Android - Hide keyboard Programatically - Get data from internet class - checking network status

Android-AsyncTaskLoader.md

Asynctask

getting data from the internet using

see the NetworkUtils class to see how to get data from internet.

Hiding the keyboard Programatically

        //Hiding the keyboard after the button pressed.
        InputMethodManager inputManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        if (inputManager != null) {
            inputManager.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
        }

checking the network status

        //Getting the network info and connectivity state:
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = null;
        if (connectivityManager != null) {
            networkInfo = connectivityManager.getActiveNetworkInfo();
        }
        if (networkInfo != null && networkInfo.isConnected() && SEARCH_QUERY.length() != 0) {
            //Updating the text iews so that the user know what is going on.
            titleTextview.setText(R.string.loading);
            authorTetview.setText(R.string.please_wait);

            //Ask for the data over internet
            new FetchBook(titleTextview, authorTetview).execute(SEARCH_QUERY);
        } else {
            if (SEARCH_QUERY.length() == 0) {
                authorTetview.setText("");
                titleTextview.setText(R.string.no_search_term);
            } else {
                authorTetview.setText("");
                titleTextview.setText(R.string.no_connection);
            }
        }

FetchBook.java

package mohammad.samandari.whowroteit;

import android.net.Uri;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.TextView;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.lang.ref.WeakReference;

public class FetchBook extends AsyncTask<String, Void, String> {

    private static final String TAG = "Lord";

    // Base URL for Books API.
    private static final String BOOK_BASE_URL =  "https://www.googleapis.com/books/v1/volumes?";
    // Parameter for the search string.
    private static final String QUERY_PARAM = "q";
    // Parameter that limits search results.
    private static final String MAX_RESULTS = "maxResults";
    // Parameter to filter by print type.
    private static final String PRINT_TYPE = "printType";

    WeakReference<TextView> mTitleTextview, mAuthorTextview;

    FetchBook (TextView titleTextview, TextView authorTextview) {
        mTitleTextview = new WeakReference<>(titleTextview);
        mAuthorTextview = new WeakReference<>(authorTextview);
    }

    @Override
    protected String doInBackground (String... strings) {
        try {
            Uri buildUri = Uri.parse(BOOK_BASE_URL).buildUpon()
                    .appendQueryParameter(QUERY_PARAM, strings[0])
                    .appendQueryParameter(MAX_RESULTS, "10")
                    .appendQueryParameter(PRINT_TYPE, "books")
                    .build();
            return NetworkUtils.GetData(buildUri);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute (String s) {
        super.onPostExecute(s);

        try {
            JSONObject jsonObject = new JSONObject(s);
            JSONArray jsonArray = jsonObject.getJSONArray("items");
            int i = 0;
            String TITLE = null;
            String AUTHOR = null;

            while (i < jsonArray.length() &&
                   (AUTHOR == null && TITLE == null)) {
                // Get the current item information.
                JSONObject book = jsonArray.getJSONObject(i);
                JSONObject volumeInfo = book.getJSONObject("volumeInfo");

                // Try to get the author and title from the current item,
                // catch if either field is empty and move on.
                try {
                    TITLE = volumeInfo.getString("title");
                    AUTHOR = volumeInfo.getString("authors");
                } catch (Exception e) {
                    e.printStackTrace();
                }

                // Move to the next item.
                i++;
            }
            if (TITLE != null && AUTHOR != null) {
                mTitleTextview.get().setText(TITLE);
                mAuthorTextview.get().setText(AUTHOR);
            } else {
                mTitleTextview.get().setText(R.string.no_result);
                mAuthorTextview.get().setText("");
            }
        } catch (JSONException e) {
            e.printStackTrace();
            Log.e(TAG, "onPostExecute: ", e);
            // If onPostExecute does not receive a proper JSON string,
            // update the UI to show failed results.
            mTitleTextview.get().setText(R.string.no_result);
            mAuthorTextview.get().setText("");
        }
    }
}

MainActivity.java

package mohammad.samandari.whowroteit;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.hardware.input.InputManager;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "Lord";

    EditText searchEditText;
    TextView titleTextview, authorTetview;

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

        searchEditText = findViewById(R.id.searchEditText);
        titleTextview = findViewById(R.id.titleTextview);
        authorTetview = findViewById(R.id.authorTextview);

    }

    public void searchBook (View view) {
        // Get the search string from the input field.
        String SEARCH_QUERY = searchEditText.getText().toString();

        //Hiding the keyboard after the button pressed.
        InputMethodManager inputManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        if (inputManager != null) {
            inputManager.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
        }

        //Getting the network info and connectivity state:
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = null;
        if (connectivityManager != null) {
            networkInfo = connectivityManager.getActiveNetworkInfo();
        }
        if (networkInfo != null && networkInfo.isConnected() && SEARCH_QUERY.length() != 0) {
            //Updating the text iews so that the user know what is going on.
            titleTextview.setText(R.string.loading);
            authorTetview.setText(R.string.please_wait);

            //Ask for the data over internet
            new FetchBook(titleTextview, authorTetview).execute(SEARCH_QUERY);
        } else {
            if (SEARCH_QUERY.length() == 0) {
                authorTetview.setText("");
                titleTextview.setText(R.string.no_search_term);
            } else {
                authorTetview.setText("");
                titleTextview.setText(R.string.no_connection);
            }
        }




    }
}

NetworkUtils.java

package mohammad.samandari.whowroteit;

import android.net.Uri;
import android.util.Log;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;

public class NetworkUtils {
    private static final String TAG = "Lord";

    static String GetData (Uri uri) {
        HttpURLConnection httpURLConnection = null;
        BufferedReader reader = null;
        String RESULT = null;

        try {
            URL requestUrl = new URL(uri.toString());

            httpURLConnection = (HttpURLConnection) requestUrl.openConnection();
            httpURLConnection.setRequestMethod("GET");
            httpURLConnection.connect();

            // Get the InputStream.
            InputStream inputStream = httpURLConnection.getInputStream();

            // Create a buffered reader from that input stream.
            reader = new BufferedReader(new InputStreamReader(inputStream));

            // Use a StringBuilder to hold the incoming response.
            StringBuilder builder = new StringBuilder();

            String line;
            while ((line = reader.readLine()) != null) {
                builder.append(line);
                // Since it's JSON, adding a newline isn't necessary (it won't
                // affect parsing) but it does make debugging a *lot* easier
                // if you print out the completed buffer for debugging.
                builder.append("\n");
            }
            if (builder.length() == 0) {
                // Stream was empty. No point in parsing.
                return null;
            }

            RESULT = builder.toString();

        } catch (IOException e) {
            e.printStackTrace();
            Log.e(TAG, "getData: ", e);
        } finally {
            if (httpURLConnection != null) {
                httpURLConnection.disconnect();
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        Log.d(TAG, RESULT);

        return RESULT;
    }
}