TechieUpgrader Programming Blog - Tutorials about Angular, ReactJS, PHP, MySQL and Web Development: pdo

Today you gonna learn how to create a login activity that uses volley for request. Click here If you want more information about volley library.

To begin with, will first create a back-end using PHP and my SQL. I'm using wamp server to host the php scripts.

1. Backend - PHP, MYSQL, PDO

Project Structure:

i) fire up the server (wampserver for my case), open browser and go to localhost/phpmyadmin

ii) create a database androidmastermind,

iii) create a table login,

CREATE TABLE IF NOT EXISTS `login` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(30) NOT NULL,
  `password` varchar(50) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
)

INSERT INTO `login` (`id`, `username`, `password`, `created_at`)

 VALUES(1, 'admin@gmail.com', 'admin', '2016-06-22 09:34:13');

iv) Create constants.php file, this will hold all the variables that we will need to reuse.

<?php


define("USERNAME","username");

define("PASSWORD","password");

v) Create DbConnection.php file, this will handle the database connection and disconnection when needed.
* Remember to change the username and password*

<?php

    private static $dbName = 'androidmastermind';

    private static $dbHost = 'localhost';

    private static $dbUsername = 'kevynashinski';

    private static $dbUserPassword = 'elegant';
    private static $cont = null;
    public function __construct(){
    }

    public static function connect(){
        // One connection through whole application

        if (null == self::$cont) {
            try {
                self::$cont = new PDO("mysql:host=" . self::$dbHost . ";"

                 . "dbname=" . self::$dbName, self::$dbUsername, self::$dbUserPassword);

                self::$cont->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

            } catch (PDOException $e) {
                die($e->getMessage());            }
        }
        return self::$cont;    }

    public static function disconnect(){
        self::$cont = null;    }
}

vi) Finally create login.php file, this will authenticate the user, by receiving thus username and password through POST.

<?php

include 'DbConnection.php';

include 'constants.php';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {

    $username = $_REQUEST[USERNAME];

    $password = $_REQUEST[PASSWORD];
//    open connection

    $conn = DatabaseConnection::connect();
    $sql = "select * from login WHERE username='$username' AND password='$password'";
//    check if a row exists with the credentials

    if ($conn->query($sql)->rowCount() > 0) {
//        shows there's a record

        echo 1;

    } else {
//        shows there's no such record

        echo 0;

    }
} else{
//    shows that nothing was posted

    echo 2;

* The index.php serves the purpose of testing our database connection.

<?php
include 'DbConnection.php';
$conn=DatabaseConnection::connect();
if($conn){
    echo "Ready to Roll!!!";

}else{
    echo "connection Error".$conn->errorInfo();

2. Frontend - Android

Project Structure:

i) Create a new android project, name it AndroidLogin

ii) Import volley library to your build.gradle (app:module)

compile group: 'com.mcxiaoke.volley', name: 'library', version: '1.0.19'

ii) Create App.java in the package, this class extends Application, it holds the initialization of the app configurations, in our case volley initialization.

package com.androidmatermind.androidlogin;

import android.app.Application;
import android.text.TextUtils;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;

/** * Created by Kevynashinski on 6/23/2016. */

public class App extends Application{
    public static final String TAG = "androidlogin";

    private ImageLoader mImageLoader;

    private RequestQueue mRequestQueue;
    private static App mInstance;

    @Override    public void onCreate() {
        super.onCreate();
        mInstance = this;
    }


    public static synchronized App getInstance() {
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getBaseContext());
        }

        return mRequestQueue;
    }

    public <T> void addToRequestQueue(Request<T> req, String tag) {
        // set the default tag if tag is empty

        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
        getRequestQueue().add(req);
    }

    public <T> void addToRequestQueue(Request<T> req) {
        req.setTag(TAG);
        getRequestQueue().add(req);
    }

    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
}

iii) Create another file, AppConfig.java, this holds the server link

package com.androidmatermind.androidlogin;

/** * Created by muus on 6/23/2016. */

public final class AppConfig {

    public static final String SERVER_URL="http://192.168.56.1/androidlogin/";
    public static final String URL_LOGIN=SERVER_URL+"login.php";
}

iv) InternetConnection.java class, will help us check if internet is available before login begins

package com.androidmatermind.androidlogin;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

/** * Created by kevynashinski on 11/9/2015. */

public class InternetConnection {

    Context context;

    public InternetConnection(Context context) {
        this.context = context;
    }

    public boolean isInternetAvailable() {
        ConnectivityManager connectivityManager = (ConnectivityManager)

 context.getSystemService(Context.CONNECTIVITY_SERVICE);

//        boolean isWiFi = activeNetwork.getType() == ConnectivityManager.TYPE_WIFI;

        NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }
}

v) Under the MainActivity.java, will when a user click sign in button, will first check if internet is available, then carry out the login operation. The email and password will also be validated

package com.androidmatermind.androidlogin;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.CursorLoader;
import android.content.Loader;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.annotation.NonNull;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.util.Log;
import android.util.Patterns;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static android.Manifest.permission.READ_CONTACTS;

/** * A login screen that offers login via email/password. */
public class MainActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {

    private static final int REQUEST_READ_CONTACTS = 0;

    // UI references.    private AutoCompleteTextView mEmailView;
    private EditText mPasswordView;
    private View mProgressView;
    private View mLoginFormView;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Set up the login form.
        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
        populateAutoComplete();

        mPasswordView = (EditText) findViewById(R.id.password);

        Button signInButton = (Button) findViewById(R.id.sign_in_button);
        assert signInButton != null;
        signInButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                if(new InternetConnection(getBaseContext()).isInternetAvailable())
                attemptLogin();
                else {
                    Toast.makeText(getBaseContext(),"Check your internet connection",
Toast.LENGTH_LONG).show();
                }
            }
        });

        mLoginFormView = findViewById(R.id.login_form);
        mProgressView = findViewById(R.id.login_progress);
    }

    private void populateAutoComplete() {
        if (!mayRequestContacts()) {
            return;
        }

        getLoaderManager().initLoader(0, null, this);
    }

    private boolean mayRequestContacts() {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
            return true;
        }
        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
            return true;
        }
        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
                    .setAction(android.R.string.ok, new View.OnClickListener() {
                        @Override
                        @TargetApi(Build.VERSION_CODES.M)
                        public void onClick(View v) {
                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
                        }
                    });
        } else {
            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
        }
        return false;
    }

    /**     * Callback received when a permissions request has been completed.     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        if (requestCode == REQUEST_READ_CONTACTS) {
            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                populateAutoComplete();
            }
        }
    }


    /**     * Attempts to sign in or register the account specified by the login form.
     * If there are form errors (invalid email, missing fields, etc.), the     
     * errors are presented and no actual login attempt is made.
     */
    private void attemptLogin() {
        // Reset errors.
        mEmailView.setError(null);
        mPasswordView.setError(null);

        // Store values at the time of the login attempt.
        String email = mEmailView.getText().toString();
        String password = mPasswordView.getText().toString();

        boolean cancel = false;
        View focusView = null;

        // Check for a valid password, if the user entered one.
        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
            mPasswordView.setError(getString(R.string.error_invalid_password));
            focusView = mPasswordView;
            cancel = true;
        }

        // Check for a valid email address.
        if (TextUtils.isEmpty(email)) {
            mEmailView.setError(getString(R.string.error_field_required));
            focusView = mEmailView;
            cancel = true;
        } else if (!isEmailValid(email)) {
            mEmailView.setError(getString(R.string.error_invalid_email));
            focusView = mEmailView;
            cancel = true;
        }

        if (cancel) {
            // There was an error; don't attempt login and focus the first
            // form field with an error.
            focusView.requestFocus();
        } else {
            // Show a progress spinner, and kick off a background task to
            // perform the user login attempt.
            showProgress(true);
            login(email,password);
        }
    }

    private void login(final String email, final String password) {
        StringRequest strReq = new StringRequest(Request.Method.POST,
                AppConfig.URL_LOGIN, new Response.Listener<String>() {

            @Override
            public void onResponse(String response) {
                Log.d(App.TAG, "Login Response: " + response);

                showProgress(false);

                if(response.equalsIgnoreCase("1")){
                    Toast.makeText(getBaseContext(),"Login Success!!!",Toast.LENGTH_LONG).show();
                }else if(response.equalsIgnoreCase("0")){
                    Toast.makeText(getBaseContext(),"Invalid username or password",
Toast.LENGTH_LONG).show();
                }else if(response.equalsIgnoreCase("2")){
                    Toast.makeText(getBaseContext(),"Server Error!",Toast.LENGTH_LONG).show();
                }
            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {

                showProgress(false);

                Log.e(App.TAG, "Login Error: " + error.getMessage());
            }
        }) {

            @Override
            protected Map<String, String> getParams() {
                // Posting parameters to login url
                Map<String, String> params = new HashMap<>();
                params.put("username", email);
                params.put("password", password);

                return params;
            }
        };

        // Adding request to request queue
        App.getInstance().addToRequestQueue(strReq);
    }

    private boolean isEmailValid(String email) {
        //TODO: Replace this with your own logic
        return Patterns.EMAIL_ADDRESS.matcher(email).matches();
    }

    private boolean isPasswordValid(String password) {
        //TODO: Replace this with your own logic
        return password.length() > 4;
    }

    /**     * Shows the progress UI and hides the login form.
     */    
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
    private void showProgress(final boolean show) {
        // On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
        // for very easy animations. If available, use these APIs to fade-in
        // the progress spinner.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
  int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);

            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
            mLoginFormView.animate().setDuration(shortAnimTime).alpha(
                    show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
                }
            });

            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
            mProgressView.animate().setDuration(shortAnimTime).alpha(
                    show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
                }
            });
        } else {
            // The ViewPropertyAnimator APIs are not available, so simply show
            // and hide the relevant UI components.
            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
        }
    }

    @Override
    public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
        return new CursorLoader(this,
                // Retrieve data rows for the device user's 'profile' contact.
                Uri.withAppendedPath(ContactsContract.Profile.CONTENT_URI,
                        ContactsContract.Contacts.Data.CONTENT_DIRECTORY), ProfileQuery.PROJECTION,

                // Select only email addresses.
                ContactsContract.Contacts.Data.MIMETYPE +
                        " = ?", new String[]{ContactsContract.CommonDataKinds.Email
                .CONTENT_ITEM_TYPE},

                // Show primary email addresses first. Note that there won't be
                // a primary email address if the user hasn't specified one.
                ContactsContract.Contacts.Data.IS_PRIMARY + " DESC");
    }

    @Override
    public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
        List<String> emails = new ArrayList<>();
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            emails.add(cursor.getString(ProfileQuery.ADDRESS));
            cursor.moveToNext();
        }

        addEmailsToAutoComplete(emails);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> cursorLoader) {

    }

    private void addEmailsToAutoComplete(List<String> emailAddressCollection) {
        //Create adapter to tell the AutoCompleteTextView what to show in its dropdown list.
        ArrayAdapter<String> adapter =
                new ArrayAdapter<>(MainActivity.this,
                android.R.layout.simple_dropdown_item_1line, emailAddressCollection);

        mEmailView.setAdapter(adapter);
    }


    private interface ProfileQuery {
        String[] PROJECTION = {
                ContactsContract.CommonDataKinds.Email.ADDRESS,
                ContactsContract.CommonDataKinds.Email.IS_PRIMARY,
        };

        int ADDRESS = 0;
        int IS_PRIMARY = 1;
    }

}

vi) Add the following codes to the activity_main.xml

<LinearLayout

 xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:gravity="center_horizontal"

    android:orientation="vertical"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity">

    <!-- Login progress -->

    <ProgressBar

        android:id="@+id/login_progress"

        style="?android:attr/progressBarStyleLarge"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginBottom="8dp"

        android:visibility="gone" />

    <ScrollView

        android:id="@+id/login_form"

        android:layout_width="match_parent"

        android:layout_height="match_parent">

        <LinearLayout

            android:id="@+id/email_login_form"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:orientation="vertical">

            <android.support.design.widget.TextInputLayout

                android:layout_width="match_parent"

                android:layout_height="wrap_content">

                <AutoCompleteTextView

                    android:id="@+id/email"

                    android:layout_width="match_parent"

                    android:layout_height="wrap_content"

                    android:hint="Email Address"

                    android:inputType="textEmailAddress"

                    android:maxLines="1"

                    android:singleLine="true" />

            </android.support.design.widget.TextInputLayout>

            <android.support.design.widget.TextInputLayout

                android:layout_width="match_parent"

                android:layout_height="wrap_content">

                <EditText

                    android:id="@+id/password"

                    android:layout_width="match_parent"

                    android:layout_height="wrap_content"

                    android:hint="password"

                    android:inputType="textPassword"

                    android:maxLines="1"

                    android:singleLine="true" />

            </android.support.design.widget.TextInputLayout>

            <Button

                android:id="@+id/sign_in_button"

                style="?android:textAppearanceSmall"

                android:layout_width="match_parent"

                android:layout_height="wrap_content"

                android:layout_marginTop="16dp"

                android:text="Sign in"

                android:textStyle="bold" />

        </LinearLayout>
    </ScrollView>
</LinearLayout>

vii) Run the project,
a) When login success.

b) When login failure.

Wednesday 29 May 2019

Build Your Own Video Sharing Website LikeYouTube

What is this article about?
This article will teach you step by step how to create a website similar to YouTube. So if you've ever wanted to launch a YouTube like site, you will be able to at the end of the article.

Monetizing Your Site
You will learn how to monetize your site with Google Adsense or banners simply by inserting your codes in whatever position you want to show ads. This will give you complete control over what ads show on your website.

Website and Video Optimization
This article will teach you how to optimize your site, menus, videos, and content pages. This will increase your visibility on search engines like Google, Bing and Yahoo!.

and much more!

Coming Soon

Sunday 24 September 2017

Create Android Studio login: using volley php mysql pdo

1. Backend - PHP, MYSQL, PDO

Project Structure:

2. Frontend - Android

search

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Categories

Search Bar

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Most Popular

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Wednesday 29 May 2019

Build Your Own Video Sharing Website LikeYouTube

What is this article about?This article will teach you step by step how to create a website similar to YouTube. So if you've ever wanted to launch a YouTube like site, you will be able to at the end of the article.

Monetizing Your SiteYou will learn how to monetize your site with Google Adsense or banners simply by inserting your codes in whatever position you want to show ads. This will give you complete control over what ads show on your website.

Website and Video OptimizationThis article will teach you how to optimize your site, menus, videos, and content pages. This will increase your visibility on search engines like Google, Bing and Yahoo!.

and much more!

Coming Soon

Sunday 24 September 2017

Create Android Studio login: using volley php mysql pdo

1. Backend - PHP, MYSQL, PDO

Project Structure:

2. Frontend - Android

search

Technology

Categories

Search Bar

Advertise Here

Most Popular

Find Us On Facebook

Contact Form

Join with us!

What is this article about?
This article will teach you step by step how to create a website similar to YouTube. So if you've ever wanted to launch a YouTube like site, you will be able to at the end of the article.

Monetizing Your Site
You will learn how to monetize your site with Google Adsense or banners simply by inserting your codes in whatever position you want to show ads. This will give you complete control over what ads show on your website.

Website and Video Optimization
This article will teach you how to optimize your site, menus, videos, and content pages. This will increase your visibility on search engines like Google, Bing and Yahoo!.