in the Android manifest, I have given permission to READ and WRITE. Kindly help to find the solution for this problem.
Thank you.
