It takes a long time to load large data in recyclerview - text-files

Question

I have 11 text files each containing 50-60 lines. I have read all the files and showed in the recyclerview. I used asynctask to track the progress through the progress bar. I have used log too to see the read lines. I have found that reading is taking short time but after reading, it takes 5-6 seconds to show data in the recyclerview. Why is this causing? What should i do to handle this? Why should i do if there are thousands of text files?
Codes reading files and binding
AsyncTask<Void,Void,Void> task = new AsyncTask<Void, Void, Void>() {
ProgressDialog progressDialog;
#Override
protected void onPreExecute() {
progressDialog = ProgressDialog.show(GrammerDetails.this,
"Loading", "Please Wait for a while");
}
#Override
protected Void doInBackground(Void... voids) {
getFromFilesbagdhara(id,realm);
SharedPreferences.Editor editor = preferences.edit();
editor.putBoolean("first_bagdhara",false);
editor.apply();
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
inflateData(listGrammerItem);
progressDialog.dismiss();
}
}.execute();
private void getFromFilesbagdhara(String id, Realm realm) {
String directory = "Grammer/Bagdhara";
AssetManager man = getAssets();
BufferedReader reader = null;
try {
String[] files = man.list(directory);
for (int i =0;i<files.length;i++){
String fileName = files[i];
reader = new BufferedReader(
new InputStreamReader(getAssets().open(directory+"/" + fileName),
"UTF-8"));
String line;
Log.e("File",files[i]);
while ((line = reader.readLine()) != null) {
Log.e("line",line);
// String[] text = line.split(" ");
String a = line.substring(0,line.indexOf("(")-1);
String b = line.substring(line.indexOf("(")+1,line.indexOf(")"));
String wordOne = a;
// String dummyTwo = text[1];
String wordTwo = b; //dummyTwo.substring(1,dummyTwo.length()-1);
final ClassGrammerItem classGrammerItem = new ClassGrammerItem(wordOne,wordTwo,id);
listGrammerItem.add(classGrammerItem);
}
}
} catch (IOException e) {
e.printStackTrace();
}finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
//log the exception
}
}
}
}
private void inflateData(RealmList<ClassGrammerItem> listGrammerItem) {
AdapterGrammerItem adapter = new AdapterGrammerItem(listGrammerItem, GrammerDetails.this);
recyclerView.setAdapter(adapter);
}
Adapter:
public class AdapterGrammerItem extends RecyclerView.Adapter<AdapterGrammerItem
.ViewHolderAdapterRecycler> {
RealmList<ClassGrammerItem> activityList = new RealmList<ClassGrammerItem>();
Context context;
private LayoutInflater layoutInflater;
public AdapterGrammerItem(RealmList<ClassGrammerItem> activityList, Context context) {
this.activityList = activityList;
this.context = context;
layoutInflater = LayoutInflater.from(context);
}
#Override
public AdapterGrammerItem.ViewHolderAdapterRecycler onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.recycler_grammer_item, parent, false);
AdapterGrammerItem.ViewHolderAdapterRecycler viewHolder = new AdapterGrammerItem.ViewHolderAdapterRecycler(view);
return viewHolder;
}
#Override
public void onBindViewHolder(AdapterGrammerItem.ViewHolderAdapterRecycler holder, int position) {
ClassGrammerItem currentItem = activityList.get(position);
holder.wordOne.setText(currentItem.getWordOne());
holder.wordTwo.setText(currentItem.getWordTwo());
}
#Override
public int getItemCount() {
return activityList.size();
}
public class ViewHolderAdapterRecycler extends RecyclerView.ViewHolder {
MyTextView wordOne, wordTwo;
public ViewHolderAdapterRecycler(View itemView) {
super(itemView);
wordOne = (MyTextView) itemView.findViewById(R.id.wordOne);
wordTwo = (MyTextView) itemView.findViewById(R.id.wordTwo);
}
}
}