Android MySQL - Insert/Save - Material EditTexts

android networking

Android MySQL Insert tutorial.In this tutorial,we look at Android MySQL database,saving data to MySQL. We insert data from edittexts into mysql.

  • We use HttpURLConnection class. It will be our HTTP Client
  • We save to MySQL via PHP Code. PHP will be our server side language while mysql our database.
  • We are making a HTTP POST Request. Basically we are sending data to our server.
  • We write through an outputstream,but also read a response from server via inputstream.
  • We do these in background thread using asynctask.

We are using Java programming language.

Introduction to Android

You will write your android application in either Java or Kotlin. However these days there are several frameworks like Xamarin, Flutter and React Native but Java and Kotlin are the two native languages.

Once you've written your app, the Android SDK tools will compile the code, data and resource files into an APK (Android package).

In most cases a single APK file will contain all the content of the app.

Each Android App normally runs on its own virtual machine(VM). This implies that the app can run in isolation from other apps.

Android system applies the principle of least privilege. This means that each app will only have access to the components it requires to do its work,and no more.

However, there are ways for an app to share data with other apps, such as by sharing Linux user id between app, or apps can request permission to access device data like SD card, contacts etc.

What is a Database?

A database, generally speaking, refers to any organized collection of data

There are several types of databases:

  1. Flat file databases ― these store data sequentially, often in plain text files.

  2. Hierarchical databases ― these organize data in parent/child relationships.

  3. Key-value/document-oriented databases ― these store free-form data indexed by a key or hash value.

  4. Relational databases ― these organize data in rows and tables. This is the most popular and is what we use in most of our examples.

What is MySQL ?

MySQL is an open source, multithreaded, relational database management system created by Michael "Monty" Widenius in 1995.

Many businesses these days develop and maintain custom software with MySQL. Additionally, majority of the most popular websites(e.g Wikipedia) and software use MySQL for their database.

One of the most prominent features of MySQL is its speed and scalability. Together with MariaDB, MySQL's identical twin brother/sister, tends of thousands of rows and billions of rows of data can efficiently be handled.

However, you can also use MySQL for small amounts of data, like we will do to store our PDF documents in this android pdf viewer app we will create.

Why do Alot of People Choose MySQL?

There are many RDBMS(Relational Database Management System) databases. However MySQL is the most popular.

This is because of the following factors:

  1. Speed. MySQL is fast. Its developers claim that MySQL is about the fastest database system you can get.You can investigate this claim by visiting here, a performance-comparison page on the MySQL Web site.

  2. Ease of use. Even though MySQL is highly performant, it's relative a simple database system. Setting it up and Administering it is much less complex than other large systems.

  3. Query language support. MySQL also provides support for SQL(Structured Query Language). SQL is the standard language of choice for almost all modern database systems.

  4. Capability. The MySQL server is multi-threaded. This implies that many clients can connect to it at the same time. Each client can use multiple databases simultaneously.

  5. Connectivity and security. MySQL is fully networked, and databases can be accessed from anywhere on the Internet. Hence you can share your data with anyone, anywhere. But MySQL has access control so that one person who shouldn’t see another’s data cannot.To provide additional security, MySQL supports encrypted connections using the Secure Sockets Layer (SSL) protocol.

  6. Availability and cost. MySQL is an Open Source project available under multiple licensing terms. First, it is available under the terms of the GNU General Public License (GPL).This means that MySQL is available without cost for most in-house uses. Second, for organizations that prefer or require formal arrangements or that do not want to be bound by the conditions of the GPL, commercial licenses are available.

What is MySQLi?

MySQLi is a PHP extension which allows us to access the functionality provided by MySQL 4.1 and above.

As an extension, mysqli exposes APIs to the PHP programmer, to allow us work with MySQL database programmatically.

Normally there are three ways(APIs) of working with MySQL from database:

  1. PHP MySQLi extension.
  2. PHP MySQL extension.
  3. PHP Data Objects(PDO).

In this class we will use the most commonly used API which is mysqli.

Advantages of MySQLi

MySQLi is the most popular API for working with MySQL database because of the following reasons:

  1. Provision of both Object Oriented and Procedural Interfaces.
  2. Embedded Server support.
  3. Support for Prepared Statements.
  4. Ability to use Multiple Statements.
  5. Transactions support.

etc

You can find more information about mysqli here.

Introduction to PHP?

PHP is a popular general-purpose scripting language that is especially suited to web development.

Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world.

PHP Hello World
<?php
echo "Hello world";

PHP's website is here.

Classes

Class definitions start with the keyword class, followed by a class identifier, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class.

A class may contain its own constants, variables (called "properties"), and functions (called "methods").

Here's a simple class definition in PHP:

<?php
class HelloClass
{
    // property declaration
    public $var = 'a default value';

    // method declaration
    public function displayVar() {
        echo $this->var;
    }
}
?>

You can then create an instance:

<?php
$h = new HelloClass();

// This can also be done with a variable:
$className = 'HelloClass';
$h = new $className(); // new HelloClass()
?>

We will be working with PHP in an Object Oriented manner.

Introduction to HttpURLConnection

HttpUrlconnection is a UrlConnection for HTTP used to send as well receive data over the web. These data may be of any type and length.

HttpURLConnection was added in android 1.0 and is a URLConnection with support for HTTP-specific features. Like its parent URLConnection, it resides in the java.net package. This class allows us do networking easily and is the standard networking library in android.

HttpUrlConnection can also be used to send and receive streams whose length isn’t known in advance.

To be used,we obtain a new HttpUrlconnection object by calling url.openConnection() and casting to HttpUrlConnection.

If we open a connction to a url with "https" scheme,this returns HttpsUrlConnection.

Here is a simple usage of HttpURLConnection to download a webpage:

   URL url = new URL("http://www.google.com/");
   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
     InputStream in = new BufferedInputStream(urlConnection.getInputStream());
     readStream(in);
   } finally {
     urlConnection.disconnect();
   }

For example, to retrieve the webpage at http://www.android.com/:

   URL url = new URL("http://www.android.com/");
   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
     InputStream in = new BufferedInputStream(urlConnection.getInputStream());
     readStream(in);
   } finally {
     urlConnection.disconnect();
   }
Posting Content

To post some content to a web server, first you have to configure the connection for output using setDoOutput(true).

For best performance, you should call either setFixedLengthStreamingMode(int) when the body length is known in advance, or setChunkedStreamingMode(int) when it is not. Otherwise HttpURLConnection will be forced to buffer the complete request body in memory before it is transmitted, wasting (and possibly exhausting) heap and increasing latency.

 HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
     urlConnection.setDoOutput(true);
     urlConnection.setChunkedStreamingMode(0);

     OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
     writeStream(out);

     InputStream in = new BufferedInputStream(urlConnection.getInputStream());
     readStream(in);
   } finally {
     urlConnection.disconnect();
   }
HTTP Authentication

HttpURLConnection supports HTTP basic authentication. You can use Authenticator to set the VM-wide authentication handler:

  Authenticator.setDefault(new Authenticator() {
     protected PasswordAuthentication getPasswordAuthentication() {
       return new PasswordAuthentication(username, password.toCharArray());
     }
   });
Sessions with Cookies

To establish and maintain a potentially long-lived session between client and server, HttpURLConnection includes an extensible cookie manager. Enable VM-wide cookie management using CookieHandler and CookieManager:

  CookieManager cookieManager = new CookieManager();
   CookieHandler.setDefault(cookieManager);

Video Tutorial(ProgrammingWizards TV Channel)

Well we have a video tutorial as an alternative to this. If you prefer tutorials like this one then it would be good you subscribe to our YouTube channel.

Basically we have a TV for programming where do daily tutorials especially android.

Full Code

In this tutorial we want to see how save or insert data from an edittext to mysql database.

Android MySQL Insert Save

We are using httpurlconnection as our http client. The user will type data then click send to send the data via HTTP.

Our server side language is PHP while our database is mysql.

MySQL table Structure

Here's our mysql table:

Android PHP MySQL

1. PHP Code

Here's our php code:

<?php
$host='127.0.0.1';
$username='root';
$pwd='';
$db="spacecraftDB";
$con=mysqli_connect($host,$username,$pwd,$db) or die('Unable to connect');
if(mysqli_connect_error($con))
{
    echo "Failed to Connect to Database ".mysqli_connect_error();
}
$name=$_POST['name'];
$propellant=$_POST['propellant'];
$description=$_POST['description'];
$sql="INSERT INTO spacecraftTB(Name,Propellant,Description) VALUES('$name','$propellant','$description')";
$result=mysqli_query($con,$sql);
if($result)
{
    echo ('Successfully Saved........');

}else
{
    echo('Not saved Successfully............');

}
mysqli_close($con);
?>
2. Java Code.

Android apps can be mainly written in Java or Kotlin. These days however there are many frameworks like Flutter also which use languages like Dart.

In this class we are using Java programming language.

We will have these classes in our project.

(a). Our Spacecraft Class

This is our data object representing a single spacecraft.

package com.tutorials.hp.androidmdmysqlsave.mDataObject;

public class Spacecraft {

    int id;
    String name;
    String propellant;
    String description;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPropellant() {
        return propellant;
    }

    public void setPropellant(String propellant) {
        this.propellant = propellant;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}
(b). Our DataPackager Class
  • Basically,we package our data here for sending.
  • First we add them to a JSON Object.
  • Then we encode them into UTF-8 format using URLEncorder class.
  • Then we return it as a string ready to be written over the network.
package com.tutorials.hp.androidmdmysqlsave.mMySQL;

import com.tutorials.hp.androidmdmysqlsave.mDataObject.Spacecraft;

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

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Iterator;

public class DataPackager {

    Spacecraft spacecraft;

    public DataPackager(Spacecraft spacecraft) {
        this.spacecraft = spacecraft;
    }

    public String packData()
    {
        JSONObject jo=new JSONObject();
        StringBuffer sb=new StringBuffer();

        try {
            jo.put("Name",spacecraft.getName());
            jo.put("Propellant",spacecraft.getPropellant());
            jo.put("Description",spacecraft.getDescription());

            Boolean firstvalue=true;
            Iterator it=jo.keys();

            do {
                String key=it.next().toString();
                String value=jo.get(key).toString();

                if(firstvalue)
                {
                    firstvalue=false;
                }else
                {
                    sb.append("&");
                }

                sb.append(URLEncoder.encode(key,"UTF-8"));
                sb.append("=");
                sb.append(URLEncoder.encode(value,"UTF-8"));

            }while (it.hasNext());

            return sb.toString();

        } catch (JSONException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }
}
(c). Our Connector Class
package com.tutorials.hp.androidmdmysqlsave.mMySQL;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class Connector {

    public static HttpURLConnection connect(String urlAddress)
    {
        try {

            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            //SET PROPS
            con.setRequestMethod("POST");
            con.setConnectTimeout(20000);
            con.setReadTimeout(20000);
            con.setDoInput(true);
            con.setDoOutput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

}
(d). Our Sender Class
  • Yes,its our Sender class.To send us our data.
  • We send our data in a background thread using AsyncTask,the super class of this sender class.
  • While sending data in background,we show our Progressdialog,starting it in onPreExcecute() and dismissing immediately onPostExecute() is called.
  • We establish an outputStream,write to it using OutputStreamWriter().
  • The OutputStreamWriter() instance,we pass to BufferedWriter() instance.
  • The bufferedWriter() instance writes our data.
  • We then read the server response using bufferedreader instance.
package com.tutorials.hp.androidmdmysqlsave.mMySQL;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.EditText;
import android.widget.Toast;

import com.tutorials.hp.androidmdmysqlsave.mDataObject.Spacecraft;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;

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

    Context c;
    String urlAddress;
    EditText nameTxt,propellantTxt,descTxt;

    Spacecraft spacecraft;

    ProgressDialog pd;

    public Sender(Context c, String urlAddress, EditText nameTxt, EditText propellantTxt, EditText descTxt) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.nameTxt = nameTxt;
        this.propellantTxt = propellantTxt;
        this.descTxt = descTxt;

        spacecraft=new Spacecraft();
        spacecraft.setName(nameTxt.getText().toString());
        spacecraft.setPropellant(propellantTxt.getText().toString());
        spacecraft.setDescription(descTxt.getText().toString());
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        pd=new ProgressDialog(c);
        pd.setTitle("Send");
        pd.setMessage("Sending...Please wait");
        pd.show();
    }

    @Override
    protected String doInBackground(Void... params) {
        return this.send();
    }

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

        pd.dismiss();

        if(s==null)
        {
            Toast.makeText(c,"Unsuccessful,Null returned",Toast.LENGTH_SHORT).show();
        }else
        {
            if(s=="Bad Response")
            {
                Toast.makeText(c,"Unsuccessful,Bad Response returned",Toast.LENGTH_SHORT).show();

            }else
            {
                Toast.makeText(c,"Successfully Saved",Toast.LENGTH_SHORT).show();

                //CLEAR UI
                nameTxt.setText("");
                propellantTxt.setText("");
                descTxt.setText("");
            }
        }

    }

    private String send()
    {
        HttpURLConnection con=Connector.connect(urlAddress);
        if(con==null)
        {
            return null;
        }

        try {

            OutputStream os=con.getOutputStream();

            //WRITE
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(os,"UTF-8"));
            bw.write(new DataPackager(spacecraft).packData());

            bw.flush();
            //RELEASE
            bw.close();
            os.close();

            //SUCCESS OR NOT??
            int responseCode=con.getResponseCode();
            if(responseCode==con.HTTP_OK)
            {
                BufferedReader br=new BufferedReader(new InputStreamReader(con.getInputStream()));
                StringBuffer response=new StringBuffer();

                String line;
                while ((line=br.readLine()) != null)
                {
                    response.append(line);
                }

                br.close();
                return response.toString();
            }else {
                return "Bad Response";
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }
}
(d). Our MainActivity
  • Launcher activity.
  • Initialize UI like EditTexts.
  • Starts the sender Asynctask on button click,passing on urladdress and edittext.
package com.tutorials.hp.androidmdmysqlsave;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;

import com.tutorials.hp.androidmdmysqlsave.mMySQL.Sender;

public class MainActivity extends AppCompatActivity {

    String urlAddress="http://10.0.2.2/android/spacecraft.php";
    EditText nameTxt,propellantTxt,descTxt;
    Button saveBtn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        nameTxt= (EditText) findViewById(R.id.nameEditTxt);
        propellantTxt= (EditText) findViewById(R.id.propellantEditTxt);
        descTxt= (EditText) findViewById(R.id.descEditTxt);
        saveBtn= (Button) findViewById(R.id.saveBtn);

        saveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Sender s=new Sender(MainActivity.this,urlAddress,nameTxt,propellantTxt,descTxt);
                s.execute();
            }
        });

    }

}

3. Our Layouts

(a). activity_main.xml

This layout will get inflated into the main activity's user interface. This will happen via the Activity's setContentView() method which will require us to pass it the layout.

We will do so inside the onCreate() method of Activity.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.tutorials.hp.androidmdmysqlsave.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

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

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>
content_main.xml
  • Our layout.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.tutorials.hp.androidmdmysqlsave.MainActivity"
    tools:showIn="@layout/activity_main">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="?attr/actionBarSize"
        android:orientation="vertical"
        android:paddingLeft="15dp"
        android:paddingRight="15dp"
        android:paddingTop="50dp">

        <android.support.design.widget.TextInputLayout
            android:id="@+id/nameLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/nameEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:singleLine="true"
                android:hint= "Name" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/propellantLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/propellantEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"

                android:hint="Propellant" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/descLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/descEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"

                android:hint="Description" />

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

        <Button android:id="@+id/saveBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Save"
            android:clickable="true"
            android:background="@color/colorAccent"
            android:layout_marginTop="40dp"
            android:textColor="@android:color/white"/>

    </LinearLayout>
</RelativeLayout>

4. AndroidManifest.xml

Remember to add permission for internet in your manifest file.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.tutorials.hp.mysqlinsert">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

5. Download

Hey,everything is in source code reference that is well commented and easy to understand and can be downloaded below.

Also check our video tutorial it's more detailed and explained in step by step.

No. Location Link
1. GitHub Direct Download
2. GitHub Browse
3. YouTube Video Tutorial

About Me

My name is Oclemy, after recently finishing my Software Engineering undergraduate program, am now dedicating alot of time to my two babies: Camposha.info and my YouTube Channel ProgrammingWizards TV apart from my daily work.

Am committed to making them world class resources in the next few years. Help me by subscribing to my YouTube Channel ProgrammingWizards TV and sharing my articles.

Best Regards,

Oclemy.

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