NullPointerException on getReadableDatabase()

Question

I have this method in a class (non-activity) -

public boolean usernameChk(String usrname) {

    String usrnmQuery = \"SELECT * FROM \" + TABLE_ACCOUNTS + \"         


        

Answer 1

As your class which is not an Activity this.getReadableDatabase(); is firing NullPointerException as it is not getting context to open database.

Use context to open database. try with following :

DatabaseHandler dbz = new DatabaseHandler(Activity.this);

public Context context;

public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    // assigning context Change your constructor
    this.context = context;
}

// Open database using context object
SQLiteDatabase db = this.getReadableDatabase();