Retrieve data from SQLite in RecyclerView inside fragment

I have an activity that contain custom Tablayout.

Tablayout

the Tablayot has pageViewer and link to a fragment.

Tablayot

pageViewer

I want to show data from my SQLite database in RecyclerView in fragment.

SQLite

RecyclerView

this is my codes:

DatabaseHelper.java:

package ir.shirazmetro;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHelper extends SQLiteOpenHelper
private static final String TAG = "DatabaseHelper";

public static final String DATABASE_NAME = "MetroDB.db";
public static final String TABLE_NAME = "estation";
public static final String COL_1 = "station";
public static final String COL_2 = "time";
public static final String COL_3 = "line";

public DatabaseHelper(Context context)
super(context, DATABASE_NAME, null, 1);


@Override
public void onCreate(SQLiteDatabase db)
db.execSQL("create table " + TABLE_NAME + " (COL_1,COL_2,COL_3)");


@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);


public boolean insertData(String station, String time, String line)
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_2, time);
long result = db.insert(TABLE_NAME, null, contentValues);
if (result == -1)
return false;
else
return true;



public Cursor getData()
SQLiteDatabase db = this.getWritableDatabase();
return db.rawQuery("select "+COL_2+" from " + TABLE_NAME, null);



My activity(station.java):

package ir.shirazmetro.views.activities;
import android.content.Intent;
import android.support.v4.view.ViewPager;
import android.support.design.widget.TabLayout;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
import ir.shirazmetro.DatabaseHelper;
import ir.shirazmetro.R;
import ir.shirazmetro.other.components.ButtonCell;
import ir.shirazmetro.other.components.TextViewCell;
import ir.shirazmetro.views.adapters.BasePagerAdapter;
import ir.shirazmetro.views.adapters.MoviesAdapter;

public class estation extends BaseActivity
Toolbar mToolbar;
private TabLayout tbLayout;
private ViewPager vPager;

private List<DatabaseHelper> movies = new ArrayList<DatabaseHelper>();
private RecyclerView recyclerView;
private MoviesAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_estation);

mToolbar = findViewById(R.id.tlbr1);

setSupportActionBar(mToolbar);

initView();
setupWithViewPager();
tbLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener()
@Override
public void onTabSelected(TabLayout.Tab tab)



@Override
public void onTabUnselected(TabLayout.Tab tab)



@Override
public void onTabReselected(TabLayout.Tab tab)


);

recyclerView = findViewById(R.id.myRecycler);
adapter = new MoviesAdapter(movies);

recyclerView.setLayoutManager(new LinearLayoutManager(estation.this));
recyclerView.setAdapter(adapter);
DatabaseHelper getData = (DatabaseHelper) new DatabaseHelper(this).getData();
movies.add(getData);
adapter.notifyDataSetChanged();





private void setupWithViewPager()
BasePagerAdapter basePagerAdapter = new BasePagerAdapter(this, getSupportFragmentManager());
vPager.setAdapter(basePagerAdapter);
tbLayout.setupWithViewPager(vPager);



private void initView()
vPager = findViewById(R.id.view_pager);
tbLayout = findViewById(R.id.tab_layout);
backBtn = findViewById(R.id.backBtn);

backBtn.setOnClickListener((View.OnClickListener) this);



}

and this code is my Adapter:

package ir.shira.views.adapters;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
import ir.shira.DatabaseHelper;
import ir.shira.R;
import ir.shira.models.movie;


public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MovieViewHolder>

private List<movie> movies;
private Context context;

public MoviesAdapter(List<DatabaseHelper> movies)
movies = movies;

@NonNull
@Override
public MovieViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_to_dastgheyb,parent,false);
return new MovieViewHolder(view);

@Override
public void onBindViewHolder(@NonNull MovieViewHolder holder, int position)
holder.txtTime.setText(movies.get(position).getTime());

@Override
public int getItemCount()
return movies.size();

public class MovieViewHolder extends RecyclerView.ViewHolder

public TextView txtTime;

public MovieViewHolder(View itemView)

super(itemView);
txtTime = itemView.findViewById(R.id.textView);




my app crash when I run the project, any ideas?

2 Answers
2

movies.get(position).getTime() retrieve DatabaseHelper, I think it is checked exception.

You are making mistake hear

When You creating List Obj.

private List<DatabaseHelper> movies = new ArrayList<DatabaseHelper>();


//.. List Type DatabaseHelper But You want movie ? so change this line to like this

private List<movie> movies = new ArrayList<movie>();


//movie is your model

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