以正确的方式使用sqlite进行recyclelerview

Question

目前我正在研究recyclerview和sqlite如何从sqlite获取数据，然后将其显示给recyclerview。我让它工作但我不相信它是正确的方式。这是我的代码。

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private Toolbar mToolBar;
private NavigationView mDrawer;
private ActionBarDrawerToggle mdrawerToggle;
private DrawerLayout mDrawerLayout;

private Button alarmButton;
private AlarmManager alarmManager;
private PendingIntent sender;

private RecyclerView listReminder;
private RemindersAdapter adapter;

List<ListInfo> data;
ListInfo infoData;

Button addReminderBtn;

MyDBHandler dbHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
    requestWindowFeature(Window.FEATURE_PROGRESS);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    initDrawer();
    initView();


}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);

    mdrawerToggle.onConfigurationChanged(newConfig);
}

public void initDrawer(){
    mToolBar = (Toolbar) findViewById(R.id.app_bar);
    mDrawer = (NavigationView) findViewById(R.id.main_drawer);
    setSupportActionBar(mToolBar);
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mdrawerToggle = new ActionBarDrawerToggle(
            this,
            mDrawerLayout,
            mToolBar,
            R.string.drawer_open,
            R.string.drawer_close);
    mDrawerLayout.setDrawerListener(mdrawerToggle);
    // indicator based on whether the drawerlayout is in open or closed
    mdrawerToggle.syncState();
}


public void initView(){
    listReminder = (RecyclerView) findViewById(R.id.listData);

    dbHandler = new MyDBHandler(this);

    adapter = new RemindersAdapter(this, dbHandler.getAllData_a());
    listReminder.setAdapter(adapter);
    listReminder.setLayoutManager(new LinearLayoutManager(this));

    addReminderBtn = (Button) findViewById(R.id.addBtn);

    addReminderBtn.setOnClickListener(this);

}


@Override
public void onClick(View v) {

    switch (v.getId()){
        case R.id.addBtn:
            Intent addReminder = new Intent(this, AddReminderActivity.class);
            startActivity(addReminder);
            break;
    }
}

}

MyDBHandler.java

public class MyDBHandler extends SQLiteOpenHelper{

  private static final int DATABASE_VERSION = 6;
  private static final String DATABASE_NAME = "paroah.db";
  public static final String TABLE_REMINDER = "reminders";
  public static final  String COLUMN_ID = "_id";
  public static final  String COLUMN_TITLE_REMINDER = "title";
  public static final  String COLUMN_DESC_REMINDER = "desc";
  public static final  String COLUMN_DATE_REMINDER = "date_created";

public MyDBHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}


@Override
public void onCreate(SQLiteDatabase db) {
    String query = " CREATE TABLE "
            +TABLE_REMINDER+ "(" +
            COLUMN_ID +" INTEGER PRIMARY KEY AUTOINCREMENT,"+
            COLUMN_TITLE_REMINDER + " TEXT ,"+
            COLUMN_DESC_REMINDER + " TEXT ,"+
            COLUMN_DATE_REMINDER + " TEXT "+
            ");";

    db.execSQL(query);
}

@Override
 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// db.execSQL("DROP TABLE IF EXIST " + TABLE_REMINDER); // onCreate(db);
    Log.d("aoi", "Upgrading database from version " + oldVersion + " to "
            + newVersion + ", which will destroy all old data");
    try {
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_REMINDER);
        onCreate(db);

    } catch (SQLException e) {
        Log.d("aoi",  "getting exception "
                + e.getLocalizedMessage().toString());
    }
}

public void addReminder(ListInfo reminder ){
    ContentValues values = new ContentValues();
    values.put(COLUMN_TITLE_REMINDER, reminder.getTitle());
    values.put(COLUMN_DESC_REMINDER, reminder.getDesc());
    values.put(COLUMN_DATE_REMINDER, reminder.getDate());

    SQLiteDatabase db = getWritableDatabase();

    db.insert(TABLE_REMINDER, null, values);
    db.close();
}

public void printDatabase(){
    SQLiteDatabase db = getWritableDatabase();


}

public List<ListInfo> getAllData_a(){
    SQLiteDatabase db = getWritableDatabase();

    String query = "SELECT * FROM "+TABLE_REMINDER;

    Cursor cursor=db.rawQuery(query, null);
    List<ListInfo> data=new ArrayList<>();

    while (cursor.moveToNext()){
        int _id=cursor.getInt(cursor.getColumnIndex(COLUMN_ID));
        String title = cursor.getString(cursor.getColumnIndex(COLUMN_TITLE_REMINDER));
        String desc  = cursor.getString(cursor.getColumnIndex(COLUMN_DESC_REMINDER));
        String date  = cursor.getString(cursor.getColumnIndex(COLUMN_DATE_REMINDER));

        ListInfo current = new ListInfo();
        current.set_id(_id);
        current.title = title;
        current.desc = desc;
        current.date = date;
        data.add(current);
    }
    return data;

}
}

RemindersAdapter.java

public class RemindersAdapter extends   RecyclerView.Adapter<RemindersAdapter.ItemViewHolder> {
private final LayoutInflater inflater;
List<ListInfo> data = Collections.emptyList();

public RemindersAdapter(Context context, List<ListInfo> data){
    inflater = LayoutInflater.from(context);
    this.data = data;
}

@Override
public ItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.reminder_item, parent, false);

    ItemViewHolder holder = new ItemViewHolder(view);

    return holder;
}

@Override
public void onBindViewHolder(ItemViewHolder holder, int position) {
    ListInfo current =  data.get(position);
    holder.title.setText(current.title);
}

@Override
public int getItemCount() {
    return data.size();
}

class ItemViewHolder extends RecyclerView.ViewHolder{
    TextView title;
    public ItemViewHolder(View itemView) {
        super(itemView);
        title = (TextView) itemView.findViewById(R.id.reminderTitle);

    }
}

}

有没有其他方法可以使这段代码干净？我需要的是概念和示例，如果你有，或者我需要学习如何使它干净。 TIA !!