initLoader

[Pranshu04]

If I search for the first time with book name, it gives the correct result but on the second time if I search any other keywords than it doesn't respond.

                                      MainActivity.class

package com.example.prans.booklist;

import android.app.LoaderManager;
import android.content.Context;
import android.content.Intent;
import android.content.Loader;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<List> {

private BookAdapter mAdapter;

private static final String LOG_TAG = MainActivity.class.getName();
private String GOOGLE_REQUEST_URL =
        "https://www.googleapis.com/books/v1/volumes?q=";

private ListView bookListView;
TextView mEmptyStateTextView;

private static final int BOOK_LOADER_ID = 1;

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

    Log.d(LOG_TAG, "onCreate.....");
    mEmptyStateTextView = findViewById(R.id.empty_view);
    final EditText search_query = findViewById(R.id.etSearch);
    Button mSearch = findViewById(R.id.btnSearch);
    mSearch.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String etQuery = search_query.getText().toString();
            if (etQuery.length() == 0) {
                etQuery.equalsIgnoreCase("");
                search_query.setError("Fields cannot be empty");


            } else {

                etQuery = etQuery.replaceAll(" ", "+");
                GOOGLE_REQUEST_URL = "https://www.googleapis.com/books/v1/volumes?q=" + etQuery;

                ConnectivityManager connMgr = (ConnectivityManager)
                        getSystemService(Context.CONNECTIVITY_SERVICE);

                NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();

                if (networkInfo != null && networkInfo.isConnected()) {

                    LoaderManager loaderManager = getLoaderManager();
                    loaderManager.initLoader(BOOK_LOADER_ID, null, MainActivity.this); 

                } else {
                    Toast.makeText(MainActivity.this, "No internet available", Toast.LENGTH_SHORT).show();
                }

            }

        }
    });
    bookListView = findViewById(R.id.list);
    mAdapter = new BookAdapter(this, new ArrayList<Book>());
    bookListView.setAdapter(mAdapter);

    bookListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Book current_book = mAdapter.getItem(position);
            Uri bookUri = Uri.parse(current_book.getUrl());
            Intent book_intent = new Intent(Intent.ACTION_VIEW, bookUri);
            startActivity(book_intent);
        }
    });

}

@Override
public Loader<List<Book>> onCreateLoader(int i, Bundle bundle) {

    Log.d(LOG_TAG, "onCreateLoader.....");
    return new BookLoader(this, GOOGLE_REQUEST_URL);
}

@Override
public void onLoadFinished(Loader<List<Book>> loader, List<Book> books) {

    Log.d(LOG_TAG, " onLoadFinished.....");
    mAdapter.clear();
    if (books != null && !books.isEmpty()) {
        mAdapter.setNotifyOnChange(true);
        mAdapter.addAll(books);
    }
}

@Override
public void onLoaderReset(Loader<List<Book>> loader) {
    Log.d(LOG_TAG, " onLoaderReset.....");

    mAdapter.clear();
    mAdapter.notifyDataSetChanged();
}  }