I want to ask that how could we populate the recyclerview from SQLite database in my android app. Actually, the data is coming from a remote server through json and my task is to populate recyclerview from making API calls when Internet is available and if it is not available then I have to save that remote server response into local SQLite database so I could fetch the saved result and populate the list in absence of Internet too
public class SQLiteHandler extends SQLiteOpenHelper {
private static final String TAG = SQLiteHandler.class.getSimpleName();
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "image_api";
// Login table name
private static final String TABLE_LIST = "images";
// Login Table Columns names
public static final String KEY_ID = "id";
public static final String KEY_TITLE = "title";
public static final String KEY_ALBUMID = "albumid";
public static final String KEY_THUMBNAILURL = "thumbnailurl";
public static final String KEY_IMAGE = "image";
SQLiteHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LIST + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_TITLE + " TEXT,"
+ KEY_ALBUMID + " TEXT UNIQUE," + KEY_THUMBNAILURL + " TEXT,"
+ KEY_IMAGE + " TEXT" + ")";
db.execSQL(CREATE_LOGIN_TABLE);
Log.d(TAG, "Database tables created");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LIST);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
void addUser(String Id, String title, String albumid, String thumbnailurl, String image) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, Id); // Name
values.put(KEY_TITLE, title); // Email
values.put(KEY_ALBUMID, albumid); // Email
values.put(KEY_THUMBNAILURL, thumbnailurl);
values.put(KEY_IMAGE, image);// Created At
// Inserting Row
long id = db.insert(TABLE_LIST, null, values);
db.close(); // Closing database connection
Log.d(TAG, "New user inserted into sqlite: " + id);
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails() {
HashMap<String, String> user = new HashMap<String, String>();
String selectQuery = "SELECT * FROM " + TABLE_LIST;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if (cursor.getCount() > 0) {
user.put("Id", cursor.getString(1));
user.put("title", cursor.getString(2));
user.put("albumid", cursor.getString(3));
user.put("thumbnailurl", cursor.getString(4));
user.put("image", cursor.getString(5));
}
cursor.close();
db.close();
// return user
Log.d(TAG, "Fetching user from Sqlite: " + user.toString());
return user;
}
long getProfilesCount() {
SQLiteDatabase db = this.getReadableDatabase();
long count = DatabaseUtils.queryNumEntries(db, TABLE_LIST);
db.close();
return count;
}
public Cursor getAllPersons() {
SQLiteDatabase db = this.getReadableDatabase();
return db.rawQuery( "SELECT * FROM " + TABLE_LIST, null );
}
}
This is my mainActivity
public class MainActivity extends AppCompatActivity {
private List<Movie> movieList;
private RecyclerView.Adapter adapter;
private SQLiteHandler db;
long profile_counts;
//private ArrayList noList;
@Override
protected void onDestroy() {
super.onDestroy();
if (db != null)
db.close();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView mList = findViewById(R.id.main_list);
db = new SQLiteHandler(getApplicationContext());
profile_counts = db.getProfilesCount();
movieList = new ArrayList<>();
adapter = new MovieAdapter(getApplicationContext(), movieList);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(mList.getContext(), linearLayoutManager.getOrientation());
mList.setHasFixedSize(true);
mList.setLayoutManager(linearLayoutManager);
mList.addItemDecoration(dividerItemDecoration);
mList.setAdapter(adapter);
if (isNetworkAvailable()) {
getData();
}
else
{
Toast.makeText(MainActivity.this,"No Internet",Toast.LENGTH_LONG).show();
}
}
private void getData() {
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setMax(100);
progressDialog.setMessage("Its loading....");
progressDialog.setTitle("Imageview Example");
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.show();
String url = "http://jsonplaceholder.typicode.com/photos";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
for (int i = 0; i < response.length(); i++) {
try {
JSONObject jsonObject = response.getJSONObject(i);
Movie movie = new Movie();
movie.setTitle(jsonObject.getString("title"));
movie.setId(jsonObject.getInt("id"));
movie.setImage(jsonObject.getString("url"));
movie.setAlbumid(jsonObject.getString("albumId"));
movie.setThumbnailurl(jsonObject.getString("thumbnailUrl"));
movieList.add(movie);
String Title = jsonObject.getString("title");
String Id = jsonObject.getString("id");
String Image = jsonObject.getString("url");
String Album = jsonObject.getString("albumId");
String Thumbnail = jsonObject.getString("thumbnailUrl");
Log.e("List Loaded", "imagesList");
Log.i("Title", Title);
Log.i("Id", Id);
Log.i("Image", Image);
Log.i("Album", Album);
Log.i("Thumbnail", Thumbnail);
db.addUser(Id, Title, Album, Thumbnail, Image);
Log.d("number of elements", String.valueOf(profile_counts));
} catch (JSONException e) {
e.printStackTrace();
progressDialog.dismiss();
}
}
adapter.notifyDataSetChanged();
progressDialog.dismiss();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("Volley", error.toString());
progressDialog.dismiss();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(jsonArrayRequest);
}
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = null;
if (connectivityManager != null) {
activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
}
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
}
Now I just want to know how do I populate the recyclerview from SQLite database, so far I have been able to get the data from remote server and save it in the SQLite database with the help of SqliteHandler class.This is my adapter class
public class MovieAdapter extends RecyclerView.Adapter<MovieAdapter.ViewHolder> {
private Context context;
private List<Movie> list;
private String link;
private imageDownload image;
MovieAdapter(Context context, List<Movie> list) {
this.context = context;
this.list = list;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(context).inflate(R.layout.list, parent, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(@NonNull final MovieAdapter.ViewHolder holder, int position) {
Movie movie = list.get(position);
holder.textTitle.setText(movie.getTitle());
holder.textId.setText(String.valueOf(movie.getId()));
holder.textThumb.setText(movie.getThumbnailurl());
holder.textAlbum.setText(String.valueOf(movie.getAlbumid()));
Picasso.with(context).load(movie.getImage())
.into(holder.photo);
holder.photo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
link = list.get(holder.getAdapterPosition()+1).getImage();
image = new imageDownload(context, holder.photo);
image.execute(link);
Log.e("image link", link);
Toast.makeText(context, "image clicked: " + holder.getAdapterPosition(), Toast.LENGTH_LONG).show();
}
});
}
@Override
public int getItemCount() {
return list.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
TextView textTitle, textId, textThumb, textAlbum;
ImageView photo;
ViewHolder(View itemView) {
super(itemView);
textTitle = itemView.findViewById(R.id.title_1);
textId = itemView.findViewById(R.id.id_1);
textThumb = itemView.findViewById(R.id.thumbnailurl_1);
textAlbum = itemView.findViewById(R.id.albumid_1);
photo = itemView.findViewById(R.id.imageview);
}
}
class imageDownload extends AsyncTask<String, Integer, Bitmap> {
Context context;
ImageView imageView;
Bitmap bitmap;
InputStream in = null;
//constructor.
imageDownload(Context context, ImageView imageView) {
this.context = context;
this.imageView = imageView;
}
@Override
protected void onPreExecute() {
}
@Override
protected Bitmap doInBackground(String... params) {
HttpURLConnection httpURLConnection = null;
try {
URL url = new URL(params[0]);
httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.connect();
in = httpURLConnection.getInputStream();
BufferedInputStream bufferedInputStream = new
BufferedInputStream(in);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (httpURLConnection != null) {
httpURLConnection.disconnect();
}
}
return bitmap;
}
@Override
protected void onPostExecute(Bitmap data) {
imageView.setImageBitmap(data);
try {
try {
saveImage(data);
} catch (MalformedURLException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// System.out.print(Log.e("Image Data",data.toString()));
}
private void saveImage(Bitmap data) throws FileNotFoundException, MalformedURLException {
File createFolder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "test");
File saveImage = new File(createFolder, "downloadedImage.jpg");
try {
OutputStream outputStream = new FileOutputStream(saveImage);
data.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
outputStream.flush();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Movie.class
public class Movie {
public String title;
public String getAlbumid() {
return albumid;
}
public void setAlbumid(String albumid) {
this.albumid = albumid;
}
public String getThumbnailurl() {
return thumbnailurl;
}
public void setThumbnailurl(String thumbnailurl) {
this.thumbnailurl = thumbnailurl;
}
public String albumid;
public String thumbnailurl;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
private int id;
private String image;
public Movie() {
}
public Movie(String title, String image, int id) {
this.title = title;
this.image = image;
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
