SQLiteAssetHelper扩展返回null

Question

I'm getting a NullPointerException from my DatabaseHandler.

Here is my DatabaseHandler:

public class DatabaseHandler extends SQLiteAssetHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "carsGrid",
            TABLE_CARS = "cars ",
            KEY_ID = "id",
            KEY_POSTCODE = "postcode",
            KEY_ADDRESS = "address",
            KEY_IMAGE = "image";


        public DatabaseHandler(Context context) {
            //super(context, DATABASE_NAME, null, DATABASE_VERSION);
            super(context, DATABASE_NAME, context.getExternalFilesDir(null).getAbsolutePath(), null, DATABASE_VERSION);
         }
}

MyActivity.java:

Line which is reporting error:

  // Initiate Database
            DatabaseHandler db = new DatabaseHandler(this); // "this" refer to the context

I have a feeling it's the context causing issues, but I'm not sure what the context should be. I have just changed from SQLiteOpenHelper

Previous line with error:

public DatabaseHandler(Context context) {
    //super(context, DATABASE_NAME, null, DATABASE_VERSION);
    super(context, DATABASE_NAME, context.getExternalFilesDir(null).getAbsolutePath(), null, DATABASE_VERSION);
 }

Answer 1

Try this way in your Activity

 DatabaseHandler db = new DatabaseHandler(getApplicationContext()); 

or

 DatabaseHandler db = new DatabaseHandler(YourActivity.this);