Android: Nullpointerexception On Getwritabledatabase()

Here is where I try to access the database: UserDataAdapter dbHelper = new UserDataAdapter(this); dbHelper.open(); dbHelper.createNetwork(network); dbHelper.close(); UserDataAdapt

Solution 1:

Make sure if your Context is properly being set or not.

private Context context;
private SQLiteDatabase database;
private DatabaseHelper dbHelper;

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

public UserDataAdapter open() throws SQLException
{
    dbHelper = new DatabaseHelper(context);
    database = dbHelper.getWritableDatabase();
    returnthis;
}

Solution 2:

FYI: I've had the NullPointerException error with a standard ContentProvider implementation. I finally solved it and the key is related to context/intent in the manifest file.

In the end I was missing this line from my inside my manifest's activity's .

<data android:mimeType="vnd.android.cursor.dir/vnd.pmp.smsmessage" />

Checkout the NotePad sample for what I am talking about. Also I prefer to use the structure here http://www.vogella.com/articles/AndroidSQLite/article.html however as his tut is designed for 3.0 had to leave out all the loader stuff for 2.2 implementation ...

After putting it in my database created and I could insert rows. I tested this simply using the onCreate for my default activity.

ContentValues values=new ContentValues();
values.put("somefieldname","somevalue");
values.put("otherfieldname","othervalue");
getContentResolver().insert(MyProvider.CONTENT_URI, values);

Solution 3:

This happens when you try to open the database from a Service or Activity constructor. Try moving the open to onCreate().