Trying to test SQLiteOpenHelper but getWritableDatabase() throws Null

Question

I'm trying to write a junit test against my apps database in Android Studio using my SQLiteOpenHelper object. Every time it hits the insert method I get a NullPointerException. I've gone back and forth between using getContext() and a mockContext I setup but no dice. I have my emulator up and running. Can someone please tell me what I'm doing wrong?

public class LocationDatabaseHelperTest extends AndroidTestCase {

    private SQLiteDatabase testDB;
    private SQLiteDatabase readDB;
    private LocationDatabaseHelper dbh;
    private RenamingDelegatingContext mockContext;
    private ContentValues cv;



    /**
     *Sets up a mock context to initialize the
     * LocationDatabaseHelper object.
     * @throws Exception
     */
    public void setUp() throws Exception {
        super.setUp();


        final String prefix = "test";
        mockContext = new RenamingDelegatingContext(getContext(),prefix);
        dbh = new LocationDatabaseHelper(mockContext);

        try {
            testDB = dbh.getWritableDatabase();
        } catch(Exception ex){
            ex.printStackTrace();
        }

        readDB = dbh.getReadableDatabase();
        cv = new ContentValues();
    }


    /**
     *Tests that asserts LocationDatabaseHelper object instantiates.
     */
    public void testLocationDatabaseHelper() {
        assertNotNull(dbh);
    }



    public void testInsert() {


        String id = "seattle";
        float heading = (float) 20.178545;
        double longitude = 122.20;
        double lat = 47.37;
        float speed = (float) 65.4587;
        long time = System.currentTimeMillis();
        LocationPackage locations = new LocationPackage(id,heading,longitude, lat,speed, time);


        cv.put(dbh.COLUMN_LOCATION_id, (String) locations.id);
        cv.put(dbh.COLUMN_LOCATION_HEADING, (float) locations.heading);
        cv.put(dbh.COLUMN_LOCATION_lat, (double) locations.latitude);
        cv.put(dbh.COLUMN_LOCATION_SPEED, (float) locations.speed);
        cv.put(dbh.COLUMN_LOCATION_long, (double) locations.longitude);
        cv.put(dbh.COLUMN_LOCATION_TIMESTAMP, (long) locations.time);


         testDB.insert(dbh.TABLE_LOCATION, null, cv);



        String selectQuery = "SELECT * FROM " + dbh.TABLE_LOCATION;
        Log.i(dbh.toString(), selectQuery);
        Cursor c = readDB.rawQuery(selectQuery, null);
        if(c!=null)
            c.moveToFirst();

        String locID = c.getString(c.getColumnIndex(dbh.COLUMN_LOCATION_id));

        //Log.i("LocationID: ", locID);
        assertEquals(locID, "userid");


        //assertTrue(insertID != -1);
    }


    public void tearDown() throws Exception {

        super.tearDown();

        //dbh.clearDatabase();
    }

}

Stroganoff

Did you find a solution about this? – Phyllode

Answer 1

You forgot to open your database. Do dbh.open(). After that don't forget to close your db.

Vivyanne

I thought that is what testDB = dbh.getWritableDatabase() is supposed to do? Adding dbh.onOpen(testDB) or dbh.onCreate(testDB) also hits Null. – Stroganoff