Android Bad Practices: Use of Released SQLite Resource

The code references the Android database handler after it has already been released.

The code attempts to use the Android SQLite database handler after the it has already been closed. Any further references to the handler without re-establishing the database connection will throw an exception, and can cause the application to crash if the exception is not caught.

Example 1: The following code might be from a program that caches user values temporarily in memory, but can call flushUpdates() to commit the changes to disk. The method properly closes the database handler after writing updates to the database. However, when flushUpdates() is called again, the database object is referenced again before reinitializing it.

public class ReuseDBActivity extends Activity {
  private myDBHelper dbHelper;
  private SQLiteDatabase db;

  @Override
  public void onCreate(Bundle state) {
      ...
      db = dbHelper.getWritableDatabase();
      ...
  }
  ...

  private void flushUpdates() {
      db.insert(cached_data);     // flush cached data
      dbHelper.close();
  }
  ...
}